Population- and individual-based approaches to the design and analysis of epidemiologic studies of sexually transmitted disease transmission.

Epidemiologic studies of sexually transmitted disease (STD) transmission present a number of unique challenges in design and analysis. These arise both from the social nature of STD transmission and from inherent difficulties in collecting accurate and informative data on exposure and infection. Risk of acquiring an STD depends on both individual-level factors and the behavior and infectiousness of others. Consequently, study designs and analysis methods developed for studying chronic disease risk in individuals or groups may not apply directly. Simple models of STD transmission were used to investigate these issues, focusing on how the interplay between individual- and population-level factors influences design and interpretation of epidemiologic studies, with particular attention to interpretation of common measures of association and to common sources of bias in epidemiologic data. Existing methods for investigating risk factors can be modified such that these issues may be addressed directly.