Estimating the size of key risk groups susceptible to HIV/sexually transmitted diseases (STI) is necessary for establishment of interventions and budget allocation. This study aimed to identify various dimensions of sexual orientation and practices in Israel, and correlate the findings with sexual risk behavior (SRB). It used a random representative sample of the Jewish population aged 18-44 years who completed online questionnaires regarding their self-identified sexual orientation, attraction and practices, and SRB. Concordant heterosexuals were those who self-reported heterosexual identity, were attracted and had sex only with the opposite gender. National estimates regarding prevalence of gay, lesbian, and bisexual men and women were based on the civil census. The sample included 997 men and 1005 women, of whom 11.3 and 15.2 % were attracted to the same-gender, 10.2 and 8.7 % reported lifetime same-gender encounters, while 8.2 and 4.8 % self-identified as gay or bisexual men and lesbian or bisexual women, respectively. The estimated population of self-identified Jewish gay or bisexual men and lesbian or bisexual women aged 18-44 in Israel was 94,176, and 57,671, respectively. SRB was more common among self-identified gays or bisexual men and among discordant heterosexual men and women. Those who reported same-gender sexual practices reported greater SRB than those who only had opposite-gender encounters. Interestingly, SRB among discordant heterosexuals was associated with same-sex behavior rather than attraction. Health practitioners should increase their awareness of sexual diversity among their clientele, and should recognize that risk for HIV/STI may exist among self-identified heterosexuals, who may not disclose their actual sexual attraction or practices.
Keywords: Bisexual; Gay men; Israel; Lesbians; Sexual orientation.