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.