Abstract

Cost-effectiveness of a brief behavioral intervention to reduce HIV/STI incidence and promote condom use among female sex workers in the Mexico-US border region

J.L. Burgos¹, J.A. Gaebler¹, S.A. Strathdee¹, R. Lozada², H. Staines-Orozco³, T.L. Patterson<sup>4,5

1</sup>University of California San Diego, Division of Global Public Health, La Jolla, United States, ²Baja California State Public Health Service, HIV/AIDS Prevention Program, Tijuana, Mexico, ³Faculty of Medicine, Autonomous University of Ciudad Juarez, Chihuahua, Mexico, ⁴University of California San Diego, Department of Psychiatry, La Jolla, United States, ⁵Veterans Administration San Diego Medical Center, La Jolla, United States

Background. Previous research demonstrated efficacy of a brief behavioral intervention to reduce incidence of
HIV and sexually transmitted infections (STIs) among female sex workers (FSWs) in Tijuana
and Ciudad Juarez, Mexico, cities on Mexico's border with the US. We assessed the cost-effectiveness of this intervention.
Methods. A life-time Markov model was developed to estimate HIV cases prevented, changes in quality-adjusted life expectancy (QALE), and costs per additional quality-adjusted life year gained (QALY), comparing no intervention to a once-only and annual intervention. Future costs and health benefits were discounted annually at 3%. One-way and multivariate sensitivity analyses evaluated model robustness.
Results. For a hypothetical 1,000 FSWs receiving the once-only intervention, there were 33 HIV cases prevented and 5.7 months of QALE gained compared to no intervention. The additional cost per QALY gained was US$183(95% CI: $164-$206). For FSWs receiving the intervention annually, there were 29 additional HIV cases prevented and 4.5 additional months of QALE compared to the once-only intervention. The additional cost per QALY was US$1,075 (95%CI: US$931-$1,259). When highly active antiretroviral therapy (HAART) was included in the model, the annual intervention strategy resulted in net savings of US$1,592 (95% CI: $1,260-$1,929) per QALY gained and dominated both once-only and no intervention strategies. Even when considering clinical benefits from HAART, ignoring added costs, the cost per QALY gained remained below three times the Mexican GDP per capita, and below established cost-effectiveness thresholds. Results were robust across extensive sensitivity analyses.
Conclusions. This brief behavioral intervention was shown to be highly cost-effective among FSWs in two Mexico-US border cities, furthermore our analyses shows the potential for cost-savings from averted HAART expenditures from this intervention. Therefore, resources should be allocated to identifying barriers and facilitators to large scale implementation of this and similar cost-effective behavioral interventions in similar resource constrained settings.