Contingency Management for Methamphetamine Abstinence and HIV Post-Exposure Prophylaxis in Men Who Have Sex With Men

At the baseline, all eligible participants underwent informed consent; completed baseline assessments; received rapid HIV testing; provided specimens for syphilis, gonorrhea and chlamydia testing; and received a medical examination. Those who reported a high-risk sexual or drug exposure episode with an HIV-positive or serostatus-unknown source within the preceding 72 hours immediately initiated postexposure prophylaxis. All other participants received a 4-day ''starter pack'' of Truvada to be initiated only in the case of a future high-risk exposure to HIV. All participants began the voucher-based CM intervention upon study entry. For the initial 8 weeks of study conduct, participants presented to the study site three times weekly for a urine drug screen for methamphetamine metabolites. Participants who provided urine samples that were negative for methamphetamine metabolites earned vouchers, which escalated in value for successive negative urine samples. A participant with a missing sample or a sample positive for methamphetamine metabolites did not earn vouchers. Accrued vouchers were never forfeited and could be redeemed at any time during the study for gift certificates or goods or services that promote healthy, pro-social behaviors; vouchers could not be redeemed for cash.