摘要：OBJECTIVES: As a means of enhancing public health efforts to control sexual transmission of human immunodeficiency virus (HIV), methods were developed to report on risk behavior in a manner that is comparable and widely interpretable. METHODS: An elementary sexual behavior risk index (the vaginal episode equivalent index) that is in accord with some of the essential knowledge about sexual transmission of HIV is described, and a multivariate ordinal risk (MOR) method that can be used to improve such risk indices is introduced. RESULTS: An example shows that these approaches are applicable to observational studies of seroconversion. CONCLUSIONS: The MOR represents a powerful new tool to develop valid comparable measures of sexual risk behavior and, thereby, to advance HIV prevention research.
