Promoting physical activity in primary care offers modest benefit
MedWire News: Patients given physical activity counseling in primary care report modest increases in their activity levels 1 year later, shows research published in the BMJ.
The study's authors found no benefit from exercise referral programs, and suggest that healthcare commissioners should opt for primary care-based physical activity promotion schemes, at least until further evidence become available.
The systematic review and meta-analysis included 15 trials and 8745 participants. Eleven of the studies reported positive effects of interventions promoting exercise on self-reported physical activity levels, relative to control or no intervention.
Pooled analysis of 13 trials showed a small-to-medium effect at 12 months; the intervention was favored at an odds ratio of 1.4 by analysis of dichotomized data, and at a standardized mean difference of 0.25 by analysis of continuous data.
In most of the studies, the intervention included written materials and advice or counseling, delivered on multiple occasions either in person or over the telephone by primary care professionals.
Only three trials evaluated referral to exercise programs - one based in a leisure center, one forming part of a community walks program, and another based at an unspecified location. None of these trials reported a benefit from the intervention, and pooled analysis of all three confirmed there was no significant effect on physical activity levels.
Based on the overall findings, the authors estimate that 12 sedentary adults would need to undergo a physical activity intervention for one of them to achieve recommended activity levels, which they say "compares favorably with the estimated number needed to treat of 50-120 for smoking cessation advice."
Gillian Orrow (University of Cambridge, UK) and colleagues also note that, based on the findings of a previous meta-analysis of cohort studies, including almost 1 million people, the activity levels seen in the current study "could reduce mortality by about one fifth."
However, they say such projections should be viewed with caution, given the limitations of self-report measures. The only study that used an objective measurement of physical activity found no benefit from the intervention.
Interestingly, a planned subgroup analysis showed much larger intervention effects in studies where the control group received no intervention at all, rather than a control intervention (either mailed information on the benefits of physical activity, or one-to-one advice to increase physical activity). Furthermore, an exploratory analysis showed that comparator interventions resulted in a similar increase in the proportion of participants meeting international activity recommendations at 12 months (8-47%) to that seen with the test interventions (11-47%).
"These findings suggest that briefer interventions, as used in the comparator groups, might achieve effects that are similar to those of more intensive interventions," comment Orrow and team.
By Caroline Price