Review of Primary Care-Based Physical Activity Intervention Studies

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 resources^26,42,43 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 intervention^46,47 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.