Impact and economic evaluations of a combination prevention programme for men who have sex with men in Mexico

Abstract

Background: Despite the high-profile support for combination prevention programmes (CPPs) since 2008, there is little rigorous evidence on their impact and cost-effectiveness. In 2010, Mexico received funds from the Global Fund to implement a series of behavioural, biomedical, and structural interventions over 3 years targeted to men who have sex with men. The aims of the study were to estimate the impact of the programme across a range of outcomes and cost-effectiveness. Methods: A quasi-experiment was designed before the implementation of the CPP, in which 24 cities were randomly selected for impact evaluation and 12 pairs of cities were matched. In practice, though, implementation of the programme was staggered over 1 year. Therefore, we used two different approaches to estimate impact: a difference-in-difference estimation comparing both groups and a dose–response approach using time exposure to the programme at the city level. Findings: Results from the difference-in-difference estimation showed modest impact on condom use. However, the dose–response findings revealed a 7.5% increase in HIV testing per additional year exposed to the programme, relative to baseline coverage; an increase in awareness of HIV status among HIV-positive individuals of 6.6%; a 6.4% increase in HIV-positive individuals on treatment; and an 8% reduction in the perception of stigma/discrimination from healthcare personnel. The cost per person not exposed to an untreated HIV-positive individual was gauged to be US$400. Conclusions: The study provides evidence of the effectiveness and cost of a CPP along the HIV treatment cascade: access to HIV tests, awareness of HIV status, and antiretroviral therapy initiation.