AN ANALYSIS OF THE PROCESS OF HUMAN-IMMUNODEFICIENCY-VIRUS SEXUAL RISK BEHAVIOR-CHANGE

Few studies have tried to identify the process of risk behavior change . In this paper, we present a method for the analysis of the process o f risk behavior change; the methodology involves using time series dat a to form transition probability matrices. We apply the method to huma n immunodeficiency virus (HIV) sexual risk behavioral data from a coho rt of gay men in Amsterdam. We determine the process of risk behavior change in this cohort, and we demonstrate that it is not possible to d educe the process simply from an examination of the static pattern. Ou r results imply that the risk behavior change that is observed in this cohort may be viewed as a homogeneous one-step Markovian process. Thi s process of risk behavior change has implications for the long-term p rediction of HIV seroconversion rates and for the design and evaluatio n of HIV behavioral intervention studies and vaccine trials. Our resul ts also have implications for the interpretation of relapse behavior.