Where there was a choice of outcome measures, the outcome chosen was the primary behavioural outcome measure specified by the thereby authors, measured by the most objective means (eg, accelerometer data were preferred to

self-reported minutes of physical activity) and adjusted for baseline differences if this had been seen as necessary by the authors. Synthesis of results Data from included studies were meta-analysed in RevMan (V.5.2) using random effect models. For outcomes where a reduction (eg, mean percentage calories in fat) signifies a change in a healthy direction, data were reverse-scored before being entered for meta-analysis. For continuous diet and physical activity outcomes, standardised mean differences (SMD) were calculated using Hedges’ g28 to express the difference between the means for the intervention and control groups in SD units. For dichotomous smoking outcomes, we calculated relative risk (RR) of smoking abstinence and applied the Cochran-Mantel-Haenszel test.29 Where studies had multiple comparisons (several intervention arms or reported outcomes for different behaviours) or were cRCTs, we adjusted participant numbers in line with Cochrane recommendations where possible.30 We conducted meta-analyses for the three behaviours separately at two time points: the most proximal

time point postintervention and the longest follow-up time point where reported. A 95% CI was used and p<0.05 was taken as significant. We assessed variation in effect size between studies using the I2 statistic, with an I2 >50% interpreted as indicating the presence of heterogeneity.27 Following

Cochrane Handbook recommendations,30 we compared independent subgroups of studies differing for two clinically relevant characteristics: interventions targeting women only versus a mixed sex sample, and interventions targeting a single behaviour versus multiple behaviours. Publication bias was assessed by visually inspecting funnel plots. Results Study selection A flow diagram is presented in figure 1. We identified 3939 references from the database search (including the updated search: numbers for this search are given in figure 1) along with the 13 studies identified in Michie et al’s23 review. After removing 1383 duplicates Dacomitinib and excluding 2439 references on the basis of title and abstract screening 130 full texts were screened, of which 120 full texts were successfully retrieved, as 8 articles had no full text and 2 were irretrievable. Full-text screening initially led to the inclusion of 32 studies. Three further studies were identified from title screening reference sections, so that 35 studies with 45 comparisons met inclusion criteria.25 31–71 Figure 1 Study selection flow diagram (italics signify numbers from July 2014 updated search).