title: Impact and economic evaluations of a combination prevention programme for men who have sex with men in Mexico.
abstract: 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.
  
  
  
  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.
  
  
  
  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 6.3%; a 6.7% increase in HIV-positive individuals on treatment; and a 7% 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.
  
  
  
  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.
authors.affiliation: aCenter for Research on Health SystemsbCenter for Quality Research and Surveys, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, MexicocIndependent consultantdCentro Nacional para la Prevención del VIH y el SIDA, Mexico City, Mexico.*M. Arantxa Colchero and Sergio Bautista-Arredondo share the first authorship to the writing of this article.
authors.forename: M Arantxa
authors.initials: MA
authors.lastname: Colchero
authors.forename: Sergio
authors.initials: S
authors.lastname: Bautista-Arredondo
authors.forename: María A
authors.initials: MA
authors.lastname: Cortés-Ortiz
authors.forename: Martín
authors.initials: M
authors.lastname: Romero-Martinez
authors.forename: Jessica
authors.initials: J
authors.lastname: Salas
authors.forename: Sandra G
authors.initials: SG
authors.lastname: Sosa-Rubí
authors.forename: Patricia
authors.initials: P
authors.lastname: Uribe
mesh_terms: D000293:Adolescent; D000328:Adult; D002947:Cities; D003140:Communicable Disease Control / Q000191:economics* / Q000379:methods*; D003362:Cost-Benefit Analysis; D003627:Data Interpretation, Statistical; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D015658:HIV Infections / Q000517:prevention & control* / Q000635:transmission; D006302:Health Services Research; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008800:Mexico; D055815:Young Adult