Fig. 1

A directed acyclic graph (DAG) depicting our hypothesized conception of the system under investigation. We sought to estimate the independent contribution of age, marital status, education, occupation (proxy for socioeconomic status), pregnancy, and HIV Infection status to the prevalence of HPV infection in Ugandan women. Exposure to HPV-infected sexual partners and immune status were not directly measured by our study and hence could not be evaluated. The DAG was used to guide which variables to control for when assessing the independent contribution of the various constructs