Objectives HIV studies and risk assessments among men who have sex with men (MSM) frequently use self-reported STI history as a proxy for true STI history. The objective of our study was to assess the validity of self-reported STI history through comparison with laboratory-confirmed biomedical results.

Methods Data were analysed for MSM attending the Los Angeles LGBT Center (the Center) from August 2011 to July 2015. We identified 10 529 unique MSM who received testing for chlamydia, gonorrhoea and/or syphilis and had a later visit in which they self-reported their STI history to a clinic counsellor during a risk assessment.

Results MSM who had an STI in the past year self-reported their STI history with 51%–56% accuracy, and MSM who had an STI more than a year ago self-reported their STI history with 65%–72% accuracy. Among MSM with any positive STIs at the Center, black/African-American and Hispanic MSM were more likely to inaccurately self-report their positive results for gonorrhoea (adjusted OR (aOR): 1.48, 95% CI 1.09 to 2.01; aOR: 1.39, 95% CI 1.14 to 1.70). Additionally, HIV-positive MSM were more likely to inaccurately self-report their positive results for gonorrhoea (aOR: 1.63, 95% CI 1.22 to 2.18) and/or syphilis (aOR: 2.19, 95% CI 1.08 to 4.47).

Conclusions This is the first study that attempts to evaluate the validity of self-reported STI history among MSM. We found that self-reported STI history may not be an appropriate proxy for true STI history in certain settings and minority populations. Clinical guidelines and research studies that rely on self-reported STI history will need to modify their recommendations in light of the limited validity of these data.