Patterns of sexual risk behavior change among sexually transmitted infection clinic patients.

Effective interventions to reduce sexually transmitted infection (STI) risk behaviors are most potent in the short term and are not uniformly effective for all people. The present study examined patterns of sexual behavior change among 238 men and 104 women who received risk reduction counseling in a public STI clinic and were followed for 9 months with a 1-year retrospective clinic chart abstraction for newly diagnosed STI. A two-stage, multivariate cluster analysis was performed on four risk behavior difference scores (follow-up - baseline) for 1-month, 3-month, 6-month, and 9-month follow-up frequencies of unprotected vaginal and anal intercourse. Cluster analysis identified three profile subgroups: Subgroup 1 had lower levels of risk behavior at all time points; Subgroup 2 had significant reductions in risk over time; and Subgroup 3 demonstrated significant increases in risk over time. Analyses on variables external to the cluster analysis found that the three profile subgroups differed on numbers of sex partners, substance use, sensation seeking, indicators of risk reduction motivation and behavioral skills, and contracting new STI. STI clinic patients with varying profiles of sexual behavior change were, therefore, differentiated by factors relevant to STI interventions.