Do automated digital health behaviour change interventions have a positive effect on self-efficacy? A systematic review and meta-analysis.

Self-efficacy is an important determinant of health behaviour. Digital interventions are a potentially acceptable and cost-effective way of delivering programmes of health behaviour change at scale. Whether behaviour change interventions work to increase self-efficacy in this context is unknown. This systematic review and meta-analysis sought to identify whether automated digital interventions are associated with positive changes in self-efficacy amongst non-clinical populations for five major health behaviours, and which BCTs are associated with that change. A systematic literature search identified 20 studies (n = 5624) that assessed changes in self-efficacy and were included in a random-effects meta-analysis. Interventions targeted: healthy eating (k = 4), physical activity (k = 9), sexual behaviour (k = 3) and smoking (k = 4). No interventions targeting alcohol use were identified. Overall, interventions had a small, positive effect on self-efficacy (g¯=0.190,CI[0.078;0.303]). The effect of interventions on self-efficacy did not differ as a function of health behaviour type (Q-between = 7.3704, p = .061, df = 3). Inclusion of the BCT 'information about social and environmental consequences' had a small, negative effect on self-efficacy (Δg¯=-0.297,Q=7.072,p=.008). Whilst this review indicates that digital interventions can be used to change self-efficacy, which techniques work best in this context is not clear.