Related Experiment Video
Updated: Feb 19, 2026

A Modified Trier Social Stress Test for Vulnerable Mexican American Adolescents
Published on: July 10, 2017
Punto Seguro: A Randomized Controlled Pilot Using Conditional Economic Incentives to Reduce Sexually Transmitted
Omar Galárraga1, Sandra G Sosa-Rubí2, Caroline Kuo1
1Brown University School of Public Health, Providence, RI, USA.
Abstract:
Randomized controlled pilot evaluated effect of conditional economic incentives (CEIs) on number of sex partners, condom use, and incident sexually transmitted infections (STIs) among male sex workers in Mexico City. Incentives were contingent on testing free of new curable STIs and/or clinic attendance. We assessed outcomes for n = 227 participants at 6 and 12 months (during active phase with incentives), and then at 18 months (with incentives removed). We used intention-to-treat and inverse probability weighting for the analysis. During active phase, CEIs increased clinic visits (10-13 percentage points) and increased condom use (10-15 percentage points) for CEI groups relative to controls. The effect on condom use was not sustained once CEIs were removed. CEIs did not have an effect on number of partners or incident STIs. Conditional incentives for male sex workers can increase linkage to care and retention and reduce some HIV/STI risks such as condomless sex, while incentives are in place.
Related Concept Videos
Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and...
Sexually Transmitted Infections
Randomized Experiments
Simple randomization
Simple...
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Community Based Intervention
Foundations of Community Mental Health Programs
Central to the success of community-based interventions is the...
Bioequivalence Experimental Study Designs: Completely Randomized and Randomized Block Designs

