Effectiveness of physical activity advice and prescription by physicians in routine primary care: a cluster randomized trial.

ABSTRACT

BACKGROUND: Physical activity promotion is a priority, but contribution of physicians' interventions is unclear. The effectiveness of the PEPAF ("Experimental Program for Physical Activity Promotion"), which was implemented exclusively by physicians in routine primary care from October 2003 to December 2004, was assessed. METHODS: Fifty-six Spanish family physicians were randomized to either the intervention (n = 29) or standard care (n = 27) arm of the trial. The physicians recruited 4317 physically inactive patients (2248 for intervention and 2069 for control protocols) from a systematic sample after assessing their physical activity in routine practice. Intervention physicians provided advice to all patients and a physical activity prescription to the subgroup attending an additional appointment (30%). The main outcome measure was the change in physical activity measured by blinded nurses using the 7-Day Physical Activity Recall. Secondary outcomes included cardiorespiratory fitness and health-related quality of life. RESULTS: At 6 months, intervention patients increased physical activity more than controls (adjusted difference, 18 min/wk [95% confidence interval, 6-31 min/wk]; metabolic equivalent tasks x hours per week, 1.3 [95% CI, 0.4-2.2]). The proportion of the population achieving minimal physical activity recommendations was 3.9% higher in the intervention group (1.2%-6.9%; number needed to treat, 26). No differences were found in secondary outcomes. The effect of intervention was positively modified in subjects older than 50 years (P < or = .01) and in the prescription subgroup (P < .001). CONCLUSIONS: Family physicians were effective for increasing physical activity of primary care patients. Overall clinical effect was small but relevant for population public health. Within the intervention program, clinically relevant effects were seen in patients receiving a physical activity prescription. Trial Registration clinicaltrials.gov Identifier NCT00131079.