Increasing recognition of the importance of behavior for health and the rapidly escalating cost of healthcare conspire to create a strong need for widespread dissemination of interventions to promote health and prevent disease. Traditional public health and clinical interventions cannot fully address this need because of resource constraints, limited access to hard-to-reach populations, and other factors. These conditions have created the impetus for innovative approaches to health education and promotion.
Benefits of computer-delivered interventions (CDIs) include uniformity of intervention delivery, 24-hour access, and the ability to tailor an intervention to an individual (Budman et al. 2003
). Although the first two benefits address the delivery of CDIs, the last feature promises to enhance intervention efficacy. Health behavior change models, such as the information, motivation, and behavioral skills model (IMB) and the transtheoretical model, suggest that tailoring intervention content enhances behavioral change (Fisher and Fisher 1992
; Prochaska and DiClemente 1982
). Tailoring can increase both the efficacy of an intervention as well as user satisfaction and completion of the program by allowing for a more engaging personalized experience (Ryan and Lauver 2002
). Computerized tailoring allows for an individualized experience based on the user’s responses to material in the program. The combined elements of tailoring and open access to CDIs serve important functions. They allow for intervention delivery that is engaging, accessible, and faithfully implemented (Kaufmann 2007
). In addition, CDIs can be delivered to individuals living in remote locations (Schopp et al. 2006
) or those with physical limitations. CDIs may address antecedents of a health behavior (e.g., knowledge or attitudes) as well as directly addressing the behavior itself. If efficacious, CDIs may also be cost-saving.
Because CDIs vary on many dimensions (e.g., use of tailoring, dose, interactivity, theoretical basis, target behavior and population), a systematic review to identify the components of effective CDIs and their relative impact on behaviors is needed. Previous reviews of CDIs have either been descriptive (Evers et al. 2003
) or limited to a single health behavior (e.g., smoking; Walters et al. 2006
). A meta-analytic review comparing web-based versus print applications of health interventions showed positive, though widely varying, benefits (Wantland et al. 2004
). These reviews suggest that web-based CDIs can be efficacious (Wofford et al. 2005
This meta-analytic review goes beyond the previous reviews by comparing CDIs across health domains and providing a more comprehensive picture of their benefits. We examine the effects of CDIs on a variety of health constructs and behaviors. Psychosocial, behavioral, and educational CDIs were located through a systematic review of the literature. We examine the extent to which these interventions affect (a) knowledge, (b) hypothesized determinants or mediators of health-behavior change (e.g., attitudes, intentions, norms, self-efficacy), (c) behavioral outcomes (physical activity, nutrition, tobacco use, substance use, safer sexual behavior, and overall health-maintenance), and (d) objective behavioral outcomes (weight loss, diabetes control, binging/purging); we also examine whether sample and intervention characteristics moderate intervention efficacy.