Abstract
Multiple-behaviour change interventions (MBC) may have greater impact on health and wellbeing than single-behaviour interventions, especially when behaviours are related to higher-level goals such as improved survivorship experiences following cancer. Based on social cognitive theory, initial success in one behavioural domain may lead to increased perceived self-efficacy and foster subsequent mastery and motivation for change in another domain. MBC may be ideal for informing behavioural counselling, as many cancer survivors accumulate multiple behavioural risk factors (i.e., not meeting physical activity [PA] guidelines and poor diet). A systematic review of randomized controlled trials (N = 25 analyzed) was conducted using electronic databases to identify the MBC design approaches – sequential (one behaviour after the other) or simultaneous – and examined effectiveness on diet and PA in survivors. Post-intervention treatment effect sizes (standardized mean difference [SMD]) were calculated for fruit and vegetable consumption (F&V), fat intake (%fat), diet quality (DQ), and PA. Studies simultaneously targeting behaviours (n = 23), SMD ranges: 0.14 to 1.66 (F&V), -2.29 to 0.28 (%fat) and 0.04 to 0.92 (DQ), and -0.43 to 1.22 (PA). Sequential interventions (n = 2), SMD ranges: 0.21 to 0.22 (F&V), -0.41 to -0.07 (%fat) and 0.36 to 0.38 (DQ) and 0.11 to 0.24 (PA). Given study heterogeneity and low number of sequential studies, further research is needed to determine the most effective approach for improving health behaviours among cancer survivors. With more definitive information on intervention approach, behavioural counselling strategies can be tailored to the approach for maximal health benefit.
