Underreporting in HIV-related high-risk behaviors: comparing the results of multiple data collection methods in a behavioral survey of prisoners in Iran.

We explored the potentials of using three indirect methods including crosswise, proxy respondent method, and network scale-up (NSU) in comparison to direct questioning in collecting sensitive and socially stigmatized HIV-related risk behaviors information from prisoners (N=265). Participants reported more sexual contact in prison for their friends than they did for themselves (10.6% vs. 3.8% in men, 13.7% vs. 0% in women). In men, NSU provided lower estimates than direct questioning, while in women NSU estimates were higher. Different data collection methods provide different estimates, and collectively offer a more comprehensive picture of HIV-related risk behaviors in prisons.