Efficacy of text messaging-based interventions for health promotion: a meta-analysis.

This meta-analysis investigated the efficacy of text messaging-based health promotion interventions. Nineteen randomized controlled trials conducted in 13 countries met inclusion criteria and were coded on a variety of participant, intervention, and methodological moderators. Meta-analytic procedures were used to compute and aggregate effect sizes. The overall weighted mean effect size representing the impact of these interventions on health outcomes was d = .329 (95% CI = .274, .385; p < .001). This effect size was statistically heterogeneous (Q18 = 55.60, p < .001, I(2) = 67.62), and several variables significantly moderated the effects of interventions. Smoking cessation and physical activity interventions were more successful than interventions targeting other health outcomes. Message tailoring and personalization were significantly associated with greater intervention efficacy. No significant differences were found between text-only interventions and interventions that included texting plus other components. Interventions that used an individualized or decreasing frequency of messages over the course of the intervention were more successful than interventions that used a fixed message frequency. We discuss implications of these results for health promotion interventions that use text messaging.