A systematic review and meta-analysis of social cognitive theory-based physical activity and/or nutrition behavior change interventions for cancer survivors

Abstract Purpose Little is known about how to improve and create sustainable lifestyle behaviors of cancer survivors. Interventions based on social cognitive theory (SCT) have shown promise.This reviewexamined theeffectofSCT-basedphysical activity and nutrition interventions that target cancer survivors and identified factors associated with their efficacy. Methods A systematic search of seven databases identified randomized controlled trials that (i) targeted adult cancer survivors (any point from diagnosis); (ii) reported a primary outcomeofphysicalactivity,diet,orweightmanagement;and (iii) included an SCT-based intervention targeting physical activity or diet. Qualitative synthesis and meta-analysis were conducted. Theoretical constructs and interventioncharacteristics were examined to identify factors associated with intervention efficacy. Results Eighteen studies (reported in 33 publications) met review inclusion criteria. Meta-analysis (n=12) revealed a significant intervention effect for physical activity (standardized mean difference (SMD)=0.33;