Second, we observed significant increases from 2008 to 2011 in awareness, defined as the percentage of MSM with a positive HIV test result who reported having previously tested positive for HIV, in all demographic subgroups after accounting for possible differences in sample composition due to venue type, sexual identity, outness, and city. It is not possible to fully exclude a methodological change contributing to this finding. However, most aspects of the sampling methodology, including the questionnaire items assessing awareness and prevalence, were unchanged from 2008 to 2011.