A systematic review 1 included 9 RCTs (n=8 015) and 6 quasi-experimental studies (n=17 138).
Of the 10 studies reporting 0- to 11- month post-intervention outcomes, 7 reported statistically significant outcomes. Effect sizes ranged from 0.003 to 0.26 and odds ratios (OR) from 1.04 to 3.73 (median=1.88). Of the 7 studies reporting post-intervention outcomes at 12 or more months, 3 reported statistically significant outcomes. The only study among these from which an effect size could be calculated (d=0.09) reported follow-up ORs ranging from 0.09 to 1.39 (median=1.25).
None of the following parameters were related to effectiveness; interventionist (MD, nurse or student), methodological quality, use of follow-up support, duration of counselling, or whether the intervention was explicitly theory-based. Some between-study differences appeared to be related to effectiveness.
Interventions that focused only on physical activity, and those that were tailored to participants' characteristics, were more effective in the short-term. In contrast, all 3 of the studies with significant long-term effects were multiple risk factor interventions.
Primary/Secondary Keywords