What do we know about brief interventions for physical activity that could be delivered in primary care consultations? A systematic review of reviews.

This systematic review of reviews aims to investigate how brief interventions (BIs) are defined, whether they increase physical activity, which factors influence their effectiveness, who they are effective for, and whether they are feasible and acceptable. We searched CINAHL, Cochrane database of systematic reviews, DARE, HTA database, EMBASE, MEDLINE, PsycINFO, Science Citation Index-Expanded and Social Sciences Citation Index, and Scottish Intercollegiate Guidelines Network from their inception until May 2015 to identify systematic reviews of the effectiveness of BIs aimed at promoting physical activity in adults, reporting a physical activity outcome and at least one BI that could be delivered in a primary care setting. A narrative synthesis was conducted. We identified three specific BI reviews and thirteen general reviews of physical activity interventions that met the inclusion criteria. The BI reviews reported varying definitions of BIs, only one of which specified a maximum duration of 30min. BIs can increase self-reported physical activity in the short term, but there is insufficient evidence about their long-term impact, their impact on objectively measured physical activity, and about the factors that influence their effectiveness, feasibility and acceptability. Current definitions include BIs that are too long for primary care consultations. Practitioners, commissioners and policy makers should be aware of this when interpreting evidence about BIs, and future research should develop and evaluate very brief interventions (of 5min or less) that could be delivered in a primary care consultation.