METHODS
Participants and Data Sources
We analyzed data from 13 cohort studies (10 from the United
States and 3 from Canada) that are included in the North
American AIDS Cohort Collaboration on Research and Design
(NA-ACCORD) for the years 1996–2007. Cohorts were included
if they provided data on anal cancers and sexual orientation.
Study methods for NA-ACCORD have been described elsewhere
[15]. Study protocols were approved by the local institutional
review board for each cohort.
Eleven of the 13 participating cohorts were clinic-based, and
data were obtained from medical records. The remaining 2
participating cohorts (Multicenter AIDS Cohort Study [MACS],
and Women’s Interagency HIV Study [WIHS]) were intervalbased,
and data were obtained as part of a research protocol at
scheduled 6-month study visits. All contributing cohorts
used standardized methods of data collection, and submitted
demographic, treatment, clinical, laboratory, and vital status
data on enrolled HIV-infected individuals. In addition, 3
cohorts (MACS, WIHS, and Kaiser Permanente Northern
California [KPNC]) contributed data on HIV-uninfected
individuals. Because sexual orientation was unknown for
the majority of HIV-uninfected individuals, we were unable
to stratify men in the comparison group by MSM status.