The purpose of this study was to identify factors that influence the effectiveness of interventions in increasing women's use of mammography screening programs. To this end, we conducted a systematic literature review of studies published between 1966 and 1997. In this review, we recorded data about the year and country in which studies were completed, the study design, the methods for measuring screening rates, various sample characteristics, the nature of the intervention, and the resulting screening rates. The PRECEDE model was used as a framework to make distinctions between the various interventions. To synthesize evidence about the baseline screening rates and the effect of interventions on the incidence of mammography screening, we fit random-effects logistic regression models. These models revealed that more recent studies (those conducted from 1990 to 1996) were associated with higher screening rates (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2-3.9). Conversely, those designed to target older women (minimum age, 50-65 years) and those set in clinics exhibited smaller screening rates (OR, 0.6, 95% CI, 0.3-1.0, and OR, 0.5; 95% CI, 0.3-0.8, respectively). The meta-analyses also suggested methodologic issues that must be considered before the relative strength of various interventions can be assessed rigorously.