Men Who Have Sex With Men-Identification Criteria and Characteristics From the National Health and Nutrition Examination Survey, 1999 to 2014.

Objectives: This study aimed to provide identification criteria for men who have sex with men (MSM), estimate the prevalence of MSM behavior, and compare sociodemographics and sexually transmitted disease risk behaviors between non-MSM and MSM groups using data from a nationally representative, population-based survey.
Methods: Using data from men aged 18 to 59 years who took part in the National Health and Nutrition Examination Survey (NHANES), 1999 to 2014, detailed criteria were developed to estimate MSM behavior-at least one lifetime same-sex partner (MSM-ever), at least one same-sex partner in the past 12 months (MSM-current), and at least one lifetime and zero same-sex partners in the past 12 months (MSM-past).
Results: The estimated prevalence of MSM-ever was 5.5%-of these, 52.4% were MSM-current and 47.1% were MSM-past. Furthermore, MSM-ever are a nonhomogenous subpopulation, for example, 70.4% of MSM-current identified as homosexual and 71.2% of MSM-past identified as heterosexual (P < 0.001).
Conclusions: The prevalence of MSM behavior identified here is similar to other published estimates. This is also the first article, to our knowledge, to use National Health and Nutrition Examination Survey data to compare MSM by 2 recall periods (recent vs. lifetime) of last same-sex sexual behavior.