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Factors associated with program effectiveness in the implementation of a sexual risk reduction intervention for female sex workers across Mexico: Results from a randomized trial.



The overall aim of this paper is to examine effectiveness of an evidence-based intervention in community settings, and the factors associated with effectiveness. Limited research in the area of HIV prevention has focused on evaluating intervention program effectiveness in real-world settings.


We implemented an efficacious theory-based sexual risk reduction intervention for female sex workers (FSW) called Mujer Segura across 13 different clinics in 13 sites across Mexico. The overall design was a cluster randomized Type I design simultaneously testing intervention program effectiveness with an observational study of implementation factors. We aimed to examine the effectiveness of Mujer Segura at reducing HIV/STI incidence among FSW participants at each site, and to examine the client-, provider-, organization-, and structure-related factors associated with program effectiveness.


We found lower HIV/STI incidence density in the intervention relative to the control group in 5 sites we labeled as "program effective sites," but not in 8 sites we labeled as "program ineffective sites." Using generalized estimating equations controlling for site and computed mean difference effect sizes, we examined statistically and practically significant differences, respectively, between the two groups of sites along various client-, provider-, organization-, and structure-related characteristics. Results indicated that client-level HIV/AIDS related knowledge, and proficiency and engagement in the organizational social context were associated with program effectiveness.


Enormous resources are required to systematically and adequately test the role of multilevel factors on program effectiveness. We successfully implemented Mujer Segura in 13 sites in Mexico. Results suggest that other measures may need to be included in future implementation studies than the ones included here. We were able to point to a few specific factors that should be targeted to increase effectiveness of similar evidence-based programs in low- and other middle-income countries like Mexico.

Trial registration NCT01465607.

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