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SEARCH STRATEGIES: We searched MEDLINE (1980 to 1998), psychological abstracts, ERIC and HealthStar databases, the Web site for The Journal of Family Practice, bibliographies of selected studies, and previous reviews for relevant articles. The search was limited to the English language. Three experts in the field of physical activity were contacted for leads on unpublished trials.
SELECTION CRITERIA: Inclusion criteria were: randomized controlled trial or quasiexperimental study using a comparison group, intervention delivered or initiated in a primary care setting, and reported results on at least 1 measure of physical activity. Studies that focused solely on patients with cardiovascular disease were excluded.
MAIN RESULTS: Primary care-based physical activity counseling is moderately effective in the short term, although there is considerable variability across studies. Studies in which the interventions were tailored to participant characteristics and which offered written materials to patients produced stronger results. Unlike many types of health promotion, the reach of primary care-based physical activity interventions is high. Questions remain about the consistency of implementation and long-term maintenance of outcomes.
CONCLUSIONS: Despite the need for further research, enough is known to recommend integration of key strategies of physical activity counseling into routine practice. We recommend incorporating these strategies into primary care and prioritizing them for further research.
What strategies are practical and effective to use in family practice settings to enhance levels of patient physical activity?
Regular physical activity is essential for disease prevention and health promotion.1-4 Even moderate levels of physical activity are associated with a reduced incidence of a variety of chronic conditions.1,3-7 National recommendations for physical activity from the American College of Sports Medicine and the Centers for Disease Control and Prevention state that all adults should accumulate 30 minutes a day of moderate intensity activity on 5 or more days per week. However, only 32% of US adults achieve that level.8
The National Health Promotion and Disease Prevention Objectives in Healthy People 20109-11 and the US Preventive Services Task Force12 recommend that physicians and other health care providers counsel their patients to be physically active, yet the majority of physicians do not. Two recent studies of older adults13,14 found that 48% and 36% reported having received advice regarding physical activity from their physicians. Barriers to such counseling include skepticism about its efficacy, competing demands, lack of time, lack of reimbursement, and the lack of standardized assessment and procedure protocols that would make counseling feasible to for busy office settings.15-17
We reviewed the literature on primary care-based physical activity interventions and offer evidence-based recommendations for incorporating them into practice. Our review differs from previous reviews of physical activity interventions in health care settings18-20 because we evaluate studies using the RE-AIM framework which was developed for evaluating the public health impact of health promotion activities. We also included a methodologic quality rating for each study and reported or calculated effect sizes and odds ratios where possible.
The RE-AIM Framework
The RE-AIM framework21 focuses attention on a real-world effectiveness perspective22 compatible with the realities of medical office treatment. There are 5 dimensions to the RE-AIM model that combine to determine the overall public health impact of an intervention. Two factors operate at the level of individual patients: Reach—the percentage and representativeness of patients who are willing to participate in a given procedure, and Efficacy—the impact of an intervention on behavioral, biologic, quality-of-life, and economic outcomes. There are also 2 less often studied but equally important dimensions that have an impact on a medical office or health care system: Adoption—the percentage and representativeness of settings that are willing to adopt an office innovation, and Implementation—the extent to which an intervention is delivered as intended. The fifth dimension, Maintenance, operates at both the individual and system levels. At the individual level, maintenance refers to the extent to which effects are stable long after an intervention is delivered. For this review, we adopted a minimum of a 1-year follow-up as criteria for demonstrating maintenance. At the systems level, maintenance refers to institutionalization of policies and practices such that they become routine.
These 5 factors interact to determine the overall population-based impact of a program. One implication of this model is that an intervention that generally does poorly on 1 or 2 dimensions (ie, fails to reach many patients or is implemented inconsistently) will have low overall public health impact. The RE-AIM evaluation framework was adopted because it relates more to practice-oriented research and real world concerns than other evaluation models and because it places equal emphasis on external validity (generalization) and internal validity, which is helpful in determining how relevant a study is for family practice.
Methods
We conducted electronic MEDLINE searches for the years 1980 to 1998 using Grateful Med and the National Library of Medicine’s PubMed search engines. We also performed computerized searches of psychological abstracts, ERIC and HealthStar databases, and of The Journal of Family Practice’s World WideWeb site (www.jfampract.com). The keywords we used for searching included: physical activity and randomized controlled trials, physical activity counseling and primary care or medical office, exercise interventions and primary care or medical office, and physical activity and health promotion. We limited the search to the English language. We searched bibliographies of selected studies and previous reviews for relevant articles. Finally, we contacted 3 experts in the field of physical activity for leads on unpublished trials. Although we attempted to be inclusive, our literature search may have been biased by the English language-only criterion and by the use of a single searcher.
The following inclusion criteria were used: randomized controlled trial or quasiexperimental study having a comparison group, intervention delivered or initiated in a primary care setting, and reported results on at least 1 measure of physical activity. We excluded studies that focused solely on patients with cardiovascular disease because they are generally considered to comprise a separate body of literature and not be representative of the larger population of patients seen in primary care.18 We identified 48 articles and retained 15 for the final review. The 33 not selected were not controlled trials, focused on a specific medical condition, or did not take place in a primary care setting. We contacted the authors of the 11 studies from which it was not possible to calculate effect size or odds ratio. Three authors responded with information adequate to perform the calculations.
The methodology rating we used was based on the RE-AIM model. RE-AIM was used rather than alternatives, such as the CONSORT criteria, because of its more balanced emphasis on internal and external validity and its relevance for practice-oriented research. The 6 criteria for rating methodology (and the possible points for each) are as follows:
Study design (0-3). One point was assigned for randomized studies. Two points were given to studies that used a placebo, equal contact control, or alternative treatment. One point was given for use of a comparison condition that controlled for a component of the intervention, usual care, or advice-only control groups.
Analyses (0-1). One point was given for analyses that controlled for potential confounding variables or adjusted for baseline physical activity.
Dependent variable (0-1). One point was given to studies that used previously validated outcome measures or that reported the reliability and validity of the physical activity measure.
Reach (0-1). One point was given to studies reporting on the percentage or representativeness of participants.
Implementation (0-2). One point was given to studies for which the intervention was conducted by clinic staff. An additional point was given if the quality of the intervention implementation was reported.
Attrition (0-2). One point was given if attrition was reported. An additional point was given if the rate of attrition was 10% or less or if an intention-to-treat analysis or imputation of missing data was used.
Results
The Table shows descriptive information and short- and long-term outcomes for the 15 studies we reviewed. It includes the methodology rating, sample size, study design and the physical activity intervention (ie, length and content), outcome variables and length of follow-up, and outcomes presented in terms of effect sizes for continuous variables and odds ratios for dichotomous variables for both short-term (less than 12 months) and long-term (12 months or longer) outcomes. Interrater reliability between the 2 independent raters on the methodology score was rho = 0.85, and disagreements were resolved by conference with the senior author.
Outcomes
Of the 10 studies reporting 0- to 11-month post- intervention outcomes, 7 reported statistically significant physical activity outcomes. Effect sizes ranged from 0.003 to 0.26 and odds ratios from 1.04 to 3.73 (median = 1.88). Of the 7 studies reporting postintervention outcomes at 12 months or longer, 3 reported statistically significant outcomes. The only study among these from which an effect size could be calculated reported d = 0.09, and follow-up odds ratios ranged from 0.09 to 1.39 (median = 1.25). Unfortunately, it is not possible to summarize these outcomes in a straightforward manner, such as percentage of patients who changed from being sedentary to meeting the new guidelines for regular moderate physical activity or number needed to treat. This is because rather than using standard measures of physical activity, the authors of most of the studies developed or selected their own continuous (for which we have presented mean effect size) or dichotomous physical activity measures (for which we have presented odds ratios). What can be said is that well-controlled physical activity studies have generally produced moderate short-term improvements, but these results are often less encouraging at long-term follow-up.
Methodology Rating
The methodology rating scores for the studies we included ranged from 4 to 9, with the majority receiving a score of 6 or 7 on the scale of 0 to 10. Overall, the study designs were strong, with the vast majority being randomized trials that studied relatively large samples, employed appropriate analyses, and reported on attrition rates. The methodologic areas in which studies were downgraded most often were for not reporting implementation results and failing to employ intention-to-treat analyses or imputation procedures to address attrition issues. There was not a strong relationship between methodologic quality and intervention effectiveness. Five of the 10 studies with significant effects had methodology ratings of 7 or higher.
Sample
Study sample sizes ranged from small (N = 63) to large (N = 6124). Although all but one study included both men and women, the percentage of women was greater in most studies. All studies focused on adults, with an age range of 18 years to 75 years and older. Four studies included only adults 50 years and older, and none demonstrated significant short-term results, though one achieved long-term outcomes. Seven studies included only sedentary patients, although the definition of sedentary was not consistent across studies; the other 8 studies included patients with a range of or unspecified baseline physical activity levels.
In 12 studies, the bulk of the physical activity (or multiple risk factor) intervention was delivered during a routine primary care visit. In the other 3, a portion of the intervention took place in classes or groups outside of the primary care setting. The intervention was delivered by physicians in 9 studies, by nurses in 3 studies, by a physician and a health educator in 2 studies, and by public health students in 1 study. No clear relationship emerged between type of interventionist and effectiveness. Of the 7 studies with significant short-term effects, 4 had physicians deliver the intervention, one used nurse delivery, and 2 used delivery by a physician and health educator combination. Of the 3 studies with significant long-term effects, one was delivered by physicians, one by nurses, and one by public health students.
Study Design and Physical Activity Intervention
Nine studies employed a randomized controlled trial. In 8 studies, physical activity was the sole focus of the intervention; in 7 studies, the physical activity intervention was part of a multiple risk factor intervention, including behaviors such as smoking, diet, alcohol and seat belt use. Physical activity-only interventions faired better in the short term than multiple risk factor interventions; 6 of the 7 studies with significant short-term effects focused on physical activity only. In contrast, all 3 of the studies with significant long-term effects were multiple risk factor interventions. Walking was the most common activity recommendation.
The length of the initial provider-delivered intervention varied greatly—from 3 to 10 minutes of physical activity counseling in 7 studies to 15 to 120 minutes of multiple risk factor counseling in 3 studies. Brief counseling may be as effective as more lengthy counseling, since 5 of the 7 studies with significant short-term effects involved 3- to 10-minute counseling sessions. The majority of the studies provided at least some details about the amount of provider training regarding the physical activity (or multiple risk factor) intervention, which ranged from 15 minutes of individual training and the provision of tip sheets to 2-hour workshops.
Ten of the 15 studies involved interventions that were tailored to patient characteristics, such as readiness to exercise, baseline levels of physical activity, or physical activity preferences. Tailoring seemed to affect short-term physical activity outcomes, with 6 of the 7 studies with significant short-term effects using some form of tailored intervention. Of the 3 studies with significant long-term effects, only one involved a tailored intervention. Eleven of 15 studies used written materials that ranged from brief physical activity tip sheets to more extensive physical activity manuals. The use of written materials also seemed to have an impact on short-term outcomes, with 6 of 7 studies with short-term effects offering them to their patients. Two of the 3 studies with significant long-term effects used written materials to accompany the intervention. Six of the 15 studies included some form of follow-up support for the patient—3 offered an additional physician office visit, one used a phone call from the health educator, and 3 used tailored mailed physical activity pamphlets. There was no clear advantage of the use of follow-up support; only 3 of the 10 studies with significant effects used them.
Theory-Based Interventions
Seven of the 15 studies described the theoretical basis of the physical activity intervention employed. All explicitly theory-based physical activity interventions used at least some of, if not all, the components of social-cognitive theory23,24 or self-management/behavior change interventions (eg, assessment and feedback, goal-setting, identification of barriers to change, personalized problem solving, reinforcement, and supportive follow-up).24-27 Four studies employed a transtheoretical model or “stages of change” theoretical perspective.28,29 Three of these 4 studies failed to find significant short-term effects.19,30,31 Overall, theory-based physical activity interventions were not any more effective than those not based on explicit theories of behavior change; only 4 of the 10 studies with significant effects were based on explicit theories of behavior change.
Key Physical Activity Outcome and Length of Follow-Up
Studies used a wide range of physical activity outcome variables, with varying definitions of sedentary lifestyle, regular and moderate activity, and vigorous exercise. All studies relied on patient self-reports of physical activity, with one study using activity monitors and one including a measure of physical fitness (VO2 max) to corroborate self-report. In both studies, the significant intervention effect on the self-reported physical activity outcomes was corroborated by this additional activity monitor or fitness data. Length of follow-up ranged from 4 weeks to 4 years, with 7 studies reporting follow-ups of 12 months or longer. Few studies reported on outcomes other than physical activity or the multiple risk factors associated with the intervention. Three studies assessed body mass index, one assessed cholesterol and blood pressure, 2 assessed quality of life, and one reported on cost-effectiveness.
Although the majority of studies did not specifically report on subject attrition, it was possible to calculate attrition rates for all studies. Attrition was moderately high and ranged from 1% to 44% (median = 18%) at follow-ups of fewer than 12 months, and 20% to 56% (median = 41%) at longer-term follow-ups. Only 4 of the 11 studies with attrition rates of 15% or higher used intention-to-treat analyses or imputation methods to address attrition. Those patients who dropped out tended to be less educated, more likely to smoke, and in poorer health.
RE-AIM Criteria
Eleven of 15 studies reported on the percentage of the eligible population who agreed to participate (Reach), ranging from 35% to 100% (median = 74%), but only 3 of those described whether enrolled subjects were representative of the larger population from which the sample was drawn. In all 3 studies, participants differed from nonparticipants on demographic variables such as sex and smoking status, raising concerns about the representativeness of the samples studied. In contrast, only 3 studies reported on the percentage of eligible primary care settings and providers who agreed to participate in the study (Adoption).
The authors of 12 studies reported at least some data on intervention implementation. The most common implementation measures were whether patients attended a visit or whether physicians delivered advice. Implementation for these relatively crude indices was variable (range = 30%-100%) but generally high, especially for delivery of advice (80%-100%).
In terms of efficacy, of the 10 studies reporting 0- to 11-month postintervention outcomes, 7 reported statistically significant physical activity outcomes. Regarding maintenance, of the 7 studies reporting 12-month or longer postintervention outcomes, 3 reported statistically significant outcomes. As in other health behavior change areas, it appears challenging to maintain initial treatment effects. Two of the 3 studies reporting both short-term and long-term results32,33 found significant efficacy results at initial follow-ups, but in all 3 studies results were no longer significant at later follow-up.
Discussion
Brief primary care-based physical activity interventions are effective in producing moderate short-term improvements in self-reported physical activity levels. Of the 10 studies reporting short-term outcomes, 7 reported statistically significant results. A more detailed evaluation of intervention characteristics revealed a number of factors associated with successful outcomes, including brief interventions (of 3 to 10 minutes) that focused on physical activity only, were tailored to patient characteristics and preferences, and included supplemental written materials. In contrast, longer interventions focusing on multiple risk factors that did not include written patient materials did not achieve significant short-term results for physical activity. Short-term improvements on physical activity were observed across all types of interventionists, including physicians, nurses, and combinations of physicians and health educators.
There are some intervention components that seem logical that we cannot recommend. Unlike the literature in other health behavior change areas,34,35 the use of follow-up supports after the initial intervention did not increase the likelihood of positive short-term results. Another surprise was that theory-based interventions did not appear more successful than those not explicitly theory based; specifically, interventions using the transtheoretical model were not effective. None of the studies that focused solely on older adults (those aged 50 years and older) achieved positive short-term results, indicating that this is an area in need of further attention. The issue of long-term effectiveness is difficult to evaluate. Only 7 studies reported long-term outcomes, and only 3 of those achieved significant results.
RE-AIM Conclusions
Compared with the general health promotion literature, more studies reported on the Reach and representativeness of participants than is typically observed,36-38 and these results were encouraging. Primary care-based physical activity interventions are an effective means of reaching a large segment of sedentary adults, although the representativeness of study samples remains unclear. Men, smokers, and older adults appear less likely to participate in physical activity interventions.
Our review revealed a solid body of research documenting the Efficacy of primary care-based physical activity interventions. There has been far less research on Adoption of primary care-based physical activity interventions. Only 3 studies reported on adoption, and none of these addressed whether the participating providers or practices were representative. Much more research is needed on intervention and clinic characteristics associated with adoption. The representativeness of the settings and clinicians participating in health behavior change research is equally important as the representativeness of the patients studied.
Approximately 75% of the studies reported on Implementation. Brief physician counseling can be consistently implemented. Other intervention components, such as repeat visits and follow-up counseling, appear more difficult to deliver consistently.
Although brief, primary care-based interventions appear efficacious in producing short-term changes in physical activity, Maintenance remains difficult. This is true not only for physical activity, but also for the majority of health promotion/disease management behaviors prescribed by physicians (eg, medication taking, smoking cessation, dietary change).34,39
Directions for Future Research
Maintenance of short-term intervention gains in physical activity is a key issue for future research. A National Heart, Lung, and Blood Institute-sponsored collaborative trial (the Activity Counseling Trial) is underway to address this issue.41 Other ways to affect maintenance that warrant further evaluation include assisting patients in using available community physical activity resources26,42,43 and the use of technological supports (eg, the Internet, tailored print materials, and automated phone prompts).17,44,45
An evaluation of the strengths and limitations of different delivery models, such as provider-delivered versus computer-delivered physical activity counseling would also make a significant contribution to the physical activity intervention literature. In the areas of smoking and dietary change, many successful interventions have been developed in which the physician provides brief advice only and then nonphysician providers or other office staff deliver the majority of the intervention46,47 Given time constraints on physicians in most medical settings, the use of nonphysician delivery models warrants further investigation in the area of physical activity.
Finally, cost-effective ways to deliver physical activity counseling to older patients and to conduct follow-up are needed.
Recommendations for clinical practice
Health care providers can implement moderately effective brief physical activity interventions following brief training during the course of routine health care delivery. We have 3 specific evidence-based recommendations. These recommendations primarily address how to achieve short-term changes in patient physical activity. The issue of long-term maintenance is more complex.
* An initial focus on physical activity only, as opposed to multiple risk factors, is recommended, although maintenance may be enhanced when supported over time by other risk factor interventions.
* Tailored interventions and written materials enhance success rates. The most basic written materials are standard pamphlets on physical activity available from organizations such as the American Heart Association and the American Lung Association. More effective print materials based on this review and a growing literature40 would be tailored to patient characteristics and preferences. Although such tailored print materials are not commonly available, health care providers might consider a 1-page physical activity prescription form. Such a form would indicate the physical activity goal, the specific behaviors the patient should engage in, the primary barriers the patient anticipates will get in the way of the goal and suggestions for overcoming the barriers, and identification of sources of support for physical activity.
* Physical activity counseling can be successfully implemented by a variety of health care team members. The person who delivers the intervention should be whomever is most likely to do so consistently, given time, training, and interest.
1. US Department of Health and Human Services. Physical activity and health: a report of the Surgeon General Executive Summary. Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, The President’s Council on Physical Fitness and Sports. Atlanta, Ga: US Government Printing Office; 1996.
2. National Institutes of Health. Physical activity and cardiovascular health. JAMA 1996;76:241-6.
3. Harris SS, Caspersen CJ, DeFriese GH, et al. Physical activity counseling for healthy adults as a primary preventive intervention in the clinical setting: report for the US Preventive Services Task Force. JAMA 1989;261:3590-8.
4. Pate RR, Pratt M, Blair SN, et al. Physical activity and public health: a recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 1995;273:402-7.
5. Paffenbarger RS, Hyde RT, Wing AL, Hsieh C-C. Physical activity, all-cause mortality, and longevity of college alumni. N Eng J Med 1986;314:605-13.
6. US Department of Health and Human Services. Health promotion and older adults. Prev Rep 1989;1-5.
7. Clark NM, Becker MH, Janz NK, Lorig K, Rakowski W, Anderson L. Self-management of chronic disease by older adults. J Aging Health 1991;3:3-27.
8. Jones DA, Ainsworth BE, Croft JB, Macera CA, Lloyd EE, Yusuf HR. Moderate leisure-time physical activity: Who is meeting the public health recommendations? A national cross-sectional study. Arch Fam Med 1998;7:285-9.
9. US Department of Health and Human Services Office Public Health and Science. Healthy people 2010 objectives: draft for public comment. 1998.
10. Pinto BM, Goldstein MG, Marcus BH. Activity counseling by primary care physicians. Prev Med 1998;27:506-13.
11. US Department of Health and Human Services. Promoting health/preventing disease year 2000 health objectives for the nation. 1990.
12. US Preventive Services Task Force. Guide to clinical preventive services: an assessment of the effectiveness of 169 interventions. Baltimore, Md: Williams & Wilkins, 1989.
13. Damush TM, Stewart AL, Millls K, King AC, Ritter PL. Prevalence and correlates of physician recommendations to older adults to exercise. Ann Behav Med 1998;20:S194.-
14. Eakin EG, Glasgow RE. Recruitment of managed care Medicare patients for a physical activity study. Am J Health Promo 1997;12:98.-
15. Beaven DW, Scott RS. The organization of diabetes care. In: Alberti KGMM, Krall LP, eds. The diabetes annual 2. New York, NY: Elsevier; 1986;39-48.
16. Orlandi MA. Promoting health and preventing disease in health care settings: an analysis of barriers. Prev Med 1987;16:119-30.
17. Glasgow RE, McKay HG, Boles SM, Vogt TV. Interactive technology, behavioral science, and health care: progress, pitfalls, and promise. J Fam Pract 1999;48:464-70.
18. Simons-Morton DG, Calfas KJ, Oldenburg B, Burton NW. Effects of interventions in health care settings on physical activity or cardiorespiratory fitness. Am J Prev Med 1998;15:413-30.
19. Goldstein MG, Pinto BM, Marcus BH, et al. Physician-based physical activity counseling for middle-aged and older adults: a randomized trial. Ann Behav Med In press.
20. Eaton CB, Menard LM. A systematic review of physical activity promotion in primary care office settings. Br J Sports Med 1998;32:11-6.
21. Glasgow RE, Vogt TM, Boles SM. Evaluating the public health impact of health promotion interventions: the RE-AIM framework. Am J Public Health In press.
22. Flay BR. Efficacy and effectiveness trials (and other phases of research) in the development of health promotion programs. Prev Med 1986;15:451-74.
23. Bandura A. Social foundations of thought and action: a social cognitive theory. Englewood Cliffs, NJ: Prentice Hall; 1986.
24. Bandura A. Self-efficacy: the exercise of control. New York, NY: W.H. Freeman, 1997.
25. Strecher VJ, Seijts GH, Kok GJ, et al. Goal setting as a strategy for health behavior change. Health Educ Q 1995;22:190-200.
26. Glasgow RE, Eakin EG. Medical office-based interventions. In: Snoek FJ, Skinner CS, eds. Psychological aspects of diabetes care. In press.
27. Wagner EH, Austin B, Von Korff M. Improving outcomes in chronic illness. Manag Care Q 1996;4:12-25.
28. Prochaska JO, Velicer WF, Rossi JS, et al. Stages of change and decisional balance for 12 problem behaviors. Health Psychol 1994;13:39-46.
29. Marcus BH, Rakowski W, Rossi JS. Assessing motivational readiness and decision-making for exercise. Health Psychol 1992;11:2457-61.
30. Marcus BH, Goldstein MG, Jette AM. Training physicians to conduct physical activity counseling. Prev Med 1997;26:382-8.
31. Graham-Clarke P, Oldenburg B. The effectiveness of a general-practice-based physical activity intervention on patient physical activity status. Behavior Change 1994;11:132-44.
32. Bull FC, Jamrozik K. Advice on exercise from a family physician can help sedentary patients to become active. Am J Prev Med 1998;15:85-94.
33. Reid LR, Morgan RW. Exercise prescription: a clinical trial. Am J Public Health 1979;69:591-5.
34. Gochman DS, Gochman DS, eds. Handbook of health behavior research II. New York, NY: Plenum Press; 1997.
35. Glasgow RE, Eakin EG. Issues in diabetes self-management. In: Shumaker SA, Schron EB, Ockene JK, McBee WL, eds. The handbook of health behavior change. 2nd ed. New York, NY: Springer Publishing Company, 1998;435-61.
36. Glasgow RE, Eakin EG, Toobert DJ. How generalizable are the results of diabetes self-management research? The impact of participation and attrition. Diabetes Educ 1996;22:573-85.
37. Glasgow RE, McCaul KD, Fisher KJ. Participation in worksite health promotion: a critique of the literature and recommendations for future practice. Health Educ Q 1993;20:391-408.
38. Sorensen G, Emmons KM, Hunt MK, Johnston D. Implications of the results of the community intervention trials. Annu Rev Public Health 1998;19:379-416.
39. Orleans CT. Treating nicotine dependence in medical settings: a stepped-care model. In: Orleans CT, Slade J, eds. Nicotine addiction: principles and management. New York, NY: Oxford University Press, 1993;145-62.
40. de Vries H, Brug J. Computer-tailored interventions motivating people to adopt health promoting behaviors: Introduction to a new approach. Patient Educ Couns 1999;36:99-105.
41. King AC, Sallis JF, Dunn AL, et al. Overview of the Activity Counseling Trial (ACT) intervention for promoting physical activity in primary health care settings. Med Sci Sports Exerc 1998;30:1086-96.
42. Stewart AL, Sepsis PG, King AC, McLelland BY, Roitz K, Ritter PL. Evaluation of CHAMPS, a physical activity promotion program for older adults. Ann Behav Med 1997;19:353-61.
43. Sallis JF, Owen N. Physical activity and behavioral medicine. Turner JR, ed. Thousand Oaks, Calif: Sage Publications; 1999.
44. Piette JD, McPhee SJ, Weinberger M, Mah CA, Kraemer FB. Can patients with diabetes use automated telephone disease management calls effectively? In press.
45. Piette JD, Mah CA. The feasibility of automated voice messaging as an adjunct to outpatient diabetes care. Diabetes Care 1997;20:15-21.
46. Hollis JF, Lichtenstein E, Vogt TM, Stevens VJ, Biglan A. Nurse-assisted counseling for smokers in primary care. Ann Intern Med 1993;118:521-5.
47. Glasgow RE, La Chance P, Toobert DJ, Brown J, Hampson SE, Riddle MC. Long-term effects and costs of brief behavioral dietary intervention for patients with diabetes delivered from the medical office. Patient Educ Couns 1997;32:175-84.
48. Elder JP, Wright BL. Longitudinal effects of preventive services on health behaviors among an elderly cohort. Am J Prev Med 1995;11:354-8.
49. Jette AM, Lachman M, Giorgetti MM, et al. Exercise—it’s never too late: the Strong-for-Life Program. AM J Public Health 1999;89:66-72.
50. King AC, Oka R, Pruitt L, Philips W. Developing optimal exercise regimens for seniors: a clinical trial. Ann Behav Med 1997;19:S056.-
51. Pereira MA, FitzGerald SJ, Gregg EW, et al. A collection of physical activity questionnaires for health-related research. Med Sci Sports Exer 1997;29:S1-205.
SEARCH STRATEGIES: We searched MEDLINE (1980 to 1998), psychological abstracts, ERIC and HealthStar databases, the Web site for The Journal of Family Practice, bibliographies of selected studies, and previous reviews for relevant articles. The search was limited to the English language. Three experts in the field of physical activity were contacted for leads on unpublished trials.
SELECTION CRITERIA: Inclusion criteria were: randomized controlled trial or quasiexperimental study using a comparison group, intervention delivered or initiated in a primary care setting, and reported results on at least 1 measure of physical activity. Studies that focused solely on patients with cardiovascular disease were excluded.
MAIN RESULTS: Primary care-based physical activity counseling is moderately effective in the short term, although there is considerable variability across studies. Studies in which the interventions were tailored to participant characteristics and which offered written materials to patients produced stronger results. Unlike many types of health promotion, the reach of primary care-based physical activity interventions is high. Questions remain about the consistency of implementation and long-term maintenance of outcomes.
CONCLUSIONS: Despite the need for further research, enough is known to recommend integration of key strategies of physical activity counseling into routine practice. We recommend incorporating these strategies into primary care and prioritizing them for further research.
What strategies are practical and effective to use in family practice settings to enhance levels of patient physical activity?
Regular physical activity is essential for disease prevention and health promotion.1-4 Even moderate levels of physical activity are associated with a reduced incidence of a variety of chronic conditions.1,3-7 National recommendations for physical activity from the American College of Sports Medicine and the Centers for Disease Control and Prevention state that all adults should accumulate 30 minutes a day of moderate intensity activity on 5 or more days per week. However, only 32% of US adults achieve that level.8
The National Health Promotion and Disease Prevention Objectives in Healthy People 20109-11 and the US Preventive Services Task Force12 recommend that physicians and other health care providers counsel their patients to be physically active, yet the majority of physicians do not. Two recent studies of older adults13,14 found that 48% and 36% reported having received advice regarding physical activity from their physicians. Barriers to such counseling include skepticism about its efficacy, competing demands, lack of time, lack of reimbursement, and the lack of standardized assessment and procedure protocols that would make counseling feasible to for busy office settings.15-17
We reviewed the literature on primary care-based physical activity interventions and offer evidence-based recommendations for incorporating them into practice. Our review differs from previous reviews of physical activity interventions in health care settings18-20 because we evaluate studies using the RE-AIM framework which was developed for evaluating the public health impact of health promotion activities. We also included a methodologic quality rating for each study and reported or calculated effect sizes and odds ratios where possible.
The RE-AIM Framework
The RE-AIM framework21 focuses attention on a real-world effectiveness perspective22 compatible with the realities of medical office treatment. There are 5 dimensions to the RE-AIM model that combine to determine the overall public health impact of an intervention. Two factors operate at the level of individual patients: Reach—the percentage and representativeness of patients who are willing to participate in a given procedure, and Efficacy—the impact of an intervention on behavioral, biologic, quality-of-life, and economic outcomes. There are also 2 less often studied but equally important dimensions that have an impact on a medical office or health care system: Adoption—the percentage and representativeness of settings that are willing to adopt an office innovation, and Implementation—the extent to which an intervention is delivered as intended. The fifth dimension, Maintenance, operates at both the individual and system levels. At the individual level, maintenance refers to the extent to which effects are stable long after an intervention is delivered. For this review, we adopted a minimum of a 1-year follow-up as criteria for demonstrating maintenance. At the systems level, maintenance refers to institutionalization of policies and practices such that they become routine.
These 5 factors interact to determine the overall population-based impact of a program. One implication of this model is that an intervention that generally does poorly on 1 or 2 dimensions (ie, fails to reach many patients or is implemented inconsistently) will have low overall public health impact. The RE-AIM evaluation framework was adopted because it relates more to practice-oriented research and real world concerns than other evaluation models and because it places equal emphasis on external validity (generalization) and internal validity, which is helpful in determining how relevant a study is for family practice.
Methods
We conducted electronic MEDLINE searches for the years 1980 to 1998 using Grateful Med and the National Library of Medicine’s PubMed search engines. We also performed computerized searches of psychological abstracts, ERIC and HealthStar databases, and of The Journal of Family Practice’s World WideWeb site (www.jfampract.com). The keywords we used for searching included: physical activity and randomized controlled trials, physical activity counseling and primary care or medical office, exercise interventions and primary care or medical office, and physical activity and health promotion. We limited the search to the English language. We searched bibliographies of selected studies and previous reviews for relevant articles. Finally, we contacted 3 experts in the field of physical activity for leads on unpublished trials. Although we attempted to be inclusive, our literature search may have been biased by the English language-only criterion and by the use of a single searcher.
The following inclusion criteria were used: randomized controlled trial or quasiexperimental study having a comparison group, intervention delivered or initiated in a primary care setting, and reported results on at least 1 measure of physical activity. We excluded studies that focused solely on patients with cardiovascular disease because they are generally considered to comprise a separate body of literature and not be representative of the larger population of patients seen in primary care.18 We identified 48 articles and retained 15 for the final review. The 33 not selected were not controlled trials, focused on a specific medical condition, or did not take place in a primary care setting. We contacted the authors of the 11 studies from which it was not possible to calculate effect size or odds ratio. Three authors responded with information adequate to perform the calculations.
The methodology rating we used was based on the RE-AIM model. RE-AIM was used rather than alternatives, such as the CONSORT criteria, because of its more balanced emphasis on internal and external validity and its relevance for practice-oriented research. The 6 criteria for rating methodology (and the possible points for each) are as follows:
Study design (0-3). One point was assigned for randomized studies. Two points were given to studies that used a placebo, equal contact control, or alternative treatment. One point was given for use of a comparison condition that controlled for a component of the intervention, usual care, or advice-only control groups.
Analyses (0-1). One point was given for analyses that controlled for potential confounding variables or adjusted for baseline physical activity.
Dependent variable (0-1). One point was given to studies that used previously validated outcome measures or that reported the reliability and validity of the physical activity measure.
Reach (0-1). One point was given to studies reporting on the percentage or representativeness of participants.
Implementation (0-2). One point was given to studies for which the intervention was conducted by clinic staff. An additional point was given if the quality of the intervention implementation was reported.
Attrition (0-2). One point was given if attrition was reported. An additional point was given if the rate of attrition was 10% or less or if an intention-to-treat analysis or imputation of missing data was used.
Results
The Table shows descriptive information and short- and long-term outcomes for the 15 studies we reviewed. It includes the methodology rating, sample size, study design and the physical activity intervention (ie, length and content), outcome variables and length of follow-up, and outcomes presented in terms of effect sizes for continuous variables and odds ratios for dichotomous variables for both short-term (less than 12 months) and long-term (12 months or longer) outcomes. Interrater reliability between the 2 independent raters on the methodology score was rho = 0.85, and disagreements were resolved by conference with the senior author.
Outcomes
Of the 10 studies reporting 0- to 11-month post- intervention outcomes, 7 reported statistically significant physical activity outcomes. Effect sizes ranged from 0.003 to 0.26 and odds ratios from 1.04 to 3.73 (median = 1.88). Of the 7 studies reporting postintervention outcomes at 12 months or longer, 3 reported statistically significant outcomes. The only study among these from which an effect size could be calculated reported d = 0.09, and follow-up odds ratios ranged from 0.09 to 1.39 (median = 1.25). Unfortunately, it is not possible to summarize these outcomes in a straightforward manner, such as percentage of patients who changed from being sedentary to meeting the new guidelines for regular moderate physical activity or number needed to treat. This is because rather than using standard measures of physical activity, the authors of most of the studies developed or selected their own continuous (for which we have presented mean effect size) or dichotomous physical activity measures (for which we have presented odds ratios). What can be said is that well-controlled physical activity studies have generally produced moderate short-term improvements, but these results are often less encouraging at long-term follow-up.
Methodology Rating
The methodology rating scores for the studies we included ranged from 4 to 9, with the majority receiving a score of 6 or 7 on the scale of 0 to 10. Overall, the study designs were strong, with the vast majority being randomized trials that studied relatively large samples, employed appropriate analyses, and reported on attrition rates. The methodologic areas in which studies were downgraded most often were for not reporting implementation results and failing to employ intention-to-treat analyses or imputation procedures to address attrition issues. There was not a strong relationship between methodologic quality and intervention effectiveness. Five of the 10 studies with significant effects had methodology ratings of 7 or higher.
Sample
Study sample sizes ranged from small (N = 63) to large (N = 6124). Although all but one study included both men and women, the percentage of women was greater in most studies. All studies focused on adults, with an age range of 18 years to 75 years and older. Four studies included only adults 50 years and older, and none demonstrated significant short-term results, though one achieved long-term outcomes. Seven studies included only sedentary patients, although the definition of sedentary was not consistent across studies; the other 8 studies included patients with a range of or unspecified baseline physical activity levels.
In 12 studies, the bulk of the physical activity (or multiple risk factor) intervention was delivered during a routine primary care visit. In the other 3, a portion of the intervention took place in classes or groups outside of the primary care setting. The intervention was delivered by physicians in 9 studies, by nurses in 3 studies, by a physician and a health educator in 2 studies, and by public health students in 1 study. No clear relationship emerged between type of interventionist and effectiveness. Of the 7 studies with significant short-term effects, 4 had physicians deliver the intervention, one used nurse delivery, and 2 used delivery by a physician and health educator combination. Of the 3 studies with significant long-term effects, one was delivered by physicians, one by nurses, and one by public health students.
Study Design and Physical Activity Intervention
Nine studies employed a randomized controlled trial. In 8 studies, physical activity was the sole focus of the intervention; in 7 studies, the physical activity intervention was part of a multiple risk factor intervention, including behaviors such as smoking, diet, alcohol and seat belt use. Physical activity-only interventions faired better in the short term than multiple risk factor interventions; 6 of the 7 studies with significant short-term effects focused on physical activity only. In contrast, all 3 of the studies with significant long-term effects were multiple risk factor interventions. Walking was the most common activity recommendation.
The length of the initial provider-delivered intervention varied greatly—from 3 to 10 minutes of physical activity counseling in 7 studies to 15 to 120 minutes of multiple risk factor counseling in 3 studies. Brief counseling may be as effective as more lengthy counseling, since 5 of the 7 studies with significant short-term effects involved 3- to 10-minute counseling sessions. The majority of the studies provided at least some details about the amount of provider training regarding the physical activity (or multiple risk factor) intervention, which ranged from 15 minutes of individual training and the provision of tip sheets to 2-hour workshops.
Ten of the 15 studies involved interventions that were tailored to patient characteristics, such as readiness to exercise, baseline levels of physical activity, or physical activity preferences. Tailoring seemed to affect short-term physical activity outcomes, with 6 of the 7 studies with significant short-term effects using some form of tailored intervention. Of the 3 studies with significant long-term effects, only one involved a tailored intervention. Eleven of 15 studies used written materials that ranged from brief physical activity tip sheets to more extensive physical activity manuals. The use of written materials also seemed to have an impact on short-term outcomes, with 6 of 7 studies with short-term effects offering them to their patients. Two of the 3 studies with significant long-term effects used written materials to accompany the intervention. Six of the 15 studies included some form of follow-up support for the patient—3 offered an additional physician office visit, one used a phone call from the health educator, and 3 used tailored mailed physical activity pamphlets. There was no clear advantage of the use of follow-up support; only 3 of the 10 studies with significant effects used them.
Theory-Based Interventions
Seven of the 15 studies described the theoretical basis of the physical activity intervention employed. All explicitly theory-based physical activity interventions used at least some of, if not all, the components of social-cognitive theory23,24 or self-management/behavior change interventions (eg, assessment and feedback, goal-setting, identification of barriers to change, personalized problem solving, reinforcement, and supportive follow-up).24-27 Four studies employed a transtheoretical model or “stages of change” theoretical perspective.28,29 Three of these 4 studies failed to find significant short-term effects.19,30,31 Overall, theory-based physical activity interventions were not any more effective than those not based on explicit theories of behavior change; only 4 of the 10 studies with significant effects were based on explicit theories of behavior change.
Key Physical Activity Outcome and Length of Follow-Up
Studies used a wide range of physical activity outcome variables, with varying definitions of sedentary lifestyle, regular and moderate activity, and vigorous exercise. All studies relied on patient self-reports of physical activity, with one study using activity monitors and one including a measure of physical fitness (VO2 max) to corroborate self-report. In both studies, the significant intervention effect on the self-reported physical activity outcomes was corroborated by this additional activity monitor or fitness data. Length of follow-up ranged from 4 weeks to 4 years, with 7 studies reporting follow-ups of 12 months or longer. Few studies reported on outcomes other than physical activity or the multiple risk factors associated with the intervention. Three studies assessed body mass index, one assessed cholesterol and blood pressure, 2 assessed quality of life, and one reported on cost-effectiveness.
Although the majority of studies did not specifically report on subject attrition, it was possible to calculate attrition rates for all studies. Attrition was moderately high and ranged from 1% to 44% (median = 18%) at follow-ups of fewer than 12 months, and 20% to 56% (median = 41%) at longer-term follow-ups. Only 4 of the 11 studies with attrition rates of 15% or higher used intention-to-treat analyses or imputation methods to address attrition. Those patients who dropped out tended to be less educated, more likely to smoke, and in poorer health.
RE-AIM Criteria
Eleven of 15 studies reported on the percentage of the eligible population who agreed to participate (Reach), ranging from 35% to 100% (median = 74%), but only 3 of those described whether enrolled subjects were representative of the larger population from which the sample was drawn. In all 3 studies, participants differed from nonparticipants on demographic variables such as sex and smoking status, raising concerns about the representativeness of the samples studied. In contrast, only 3 studies reported on the percentage of eligible primary care settings and providers who agreed to participate in the study (Adoption).
The authors of 12 studies reported at least some data on intervention implementation. The most common implementation measures were whether patients attended a visit or whether physicians delivered advice. Implementation for these relatively crude indices was variable (range = 30%-100%) but generally high, especially for delivery of advice (80%-100%).
In terms of efficacy, of the 10 studies reporting 0- to 11-month postintervention outcomes, 7 reported statistically significant physical activity outcomes. Regarding maintenance, of the 7 studies reporting 12-month or longer postintervention outcomes, 3 reported statistically significant outcomes. As in other health behavior change areas, it appears challenging to maintain initial treatment effects. Two of the 3 studies reporting both short-term and long-term results32,33 found significant efficacy results at initial follow-ups, but in all 3 studies results were no longer significant at later follow-up.
Discussion
Brief primary care-based physical activity interventions are effective in producing moderate short-term improvements in self-reported physical activity levels. Of the 10 studies reporting short-term outcomes, 7 reported statistically significant results. A more detailed evaluation of intervention characteristics revealed a number of factors associated with successful outcomes, including brief interventions (of 3 to 10 minutes) that focused on physical activity only, were tailored to patient characteristics and preferences, and included supplemental written materials. In contrast, longer interventions focusing on multiple risk factors that did not include written patient materials did not achieve significant short-term results for physical activity. Short-term improvements on physical activity were observed across all types of interventionists, including physicians, nurses, and combinations of physicians and health educators.
There are some intervention components that seem logical that we cannot recommend. Unlike the literature in other health behavior change areas,34,35 the use of follow-up supports after the initial intervention did not increase the likelihood of positive short-term results. Another surprise was that theory-based interventions did not appear more successful than those not explicitly theory based; specifically, interventions using the transtheoretical model were not effective. None of the studies that focused solely on older adults (those aged 50 years and older) achieved positive short-term results, indicating that this is an area in need of further attention. The issue of long-term effectiveness is difficult to evaluate. Only 7 studies reported long-term outcomes, and only 3 of those achieved significant results.
RE-AIM Conclusions
Compared with the general health promotion literature, more studies reported on the Reach and representativeness of participants than is typically observed,36-38 and these results were encouraging. Primary care-based physical activity interventions are an effective means of reaching a large segment of sedentary adults, although the representativeness of study samples remains unclear. Men, smokers, and older adults appear less likely to participate in physical activity interventions.
Our review revealed a solid body of research documenting the Efficacy of primary care-based physical activity interventions. There has been far less research on Adoption of primary care-based physical activity interventions. Only 3 studies reported on adoption, and none of these addressed whether the participating providers or practices were representative. Much more research is needed on intervention and clinic characteristics associated with adoption. The representativeness of the settings and clinicians participating in health behavior change research is equally important as the representativeness of the patients studied.
Approximately 75% of the studies reported on Implementation. Brief physician counseling can be consistently implemented. Other intervention components, such as repeat visits and follow-up counseling, appear more difficult to deliver consistently.
Although brief, primary care-based interventions appear efficacious in producing short-term changes in physical activity, Maintenance remains difficult. This is true not only for physical activity, but also for the majority of health promotion/disease management behaviors prescribed by physicians (eg, medication taking, smoking cessation, dietary change).34,39
Directions for Future Research
Maintenance of short-term intervention gains in physical activity is a key issue for future research. A National Heart, Lung, and Blood Institute-sponsored collaborative trial (the Activity Counseling Trial) is underway to address this issue.41 Other ways to affect maintenance that warrant further evaluation include assisting patients in using available community physical activity resources26,42,43 and the use of technological supports (eg, the Internet, tailored print materials, and automated phone prompts).17,44,45
An evaluation of the strengths and limitations of different delivery models, such as provider-delivered versus computer-delivered physical activity counseling would also make a significant contribution to the physical activity intervention literature. In the areas of smoking and dietary change, many successful interventions have been developed in which the physician provides brief advice only and then nonphysician providers or other office staff deliver the majority of the intervention46,47 Given time constraints on physicians in most medical settings, the use of nonphysician delivery models warrants further investigation in the area of physical activity.
Finally, cost-effective ways to deliver physical activity counseling to older patients and to conduct follow-up are needed.
Recommendations for clinical practice
Health care providers can implement moderately effective brief physical activity interventions following brief training during the course of routine health care delivery. We have 3 specific evidence-based recommendations. These recommendations primarily address how to achieve short-term changes in patient physical activity. The issue of long-term maintenance is more complex.
* An initial focus on physical activity only, as opposed to multiple risk factors, is recommended, although maintenance may be enhanced when supported over time by other risk factor interventions.
* Tailored interventions and written materials enhance success rates. The most basic written materials are standard pamphlets on physical activity available from organizations such as the American Heart Association and the American Lung Association. More effective print materials based on this review and a growing literature40 would be tailored to patient characteristics and preferences. Although such tailored print materials are not commonly available, health care providers might consider a 1-page physical activity prescription form. Such a form would indicate the physical activity goal, the specific behaviors the patient should engage in, the primary barriers the patient anticipates will get in the way of the goal and suggestions for overcoming the barriers, and identification of sources of support for physical activity.
* Physical activity counseling can be successfully implemented by a variety of health care team members. The person who delivers the intervention should be whomever is most likely to do so consistently, given time, training, and interest.
SEARCH STRATEGIES: We searched MEDLINE (1980 to 1998), psychological abstracts, ERIC and HealthStar databases, the Web site for The Journal of Family Practice, bibliographies of selected studies, and previous reviews for relevant articles. The search was limited to the English language. Three experts in the field of physical activity were contacted for leads on unpublished trials.
SELECTION CRITERIA: Inclusion criteria were: randomized controlled trial or quasiexperimental study using a comparison group, intervention delivered or initiated in a primary care setting, and reported results on at least 1 measure of physical activity. Studies that focused solely on patients with cardiovascular disease were excluded.
MAIN RESULTS: Primary care-based physical activity counseling is moderately effective in the short term, although there is considerable variability across studies. Studies in which the interventions were tailored to participant characteristics and which offered written materials to patients produced stronger results. Unlike many types of health promotion, the reach of primary care-based physical activity interventions is high. Questions remain about the consistency of implementation and long-term maintenance of outcomes.
CONCLUSIONS: Despite the need for further research, enough is known to recommend integration of key strategies of physical activity counseling into routine practice. We recommend incorporating these strategies into primary care and prioritizing them for further research.
What strategies are practical and effective to use in family practice settings to enhance levels of patient physical activity?
Regular physical activity is essential for disease prevention and health promotion.1-4 Even moderate levels of physical activity are associated with a reduced incidence of a variety of chronic conditions.1,3-7 National recommendations for physical activity from the American College of Sports Medicine and the Centers for Disease Control and Prevention state that all adults should accumulate 30 minutes a day of moderate intensity activity on 5 or more days per week. However, only 32% of US adults achieve that level.8
The National Health Promotion and Disease Prevention Objectives in Healthy People 20109-11 and the US Preventive Services Task Force12 recommend that physicians and other health care providers counsel their patients to be physically active, yet the majority of physicians do not. Two recent studies of older adults13,14 found that 48% and 36% reported having received advice regarding physical activity from their physicians. Barriers to such counseling include skepticism about its efficacy, competing demands, lack of time, lack of reimbursement, and the lack of standardized assessment and procedure protocols that would make counseling feasible to for busy office settings.15-17
We reviewed the literature on primary care-based physical activity interventions and offer evidence-based recommendations for incorporating them into practice. Our review differs from previous reviews of physical activity interventions in health care settings18-20 because we evaluate studies using the RE-AIM framework which was developed for evaluating the public health impact of health promotion activities. We also included a methodologic quality rating for each study and reported or calculated effect sizes and odds ratios where possible.
The RE-AIM Framework
The RE-AIM framework21 focuses attention on a real-world effectiveness perspective22 compatible with the realities of medical office treatment. There are 5 dimensions to the RE-AIM model that combine to determine the overall public health impact of an intervention. Two factors operate at the level of individual patients: Reach—the percentage and representativeness of patients who are willing to participate in a given procedure, and Efficacy—the impact of an intervention on behavioral, biologic, quality-of-life, and economic outcomes. There are also 2 less often studied but equally important dimensions that have an impact on a medical office or health care system: Adoption—the percentage and representativeness of settings that are willing to adopt an office innovation, and Implementation—the extent to which an intervention is delivered as intended. The fifth dimension, Maintenance, operates at both the individual and system levels. At the individual level, maintenance refers to the extent to which effects are stable long after an intervention is delivered. For this review, we adopted a minimum of a 1-year follow-up as criteria for demonstrating maintenance. At the systems level, maintenance refers to institutionalization of policies and practices such that they become routine.
These 5 factors interact to determine the overall population-based impact of a program. One implication of this model is that an intervention that generally does poorly on 1 or 2 dimensions (ie, fails to reach many patients or is implemented inconsistently) will have low overall public health impact. The RE-AIM evaluation framework was adopted because it relates more to practice-oriented research and real world concerns than other evaluation models and because it places equal emphasis on external validity (generalization) and internal validity, which is helpful in determining how relevant a study is for family practice.
Methods
We conducted electronic MEDLINE searches for the years 1980 to 1998 using Grateful Med and the National Library of Medicine’s PubMed search engines. We also performed computerized searches of psychological abstracts, ERIC and HealthStar databases, and of The Journal of Family Practice’s World WideWeb site (www.jfampract.com). The keywords we used for searching included: physical activity and randomized controlled trials, physical activity counseling and primary care or medical office, exercise interventions and primary care or medical office, and physical activity and health promotion. We limited the search to the English language. We searched bibliographies of selected studies and previous reviews for relevant articles. Finally, we contacted 3 experts in the field of physical activity for leads on unpublished trials. Although we attempted to be inclusive, our literature search may have been biased by the English language-only criterion and by the use of a single searcher.
The following inclusion criteria were used: randomized controlled trial or quasiexperimental study having a comparison group, intervention delivered or initiated in a primary care setting, and reported results on at least 1 measure of physical activity. We excluded studies that focused solely on patients with cardiovascular disease because they are generally considered to comprise a separate body of literature and not be representative of the larger population of patients seen in primary care.18 We identified 48 articles and retained 15 for the final review. The 33 not selected were not controlled trials, focused on a specific medical condition, or did not take place in a primary care setting. We contacted the authors of the 11 studies from which it was not possible to calculate effect size or odds ratio. Three authors responded with information adequate to perform the calculations.
The methodology rating we used was based on the RE-AIM model. RE-AIM was used rather than alternatives, such as the CONSORT criteria, because of its more balanced emphasis on internal and external validity and its relevance for practice-oriented research. The 6 criteria for rating methodology (and the possible points for each) are as follows:
Study design (0-3). One point was assigned for randomized studies. Two points were given to studies that used a placebo, equal contact control, or alternative treatment. One point was given for use of a comparison condition that controlled for a component of the intervention, usual care, or advice-only control groups.
Analyses (0-1). One point was given for analyses that controlled for potential confounding variables or adjusted for baseline physical activity.
Dependent variable (0-1). One point was given to studies that used previously validated outcome measures or that reported the reliability and validity of the physical activity measure.
Reach (0-1). One point was given to studies reporting on the percentage or representativeness of participants.
Implementation (0-2). One point was given to studies for which the intervention was conducted by clinic staff. An additional point was given if the quality of the intervention implementation was reported.
Attrition (0-2). One point was given if attrition was reported. An additional point was given if the rate of attrition was 10% or less or if an intention-to-treat analysis or imputation of missing data was used.
Results
The Table shows descriptive information and short- and long-term outcomes for the 15 studies we reviewed. It includes the methodology rating, sample size, study design and the physical activity intervention (ie, length and content), outcome variables and length of follow-up, and outcomes presented in terms of effect sizes for continuous variables and odds ratios for dichotomous variables for both short-term (less than 12 months) and long-term (12 months or longer) outcomes. Interrater reliability between the 2 independent raters on the methodology score was rho = 0.85, and disagreements were resolved by conference with the senior author.
Outcomes
Of the 10 studies reporting 0- to 11-month post- intervention outcomes, 7 reported statistically significant physical activity outcomes. Effect sizes ranged from 0.003 to 0.26 and odds ratios from 1.04 to 3.73 (median = 1.88). Of the 7 studies reporting postintervention outcomes at 12 months or longer, 3 reported statistically significant outcomes. The only study among these from which an effect size could be calculated reported d = 0.09, and follow-up odds ratios ranged from 0.09 to 1.39 (median = 1.25). Unfortunately, it is not possible to summarize these outcomes in a straightforward manner, such as percentage of patients who changed from being sedentary to meeting the new guidelines for regular moderate physical activity or number needed to treat. This is because rather than using standard measures of physical activity, the authors of most of the studies developed or selected their own continuous (for which we have presented mean effect size) or dichotomous physical activity measures (for which we have presented odds ratios). What can be said is that well-controlled physical activity studies have generally produced moderate short-term improvements, but these results are often less encouraging at long-term follow-up.
Methodology Rating
The methodology rating scores for the studies we included ranged from 4 to 9, with the majority receiving a score of 6 or 7 on the scale of 0 to 10. Overall, the study designs were strong, with the vast majority being randomized trials that studied relatively large samples, employed appropriate analyses, and reported on attrition rates. The methodologic areas in which studies were downgraded most often were for not reporting implementation results and failing to employ intention-to-treat analyses or imputation procedures to address attrition issues. There was not a strong relationship between methodologic quality and intervention effectiveness. Five of the 10 studies with significant effects had methodology ratings of 7 or higher.
Sample
Study sample sizes ranged from small (N = 63) to large (N = 6124). Although all but one study included both men and women, the percentage of women was greater in most studies. All studies focused on adults, with an age range of 18 years to 75 years and older. Four studies included only adults 50 years and older, and none demonstrated significant short-term results, though one achieved long-term outcomes. Seven studies included only sedentary patients, although the definition of sedentary was not consistent across studies; the other 8 studies included patients with a range of or unspecified baseline physical activity levels.
In 12 studies, the bulk of the physical activity (or multiple risk factor) intervention was delivered during a routine primary care visit. In the other 3, a portion of the intervention took place in classes or groups outside of the primary care setting. The intervention was delivered by physicians in 9 studies, by nurses in 3 studies, by a physician and a health educator in 2 studies, and by public health students in 1 study. No clear relationship emerged between type of interventionist and effectiveness. Of the 7 studies with significant short-term effects, 4 had physicians deliver the intervention, one used nurse delivery, and 2 used delivery by a physician and health educator combination. Of the 3 studies with significant long-term effects, one was delivered by physicians, one by nurses, and one by public health students.
Study Design and Physical Activity Intervention
Nine studies employed a randomized controlled trial. In 8 studies, physical activity was the sole focus of the intervention; in 7 studies, the physical activity intervention was part of a multiple risk factor intervention, including behaviors such as smoking, diet, alcohol and seat belt use. Physical activity-only interventions faired better in the short term than multiple risk factor interventions; 6 of the 7 studies with significant short-term effects focused on physical activity only. In contrast, all 3 of the studies with significant long-term effects were multiple risk factor interventions. Walking was the most common activity recommendation.
The length of the initial provider-delivered intervention varied greatly—from 3 to 10 minutes of physical activity counseling in 7 studies to 15 to 120 minutes of multiple risk factor counseling in 3 studies. Brief counseling may be as effective as more lengthy counseling, since 5 of the 7 studies with significant short-term effects involved 3- to 10-minute counseling sessions. The majority of the studies provided at least some details about the amount of provider training regarding the physical activity (or multiple risk factor) intervention, which ranged from 15 minutes of individual training and the provision of tip sheets to 2-hour workshops.
Ten of the 15 studies involved interventions that were tailored to patient characteristics, such as readiness to exercise, baseline levels of physical activity, or physical activity preferences. Tailoring seemed to affect short-term physical activity outcomes, with 6 of the 7 studies with significant short-term effects using some form of tailored intervention. Of the 3 studies with significant long-term effects, only one involved a tailored intervention. Eleven of 15 studies used written materials that ranged from brief physical activity tip sheets to more extensive physical activity manuals. The use of written materials also seemed to have an impact on short-term outcomes, with 6 of 7 studies with short-term effects offering them to their patients. Two of the 3 studies with significant long-term effects used written materials to accompany the intervention. Six of the 15 studies included some form of follow-up support for the patient—3 offered an additional physician office visit, one used a phone call from the health educator, and 3 used tailored mailed physical activity pamphlets. There was no clear advantage of the use of follow-up support; only 3 of the 10 studies with significant effects used them.
Theory-Based Interventions
Seven of the 15 studies described the theoretical basis of the physical activity intervention employed. All explicitly theory-based physical activity interventions used at least some of, if not all, the components of social-cognitive theory23,24 or self-management/behavior change interventions (eg, assessment and feedback, goal-setting, identification of barriers to change, personalized problem solving, reinforcement, and supportive follow-up).24-27 Four studies employed a transtheoretical model or “stages of change” theoretical perspective.28,29 Three of these 4 studies failed to find significant short-term effects.19,30,31 Overall, theory-based physical activity interventions were not any more effective than those not based on explicit theories of behavior change; only 4 of the 10 studies with significant effects were based on explicit theories of behavior change.
Key Physical Activity Outcome and Length of Follow-Up
Studies used a wide range of physical activity outcome variables, with varying definitions of sedentary lifestyle, regular and moderate activity, and vigorous exercise. All studies relied on patient self-reports of physical activity, with one study using activity monitors and one including a measure of physical fitness (VO2 max) to corroborate self-report. In both studies, the significant intervention effect on the self-reported physical activity outcomes was corroborated by this additional activity monitor or fitness data. Length of follow-up ranged from 4 weeks to 4 years, with 7 studies reporting follow-ups of 12 months or longer. Few studies reported on outcomes other than physical activity or the multiple risk factors associated with the intervention. Three studies assessed body mass index, one assessed cholesterol and blood pressure, 2 assessed quality of life, and one reported on cost-effectiveness.
Although the majority of studies did not specifically report on subject attrition, it was possible to calculate attrition rates for all studies. Attrition was moderately high and ranged from 1% to 44% (median = 18%) at follow-ups of fewer than 12 months, and 20% to 56% (median = 41%) at longer-term follow-ups. Only 4 of the 11 studies with attrition rates of 15% or higher used intention-to-treat analyses or imputation methods to address attrition. Those patients who dropped out tended to be less educated, more likely to smoke, and in poorer health.
RE-AIM Criteria
Eleven of 15 studies reported on the percentage of the eligible population who agreed to participate (Reach), ranging from 35% to 100% (median = 74%), but only 3 of those described whether enrolled subjects were representative of the larger population from which the sample was drawn. In all 3 studies, participants differed from nonparticipants on demographic variables such as sex and smoking status, raising concerns about the representativeness of the samples studied. In contrast, only 3 studies reported on the percentage of eligible primary care settings and providers who agreed to participate in the study (Adoption).
The authors of 12 studies reported at least some data on intervention implementation. The most common implementation measures were whether patients attended a visit or whether physicians delivered advice. Implementation for these relatively crude indices was variable (range = 30%-100%) but generally high, especially for delivery of advice (80%-100%).
In terms of efficacy, of the 10 studies reporting 0- to 11-month postintervention outcomes, 7 reported statistically significant physical activity outcomes. Regarding maintenance, of the 7 studies reporting 12-month or longer postintervention outcomes, 3 reported statistically significant outcomes. As in other health behavior change areas, it appears challenging to maintain initial treatment effects. Two of the 3 studies reporting both short-term and long-term results32,33 found significant efficacy results at initial follow-ups, but in all 3 studies results were no longer significant at later follow-up.
Discussion
Brief primary care-based physical activity interventions are effective in producing moderate short-term improvements in self-reported physical activity levels. Of the 10 studies reporting short-term outcomes, 7 reported statistically significant results. A more detailed evaluation of intervention characteristics revealed a number of factors associated with successful outcomes, including brief interventions (of 3 to 10 minutes) that focused on physical activity only, were tailored to patient characteristics and preferences, and included supplemental written materials. In contrast, longer interventions focusing on multiple risk factors that did not include written patient materials did not achieve significant short-term results for physical activity. Short-term improvements on physical activity were observed across all types of interventionists, including physicians, nurses, and combinations of physicians and health educators.
There are some intervention components that seem logical that we cannot recommend. Unlike the literature in other health behavior change areas,34,35 the use of follow-up supports after the initial intervention did not increase the likelihood of positive short-term results. Another surprise was that theory-based interventions did not appear more successful than those not explicitly theory based; specifically, interventions using the transtheoretical model were not effective. None of the studies that focused solely on older adults (those aged 50 years and older) achieved positive short-term results, indicating that this is an area in need of further attention. The issue of long-term effectiveness is difficult to evaluate. Only 7 studies reported long-term outcomes, and only 3 of those achieved significant results.
RE-AIM Conclusions
Compared with the general health promotion literature, more studies reported on the Reach and representativeness of participants than is typically observed,36-38 and these results were encouraging. Primary care-based physical activity interventions are an effective means of reaching a large segment of sedentary adults, although the representativeness of study samples remains unclear. Men, smokers, and older adults appear less likely to participate in physical activity interventions.
Our review revealed a solid body of research documenting the Efficacy of primary care-based physical activity interventions. There has been far less research on Adoption of primary care-based physical activity interventions. Only 3 studies reported on adoption, and none of these addressed whether the participating providers or practices were representative. Much more research is needed on intervention and clinic characteristics associated with adoption. The representativeness of the settings and clinicians participating in health behavior change research is equally important as the representativeness of the patients studied.
Approximately 75% of the studies reported on Implementation. Brief physician counseling can be consistently implemented. Other intervention components, such as repeat visits and follow-up counseling, appear more difficult to deliver consistently.
Although brief, primary care-based interventions appear efficacious in producing short-term changes in physical activity, Maintenance remains difficult. This is true not only for physical activity, but also for the majority of health promotion/disease management behaviors prescribed by physicians (eg, medication taking, smoking cessation, dietary change).34,39
Directions for Future Research
Maintenance of short-term intervention gains in physical activity is a key issue for future research. A National Heart, Lung, and Blood Institute-sponsored collaborative trial (the Activity Counseling Trial) is underway to address this issue.41 Other ways to affect maintenance that warrant further evaluation include assisting patients in using available community physical activity resources26,42,43 and the use of technological supports (eg, the Internet, tailored print materials, and automated phone prompts).17,44,45
An evaluation of the strengths and limitations of different delivery models, such as provider-delivered versus computer-delivered physical activity counseling would also make a significant contribution to the physical activity intervention literature. In the areas of smoking and dietary change, many successful interventions have been developed in which the physician provides brief advice only and then nonphysician providers or other office staff deliver the majority of the intervention46,47 Given time constraints on physicians in most medical settings, the use of nonphysician delivery models warrants further investigation in the area of physical activity.
Finally, cost-effective ways to deliver physical activity counseling to older patients and to conduct follow-up are needed.
Recommendations for clinical practice
Health care providers can implement moderately effective brief physical activity interventions following brief training during the course of routine health care delivery. We have 3 specific evidence-based recommendations. These recommendations primarily address how to achieve short-term changes in patient physical activity. The issue of long-term maintenance is more complex.
* An initial focus on physical activity only, as opposed to multiple risk factors, is recommended, although maintenance may be enhanced when supported over time by other risk factor interventions.
* Tailored interventions and written materials enhance success rates. The most basic written materials are standard pamphlets on physical activity available from organizations such as the American Heart Association and the American Lung Association. More effective print materials based on this review and a growing literature40 would be tailored to patient characteristics and preferences. Although such tailored print materials are not commonly available, health care providers might consider a 1-page physical activity prescription form. Such a form would indicate the physical activity goal, the specific behaviors the patient should engage in, the primary barriers the patient anticipates will get in the way of the goal and suggestions for overcoming the barriers, and identification of sources of support for physical activity.
* Physical activity counseling can be successfully implemented by a variety of health care team members. The person who delivers the intervention should be whomever is most likely to do so consistently, given time, training, and interest.
1. US Department of Health and Human Services. Physical activity and health: a report of the Surgeon General Executive Summary. Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, The President’s Council on Physical Fitness and Sports. Atlanta, Ga: US Government Printing Office; 1996.
2. National Institutes of Health. Physical activity and cardiovascular health. JAMA 1996;76:241-6.
3. Harris SS, Caspersen CJ, DeFriese GH, et al. Physical activity counseling for healthy adults as a primary preventive intervention in the clinical setting: report for the US Preventive Services Task Force. JAMA 1989;261:3590-8.
4. Pate RR, Pratt M, Blair SN, et al. Physical activity and public health: a recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 1995;273:402-7.
5. Paffenbarger RS, Hyde RT, Wing AL, Hsieh C-C. Physical activity, all-cause mortality, and longevity of college alumni. N Eng J Med 1986;314:605-13.
6. US Department of Health and Human Services. Health promotion and older adults. Prev Rep 1989;1-5.
7. Clark NM, Becker MH, Janz NK, Lorig K, Rakowski W, Anderson L. Self-management of chronic disease by older adults. J Aging Health 1991;3:3-27.
8. Jones DA, Ainsworth BE, Croft JB, Macera CA, Lloyd EE, Yusuf HR. Moderate leisure-time physical activity: Who is meeting the public health recommendations? A national cross-sectional study. Arch Fam Med 1998;7:285-9.
9. US Department of Health and Human Services Office Public Health and Science. Healthy people 2010 objectives: draft for public comment. 1998.
10. Pinto BM, Goldstein MG, Marcus BH. Activity counseling by primary care physicians. Prev Med 1998;27:506-13.
11. US Department of Health and Human Services. Promoting health/preventing disease year 2000 health objectives for the nation. 1990.
12. US Preventive Services Task Force. Guide to clinical preventive services: an assessment of the effectiveness of 169 interventions. Baltimore, Md: Williams & Wilkins, 1989.
13. Damush TM, Stewart AL, Millls K, King AC, Ritter PL. Prevalence and correlates of physician recommendations to older adults to exercise. Ann Behav Med 1998;20:S194.-
14. Eakin EG, Glasgow RE. Recruitment of managed care Medicare patients for a physical activity study. Am J Health Promo 1997;12:98.-
15. Beaven DW, Scott RS. The organization of diabetes care. In: Alberti KGMM, Krall LP, eds. The diabetes annual 2. New York, NY: Elsevier; 1986;39-48.
16. Orlandi MA. Promoting health and preventing disease in health care settings: an analysis of barriers. Prev Med 1987;16:119-30.
17. Glasgow RE, McKay HG, Boles SM, Vogt TV. Interactive technology, behavioral science, and health care: progress, pitfalls, and promise. J Fam Pract 1999;48:464-70.
18. Simons-Morton DG, Calfas KJ, Oldenburg B, Burton NW. Effects of interventions in health care settings on physical activity or cardiorespiratory fitness. Am J Prev Med 1998;15:413-30.
19. Goldstein MG, Pinto BM, Marcus BH, et al. Physician-based physical activity counseling for middle-aged and older adults: a randomized trial. Ann Behav Med In press.
20. Eaton CB, Menard LM. A systematic review of physical activity promotion in primary care office settings. Br J Sports Med 1998;32:11-6.
21. Glasgow RE, Vogt TM, Boles SM. Evaluating the public health impact of health promotion interventions: the RE-AIM framework. Am J Public Health In press.
22. Flay BR. Efficacy and effectiveness trials (and other phases of research) in the development of health promotion programs. Prev Med 1986;15:451-74.
23. Bandura A. Social foundations of thought and action: a social cognitive theory. Englewood Cliffs, NJ: Prentice Hall; 1986.
24. Bandura A. Self-efficacy: the exercise of control. New York, NY: W.H. Freeman, 1997.
25. Strecher VJ, Seijts GH, Kok GJ, et al. Goal setting as a strategy for health behavior change. Health Educ Q 1995;22:190-200.
26. Glasgow RE, Eakin EG. Medical office-based interventions. In: Snoek FJ, Skinner CS, eds. Psychological aspects of diabetes care. In press.
27. Wagner EH, Austin B, Von Korff M. Improving outcomes in chronic illness. Manag Care Q 1996;4:12-25.
28. Prochaska JO, Velicer WF, Rossi JS, et al. Stages of change and decisional balance for 12 problem behaviors. Health Psychol 1994;13:39-46.
29. Marcus BH, Rakowski W, Rossi JS. Assessing motivational readiness and decision-making for exercise. Health Psychol 1992;11:2457-61.
30. Marcus BH, Goldstein MG, Jette AM. Training physicians to conduct physical activity counseling. Prev Med 1997;26:382-8.
31. Graham-Clarke P, Oldenburg B. The effectiveness of a general-practice-based physical activity intervention on patient physical activity status. Behavior Change 1994;11:132-44.
32. Bull FC, Jamrozik K. Advice on exercise from a family physician can help sedentary patients to become active. Am J Prev Med 1998;15:85-94.
33. Reid LR, Morgan RW. Exercise prescription: a clinical trial. Am J Public Health 1979;69:591-5.
34. Gochman DS, Gochman DS, eds. Handbook of health behavior research II. New York, NY: Plenum Press; 1997.
35. Glasgow RE, Eakin EG. Issues in diabetes self-management. In: Shumaker SA, Schron EB, Ockene JK, McBee WL, eds. The handbook of health behavior change. 2nd ed. New York, NY: Springer Publishing Company, 1998;435-61.
36. Glasgow RE, Eakin EG, Toobert DJ. How generalizable are the results of diabetes self-management research? The impact of participation and attrition. Diabetes Educ 1996;22:573-85.
37. Glasgow RE, McCaul KD, Fisher KJ. Participation in worksite health promotion: a critique of the literature and recommendations for future practice. Health Educ Q 1993;20:391-408.
38. Sorensen G, Emmons KM, Hunt MK, Johnston D. Implications of the results of the community intervention trials. Annu Rev Public Health 1998;19:379-416.
39. Orleans CT. Treating nicotine dependence in medical settings: a stepped-care model. In: Orleans CT, Slade J, eds. Nicotine addiction: principles and management. New York, NY: Oxford University Press, 1993;145-62.
40. de Vries H, Brug J. Computer-tailored interventions motivating people to adopt health promoting behaviors: Introduction to a new approach. Patient Educ Couns 1999;36:99-105.
41. King AC, Sallis JF, Dunn AL, et al. Overview of the Activity Counseling Trial (ACT) intervention for promoting physical activity in primary health care settings. Med Sci Sports Exerc 1998;30:1086-96.
42. Stewart AL, Sepsis PG, King AC, McLelland BY, Roitz K, Ritter PL. Evaluation of CHAMPS, a physical activity promotion program for older adults. Ann Behav Med 1997;19:353-61.
43. Sallis JF, Owen N. Physical activity and behavioral medicine. Turner JR, ed. Thousand Oaks, Calif: Sage Publications; 1999.
44. Piette JD, McPhee SJ, Weinberger M, Mah CA, Kraemer FB. Can patients with diabetes use automated telephone disease management calls effectively? In press.
45. Piette JD, Mah CA. The feasibility of automated voice messaging as an adjunct to outpatient diabetes care. Diabetes Care 1997;20:15-21.
46. Hollis JF, Lichtenstein E, Vogt TM, Stevens VJ, Biglan A. Nurse-assisted counseling for smokers in primary care. Ann Intern Med 1993;118:521-5.
47. Glasgow RE, La Chance P, Toobert DJ, Brown J, Hampson SE, Riddle MC. Long-term effects and costs of brief behavioral dietary intervention for patients with diabetes delivered from the medical office. Patient Educ Couns 1997;32:175-84.
48. Elder JP, Wright BL. Longitudinal effects of preventive services on health behaviors among an elderly cohort. Am J Prev Med 1995;11:354-8.
49. Jette AM, Lachman M, Giorgetti MM, et al. Exercise—it’s never too late: the Strong-for-Life Program. AM J Public Health 1999;89:66-72.
50. King AC, Oka R, Pruitt L, Philips W. Developing optimal exercise regimens for seniors: a clinical trial. Ann Behav Med 1997;19:S056.-
51. Pereira MA, FitzGerald SJ, Gregg EW, et al. A collection of physical activity questionnaires for health-related research. Med Sci Sports Exer 1997;29:S1-205.
1. US Department of Health and Human Services. Physical activity and health: a report of the Surgeon General Executive Summary. Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, The President’s Council on Physical Fitness and Sports. Atlanta, Ga: US Government Printing Office; 1996.
2. National Institutes of Health. Physical activity and cardiovascular health. JAMA 1996;76:241-6.
3. Harris SS, Caspersen CJ, DeFriese GH, et al. Physical activity counseling for healthy adults as a primary preventive intervention in the clinical setting: report for the US Preventive Services Task Force. JAMA 1989;261:3590-8.
4. Pate RR, Pratt M, Blair SN, et al. Physical activity and public health: a recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 1995;273:402-7.
5. Paffenbarger RS, Hyde RT, Wing AL, Hsieh C-C. Physical activity, all-cause mortality, and longevity of college alumni. N Eng J Med 1986;314:605-13.
6. US Department of Health and Human Services. Health promotion and older adults. Prev Rep 1989;1-5.
7. Clark NM, Becker MH, Janz NK, Lorig K, Rakowski W, Anderson L. Self-management of chronic disease by older adults. J Aging Health 1991;3:3-27.
8. Jones DA, Ainsworth BE, Croft JB, Macera CA, Lloyd EE, Yusuf HR. Moderate leisure-time physical activity: Who is meeting the public health recommendations? A national cross-sectional study. Arch Fam Med 1998;7:285-9.
9. US Department of Health and Human Services Office Public Health and Science. Healthy people 2010 objectives: draft for public comment. 1998.
10. Pinto BM, Goldstein MG, Marcus BH. Activity counseling by primary care physicians. Prev Med 1998;27:506-13.
11. US Department of Health and Human Services. Promoting health/preventing disease year 2000 health objectives for the nation. 1990.
12. US Preventive Services Task Force. Guide to clinical preventive services: an assessment of the effectiveness of 169 interventions. Baltimore, Md: Williams & Wilkins, 1989.
13. Damush TM, Stewart AL, Millls K, King AC, Ritter PL. Prevalence and correlates of physician recommendations to older adults to exercise. Ann Behav Med 1998;20:S194.-
14. Eakin EG, Glasgow RE. Recruitment of managed care Medicare patients for a physical activity study. Am J Health Promo 1997;12:98.-
15. Beaven DW, Scott RS. The organization of diabetes care. In: Alberti KGMM, Krall LP, eds. The diabetes annual 2. New York, NY: Elsevier; 1986;39-48.
16. Orlandi MA. Promoting health and preventing disease in health care settings: an analysis of barriers. Prev Med 1987;16:119-30.
17. Glasgow RE, McKay HG, Boles SM, Vogt TV. Interactive technology, behavioral science, and health care: progress, pitfalls, and promise. J Fam Pract 1999;48:464-70.
18. Simons-Morton DG, Calfas KJ, Oldenburg B, Burton NW. Effects of interventions in health care settings on physical activity or cardiorespiratory fitness. Am J Prev Med 1998;15:413-30.
19. Goldstein MG, Pinto BM, Marcus BH, et al. Physician-based physical activity counseling for middle-aged and older adults: a randomized trial. Ann Behav Med In press.
20. Eaton CB, Menard LM. A systematic review of physical activity promotion in primary care office settings. Br J Sports Med 1998;32:11-6.
21. Glasgow RE, Vogt TM, Boles SM. Evaluating the public health impact of health promotion interventions: the RE-AIM framework. Am J Public Health In press.
22. Flay BR. Efficacy and effectiveness trials (and other phases of research) in the development of health promotion programs. Prev Med 1986;15:451-74.
23. Bandura A. Social foundations of thought and action: a social cognitive theory. Englewood Cliffs, NJ: Prentice Hall; 1986.
24. Bandura A. Self-efficacy: the exercise of control. New York, NY: W.H. Freeman, 1997.
25. Strecher VJ, Seijts GH, Kok GJ, et al. Goal setting as a strategy for health behavior change. Health Educ Q 1995;22:190-200.
26. Glasgow RE, Eakin EG. Medical office-based interventions. In: Snoek FJ, Skinner CS, eds. Psychological aspects of diabetes care. In press.
27. Wagner EH, Austin B, Von Korff M. Improving outcomes in chronic illness. Manag Care Q 1996;4:12-25.
28. Prochaska JO, Velicer WF, Rossi JS, et al. Stages of change and decisional balance for 12 problem behaviors. Health Psychol 1994;13:39-46.
29. Marcus BH, Rakowski W, Rossi JS. Assessing motivational readiness and decision-making for exercise. Health Psychol 1992;11:2457-61.
30. Marcus BH, Goldstein MG, Jette AM. Training physicians to conduct physical activity counseling. Prev Med 1997;26:382-8.
31. Graham-Clarke P, Oldenburg B. The effectiveness of a general-practice-based physical activity intervention on patient physical activity status. Behavior Change 1994;11:132-44.
32. Bull FC, Jamrozik K. Advice on exercise from a family physician can help sedentary patients to become active. Am J Prev Med 1998;15:85-94.
33. Reid LR, Morgan RW. Exercise prescription: a clinical trial. Am J Public Health 1979;69:591-5.
34. Gochman DS, Gochman DS, eds. Handbook of health behavior research II. New York, NY: Plenum Press; 1997.
35. Glasgow RE, Eakin EG. Issues in diabetes self-management. In: Shumaker SA, Schron EB, Ockene JK, McBee WL, eds. The handbook of health behavior change. 2nd ed. New York, NY: Springer Publishing Company, 1998;435-61.
36. Glasgow RE, Eakin EG, Toobert DJ. How generalizable are the results of diabetes self-management research? The impact of participation and attrition. Diabetes Educ 1996;22:573-85.
37. Glasgow RE, McCaul KD, Fisher KJ. Participation in worksite health promotion: a critique of the literature and recommendations for future practice. Health Educ Q 1993;20:391-408.
38. Sorensen G, Emmons KM, Hunt MK, Johnston D. Implications of the results of the community intervention trials. Annu Rev Public Health 1998;19:379-416.
39. Orleans CT. Treating nicotine dependence in medical settings: a stepped-care model. In: Orleans CT, Slade J, eds. Nicotine addiction: principles and management. New York, NY: Oxford University Press, 1993;145-62.
40. de Vries H, Brug J. Computer-tailored interventions motivating people to adopt health promoting behaviors: Introduction to a new approach. Patient Educ Couns 1999;36:99-105.
41. King AC, Sallis JF, Dunn AL, et al. Overview of the Activity Counseling Trial (ACT) intervention for promoting physical activity in primary health care settings. Med Sci Sports Exerc 1998;30:1086-96.
42. Stewart AL, Sepsis PG, King AC, McLelland BY, Roitz K, Ritter PL. Evaluation of CHAMPS, a physical activity promotion program for older adults. Ann Behav Med 1997;19:353-61.
43. Sallis JF, Owen N. Physical activity and behavioral medicine. Turner JR, ed. Thousand Oaks, Calif: Sage Publications; 1999.
44. Piette JD, McPhee SJ, Weinberger M, Mah CA, Kraemer FB. Can patients with diabetes use automated telephone disease management calls effectively? In press.
45. Piette JD, Mah CA. The feasibility of automated voice messaging as an adjunct to outpatient diabetes care. Diabetes Care 1997;20:15-21.
46. Hollis JF, Lichtenstein E, Vogt TM, Stevens VJ, Biglan A. Nurse-assisted counseling for smokers in primary care. Ann Intern Med 1993;118:521-5.
47. Glasgow RE, La Chance P, Toobert DJ, Brown J, Hampson SE, Riddle MC. Long-term effects and costs of brief behavioral dietary intervention for patients with diabetes delivered from the medical office. Patient Educ Couns 1997;32:175-84.
48. Elder JP, Wright BL. Longitudinal effects of preventive services on health behaviors among an elderly cohort. Am J Prev Med 1995;11:354-8.
49. Jette AM, Lachman M, Giorgetti MM, et al. Exercise—it’s never too late: the Strong-for-Life Program. AM J Public Health 1999;89:66-72.
50. King AC, Oka R, Pruitt L, Philips W. Developing optimal exercise regimens for seniors: a clinical trial. Ann Behav Med 1997;19:S056.-
51. Pereira MA, FitzGerald SJ, Gregg EW, et al. A collection of physical activity questionnaires for health-related research. Med Sci Sports Exer 1997;29:S1-205.