Evaluation of a peer network intervention trial among young methamphetamine users in Chiang Mai, Thailand

Abstract

Since the 1990s, there has been a proliferation of methamphetamine use in Thailand, particularly among young people. Simultaneously, risky sexual behaviors among this population have increased. This study examined the effects of a peer network intervention and a life-skills intervention on methamphetamine and HIV risk behaviors among 18-25 year olds in Chiang Mai, Thailand. Between April 2005 and June 2007, we conducted a randomized behavioral trial to compare the efficacy of a peer educator, network-oriented intervention with a best practice, life-skills curriculum on methamphetamine use, sexual behaviors, and incident sexually transmitted infections (STIs). Follow-up occurred at 3-, 6-, 9-, and 12 months. Both conditions consisted of seven, 2h, small group sessions. Longitudinal analyses of the three outcomes were conducted by fitting repeated measures logistic regression models using generalized estimating equations. Participants (N=983) attended a median of six sessions, with no differences between arms. At each follow-up visit, retention was greater than 85%. Participants were 75% male and were a median of 19 years old. Over time, participants in both conditions showed a significant and dramatic decline in self-reported methamphetamine use (99% at baseline vs. 53% at 12 months, p<0.0001) and significant increase in consistent condom use (32% baseline vs. 44% at 12 months, p<0.0001). Incident STIs were common, with no differences between arms. Chlamydia had the highest incidence rate, 9.85/100 person years and HIV had a low incidence rate of 0.71/100 person years. Among young Thais, we found that a peer educator, network-oriented intervention was associated with reductions in methamphetamine use, increases in condom use, and reductions in incident STIs over 12 months. We also found parallel reductions with the life-skills condition. To our knowledge, this is the first such trial targeting this population. Small group interventions are an effective means of reducing methamphetamine use and sexual risk among Thai youth.

Figure 1

CONSORT Flowchart for Chiang Mai Methamphetamine Intervention Trial

Figure 2. Mean proportion using methamphetamine at baseline and at 3-, 6-, 9- and 12-month follow-ups by intervention assignment.^a

^a Brackets at each time point show 95% confidence intervals for the mean.

Figure 3. Mean proportion always using condoms at baseline and at 3-, 6-, 9- and 12-month follow-ups by intervention assignment. ^a

^a Brackets at each time point show 95% confidence intervals for the mean.