Context: Existing evidence shows that text message interventions can produce short-term health behavior change. However, understanding is limited regarding intervention characteristics moderating this effect or the long-term effectiveness of text message interventions on behavior change after contact stops.
Evidence acquisition: MEDLINE, PubMed Central, ERIC, PsycINFO, and Web of Science were searched for articles published between April 2008 and December 2014 that evaluated an intervention targeting preventive health behaviors, delivered primarily by text message.
Evidence synthesis: Intervention development and design characteristics and research outcomes were evaluated for 51 studies. Thirty-five studies were included in a meta-analysis (conducted in 2015) examining overall effect size and moderators of effect size. The overall pooled effect of interventions was d=0.24 (95% CI=0.16, 0.32, p<0.001) using outcome data collected most proximal to intervention cessation. Seven studies collected data following a no-intervention maintenance period and showed a small but significant pooled maintenance effect (d=0.17, 95% CI=0.03, 0.31, p=0.017, k=7). Few variables significantly moderated intervention efficacy. Interventions that did not use a theoretic basis, used supplementary intervention components, and had a duration of 6-12 months were most effective. The specific behavior being targeted was not associated with differences in efficacy nor was tailoring, targeting, or personalization of text message content.
Conclusions: Text message interventions are capable of producing positive change in preventive health behaviors. Preliminary evidence indicates that these effects can be maintained after the intervention stops. The moderator analysis findings are at odds with previous research, suggesting a need to examine moderators at the behavior-specific level.
Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.