Behavior change techniques in digital physical activity interventions for breast cancer survivors: a systematic review

Common behavior change techniques in digital physical activity interventions for survivors of breast cancer include goal setting, social support, and self-monitoring. However, many potentially effective behavior change techniques for physical activity were used sparingly and should be considered for incorporation in future interventions for this population. Given the broad benefits of physical activity (PA) but low PA levels among breast cancer survivors (i.e., women who have received a breast cancer diagnosis), innovative and evidence-based techniques are needed to motivate and support exercise. This study systematically reviews the use of behavior change techniques (BCTs) in digital PA interventions for breast cancer survivors. Studies were retrieved from five electronic databases and were included if they (i) sampled exclusively female breast cancer survivors aged >18 years, (ii) involved a digital intervention with the primary purpose of increasing PA, (iii) included a BCT component, (iv) used a randomized or quasi-randomized design, and (v) were published from January 2000 to May 2022. Two coders independently extracted data. Twenty primary studies met the inclusion criteria and were included in this review. All interventions used at least one BCT (mean 4 +/- 1, range 2-13); self-monitoring (85%) and goal setting (79%) were the most common BCTs. Twelve of 20 (60%) studies reported improvements in PA behavior in the intervention vs. control group, and self-monitoring and goal setting were the most commonly used BCTs in these studies. Of the 93 total BCTs, 66 were not used in any interventions in the review, including critical constructs for PA behavior change (e.g., biofeedback). BCTs, important facilitators of PA behavior change, are being underutilized in digital PA interventions for breast cancer survivors. Future research should incorporate more diverse BCTs to explore if they can add to the effectiveness of digital interventions for this population. Lay Summary Physical activity (PA) has many benefits, yet PA levels are low among breast cancer survivors (i.e., women who have received a breast cancer diagnosis). This study reviews the use of behavior change techniques (BCTs) in digital PA interventions for breast cancer survivors. BCTs are evidence-based and are important for encouraging changes in health behaviors, such as PA. Twenty studies were included in this review. All interventions used at least one BCT (mean 4 +/- 1, range 2-13); self-monitoring (85%) and goal setting (79%) were the most common BCTs. Twelve of 20 (60%) studies reported improvements in PA, and self-monitoring and goal setting were the most commonly used BCTs in these studies. Of the 93 total BCTs, 66 were not used in any interventions in the review. This finding reveals that many BCTs, which are important influencers of behavior change, are often not being used in digital PA interventions for breast cancer survivors. BCTs such as biofeedback (e.g., providing information on heart rate during exercise) and practical social support (e.g., virtual exercise coaching), could be helpful. Future research should include more diverse BCTs to explore if they can add to the usefulness of digital interventions for this population.