Linearity and nonlinearity in HIV/STI transmission: implications for the evaluation of sexual risk reduction interventions. Eval Rev 2011 Oct;35(5):550-65
Date
12/29/2011Pubmed ID
22201639Pubmed Central ID
PMC4088939DOI
10.1177/0193841X11432196Scopus ID
2-s2.0-84856245302 (requires institutional sign-in at Scopus site) 6 CitationsAbstract
A mathematical model of HIV/sexually transmitted infections (STI) transmission was used to examine how linearity or nonlinearity in the relationship between the number of unprotected sex acts (or the number of sex partners) and the risk of acquiring HIV or a highly infectious STI (such as gonorrhea or chlamydia) affects the utility of sexual behavior change measures as indicators of the effectiveness of HIV/STI risk-reduction interventions. Findings indicate that the risk of acquiring HIV through vaginal intercourse is essentially a linear function of the number of unprotected sex acts and is nearly independent of the number of sex partners. Consequently, the number of unprotected sex acts is an excellent marker for the risk of acquiring HIV through vaginal intercourse, whereas the number of sex partners is largely uninformative. In general, the number of unprotected sex acts is not an adequate marker for the risk of acquiring a highly infectious STI due to the highly nonlinear per act transmission dynamics of these STIs. The number of sex partners is a reasonable indicator of STI risk only under highly circumscribed conditions. A theoretical explanation for this pattern of results is provided. The contrasting extent to which HIV and highly infectious STIs deviate from the linearity assumption that underlies sexual behavior outcome measures has important implications for the use of these measures to assess the effectiveness of HIV/STI risk-reduction interventions.
Author List
Pinkerton SD, Chesson HW, Crosby RA, Layde PMAuthor
Peter M. Layde MS, MD Emeritus Professor in the Emergency Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Disease Transmission, InfectiousHIV Infections
Humans
Linear Models
Program Evaluation
Risk Reduction Behavior
Sexual Behavior
Sexually Transmitted Diseases
