(2) factors associated with each one separately. Thai MSM aged 18 years or older and living in Bangkok were eligible to participate in the BMCS. At each follow-up visit, participants were asked to report their sexual and drug behaviors in the previous 4 months. We conducted a longitudinal analysis using generalized estimating equations logistic regression that included 1,569 MSM who were enrolled from 2006 to 2010 and contributed at least one follow-up visit. For each four-month visit increase, we found a 2, 1, and 1 % decrease in odds for reported UAI, recreational drug use, and multiple sexual partners, respectively.