Clinical research into LGBT populations

For public health departments and providers to plan appropriate services for a population, especially a vulnerable one, it is essential to have reliable data on population demographics and health status. Until recently, many of the research studies conducted in the LGBT community were community-based studies using nonprobability sampling techniques.[2, 3] The studies, often using convenience sampling, were prone to selection bias. For example, studies conducted at bars and clubs were known to have overestimated certain health issues such as the prevalence of tobacco and substance use. In addition, the use of small nonprobability samples to examine the health of LGBT communities may not be representative of the population's racial, ethnic, and socioeconomic composition.

To adequately describe the LGBT population and assess health indicators and risks, it is therefore necessary to conduct well-designed population-based studies. An additional issue with investigating the LGBT community is that no single question adequately captures the diversity and complexity of the lives of LGBT individuals. Self-disclosed sexual orientation has been shown to not predict sexual behavior. A person who identifies as lesbian or gay may still have sexual relations with members of the opposite sex, for example.

The first national survey on sexual behaviors among U.S. adults examined sexual orientation, attraction, and identity. This study highlighted the difficulty with defining sexual identity in this population. Findings showed that 9.9 percent of men and 4.3 percent of women reported having same-sex partners; 7.7 percent of men and 7.5 percent of women have same-sex desire/attraction, however, only 2.8 percent of men and 1.4 percent of women reported self-identification as homosexuals. Homosexual identity was found to be less likely among African Americans, those living in rural areas, and those with less formal education.[4]

Another study of men in New York City found considerable discordance between sexual orientation and behavior with 9.4 percent of straight-identified men reporting sexual intercourse with at least one man in the previous year.[5] The 2002 National Survey of Family Growth (NSFG) also measured indicators of sexual behavior, orientation, and identity among males and females, 15-44 years of age, using face-to-face interviews.

While 4.1 percent of both men and women identified as homosexual or bisexual, a greater number reported same-sex activity: 6 percent of men reported having either oral or anal sexual contact with another man, while 11 percent of women answered yes when asked, "Have you ever had any sexual experience of any kind with another female?" Four percent of women and 2.9 percent of men reported same-sex partners in the last 12 months. The survey also asked about sexual attraction, with 3.2 percent of men and 3.4 percent women reporting same-sex attraction to males and females.[6] Studies conducted among adolescents have also shown a discordance of self-reported sexual orientation and the gender of sexual partners, with lesbian youth more likely than heterosexually identified women to report high-risk sexual activity with opposite-sex partners.[7, 8]