pubmed-article:8836026 | pubmed:abstractText | Studies have reported that infection with certain sexually transmitted diseases (STD), such as chancroid, gonorrhea, and genital herpes, enhances the probability of human immunodeficiency virus (HIV) transmission by sexual contact with an infected partner. Epidemiologic studies vary in design from longitudinal to cross-sectional, with varying periods of follow-up or retrospective history of exposure to STD. The major difficulty in assessing the results of past work centers on the validity and precision of widely used measures of association, such as relative risk (RR) and odds ratio (OR), in situations in which common behavior (e.g., different facets of sexual behavior) underpins the acquisition of both the STD cofactor and HIV. | lld:pubmed |