Theory-Based Text-Messaging to Reduce Methamphetamine Use and HIV Sexual Risk Behaviors Among Men Who Have Sex with Men: Automated Unidirectional Delivery Outperforms Bidirectional Peer Interactive Delivery.

Project Tech Support2 was a randomized controlled trial that tested three methods of text message delivery for reducing methamphetamine use and HIV risks among MSM. From March 2014 to January 2016, 286 methamphetamine-using MSM were randomized into: (1) interactive text conversations with Peer Health Educators, plus five-times-a-day automated theory-based messages, plus a weekly self-monitoring text-message assessment (TXT-PHE; n = 94); or, (2) the daily automated messages and weekly self-monitoring assessment (TXT-Auto; n = 99); or, (3) weekly self-monitoring assessment only (AO; n = 93). All three conditions demonstrated reductions in methamphetamine use (coef. = - 0.10), sex on methamphetamine (coef. = - 0.09), and condomless anal intercourse (CAI) with casual male partners (coef. = - 0.06). Only participants in TXT-PHE and TEXT-Auto also reduced CAI with main male partners (coef = - 0.19; coef. = - 0.16), and only TEXT-Auto participants reduced CAI with anonymous male partners (coef. = - 0.05). Additionally, both theory-based text-messaging interventions achieved sustained reductions in five of the six outcomes through 9 months. Overall, automated delivery outperformed peer-delivered messaging.