Multiple risk behaviour interventions:Meta-analyses of RCTs

Context: Systematic review, meta-analysis, and meta-regression of the effectiveness of multiple risk behaviour interventions. Evidence acquisition: Six electronic databases including MEDLINE, EMBASE and PsycINFO searched to August 2016. Study selection: RCTs of non-pharmacological interventions in general adult populations. Studies targeting specific at risk groups (such as people screened for cardiovascular risk factors, or obesity) were excluded. Study appraisal: Studies were screened independently. Study characteristics and outcomes were extracted and risk of bias assessed by one researcher and checked by another. The Behaviour Change Wheel and Oxford Implementation Index were used to code intervention content and context. Evidence synthesis: Random effects meta-analyses were conducted. Sixty-nine trials involving 73,873 individuals were included. Interventions mainly comprised education and skills training and were associated with modest improvements in most risk behaviours: increased fruit and vegetable intake (0.31 portions; 95% CI 0.17 to 0.45), and physical activity (SMD 0.25; 95% CI 0.13 to 0.38) and reduced fat intake (SMD -0.24; 95% CI -0.36 to -0.12). Although reductions in smoking were found (OR 0.78; 95% CI 0.68 to 0.90), they appeared to be negatively associated with improvement in other behaviours (such as diet and physical activity). Preliminary evidence suggests that sequentially changing smoking alongside other risk behaviours was more effective than simultaneous change. But most studies assessed simultaneous rather than sequential change in risk behaviours therefore comparisons are sparse. Follow-up period and intervention characteristics impacted on effectiveness for some outcomes. Conclusions: Interventions comprising education (e.g. providing information about behaviours associated with health risks) and skills training (e.g. teaching skills that equip participants to engage in less risky behaviour) and targeting multiple risk behaviours concurrently are associated with small changes in diet and physical activity. Although on average smoking was reduced, it appeared changes in smoking were negatively associated with changes in other behaviours suggesting it may not be optimal to target smoking simultaneously with other risk behaviours. Systematic Review registration: PROSPERO number CRD42013005248