A systematic review of e-health interventions for physical activity: an analysis of study design, intervention characteristics, and outcomes.

OBJECTIVE This systematic literature review of e-health interventions targeting physical activity (PA) from January 2006 to November 2010 provides an updated and critical picture of the state of e-health as a facilitator for PA interventions. MATERIALS AND METHODS A systematic search yielded 31 articles that fit into the inclusion/exclusion criteria, which were analyzed in terms of study design quality, intervention characteristics, and support for e-health in PA interventions. RESULTS The included articles met most of the study design criteria, but many did not isolate e-health technologies or use power analyses to calculate sample sizes. The interventions reflected a variety of technologies, audiences, and methods, and showed consistent use of theoretical frameworks to guide the interventions. Results regarding support for e-health's effectiveness in PA interventions were mixed and cannot provide definite conclusions. Only seven studies used pure control groups, and of those, four demonstrated support for e-health but the others showed no significant differences. The majority of studies using comparison groups showed no significant differences between conditions. No notable patterns emerged among the studies that did show support for e-health. CONCLUSIONS Future research should utilize more rigorous methods that allow for better comparison across studies, such as power analyses, pure control groups, and objective PA measurements, which could lead to more definitive results regarding e-health's effectiveness for PA interventions.