Reporting sexual risk behavior for HIV: a practical risk index and a method for improving risk indices.

Abstract

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. 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. An example shows that these approaches are applicable to observational studies of seroconversion. The MOR represents a powerful new tool to develop valid comparable measures of sexual risk behavior and, thereby, to advance HIV prevention research.