Same-sex sexual behavior and sexual risk behaviors among in-school youth: Findings from a large population-based sample Preeti Pathela1 and Julia A. Schillinger1,2 1 New York City Department of Health and Mental Hygiene, New York 2 Centers for Disease Control and Prevention, Division of Sexually Transmitted Disease Prevention, Atlanta The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the CDC/ATSDR

Background Burden of disease Sexually transmitted infections (STI) disproportionately affect adolescents By 2004, ~40,000 cumulative cases of AIDS in the U.S. were among persons aged 13-24 years New HIV diagnoses among 15-19 year olds ↑ by 20% from 2004 to 2005 The majority of infected male and female adolescents acquire HIV through sex with males A number of bacterial sexually transmitted infections affect adolescents disproportionately and there is a growing concern about HIV/AIDS among U.S. adolescents and young adults The CDC reported approx. 40,000 cumulative cases of AIDS among persons aged 13 to 24 years through 2004. Because the average duration from HIV infection to the development of AIDS is 10 years, most young adults with AIDS were likely infected with HIV as adolescents. The number of new adolescent cases has been on the rise; from 2004 to 2005, new HIV diagnoses among persons aged 15-19 years increased by 20%. Surveillance data on transmission category suggest that the majority of infected male and female adolescents acquire HIV through sex with males. ----------------------------- 33 states with confidential name-based HIV infection reporting: New HIV 2004: 1,012 2005: 1,213

Background The adolescent period Adolescence is a period of sexual experimentation Challenges for adolescents with same-sex partners include: rejection isolation verbal abuse physical violence poor access to confidential health care Studies document higher rates of sexual risk behaviors among youth who report same-sex partners Adolescence is the formative period during which sexual experimentation and identity development take place. In addition to the usual social and personal challenges that accompany adolescence, youth exploring same sex or bisexual sexual experiences may have additional stress resulting from higher levels of rejection, isolation, verbal abuse, physical violence, and poor access to confidential health care. Several studies have documented riskier sexual behaviors among youth with same sex partners that increase their risk for STI, including HIV.

Background Limitations of previous research Convenience samples Survey self-identified gay, lesbian, and bisexual youth Population-based survey data Combine male and female respondents Combine respondents who have: exclusively same-sex partners both male and female sex partners There are limitations to research done to date. Many studies on sexual risk behaviors and related outcomes have relied on convenience samples, and furthermore those studies have categorized respondents based on sexual identity, not sex of partners. Population-based studies have employed varying measures to classify respondents, such as the sex of their partners regardless of whether they have had sexual intercourse. Some of these studies haven’t included gender comparisons, or have combined respondents with bisexual and exclusively same-sex behavior. However persons who are bisexual by self-identification or behavior have been found to differ in sexual risk and outcomes from persons who are exclusively homosexual and should probably not be grouped

Objectives of this analysis Use population-level data: To describe adolescents’ demographics and sexual behaviors, based on sex of partners Focus on adolescents who have had sexual experiences with both males and females To compare self-reported sexual identities for groups reporting sexual activity with members of the same, opposite, and both sexes Our objectives, using population level data, were: To describe adolescents’ demographics and sexual behaviors, based on sex of partners and particularly for an understudied group: adolescents who have had sexual experiences with both males and females. And to characterize sexual identity and sexual behavior, as a means of identifying youth at elevated risk because they are less likely to seek or be identified for prevention information.

Methods The NYC Youth Risk Behavior Survey (YRBS) NYC’s sample within the CDC’s National Youth Risk Behavior Surveillance System assesses trends in health risk behaviors among high school students via in-school, self-administered, anonymous surveys A two-stage cluster sample design accounts for high school, then classroom, and produces a representative sample of NYC public high school students 2005 NYC YRBS: 87 / 91 selected schools participated 8,187 / 11,710 students participated Overall response rate: 68% We included a sample of high school students who completed the 2005 New York City Youth Risk Behavior Survey (YRBS), which is the city’s sample within the CDC’s National Youth Risk Behavior Surveillance System that assesses trends in health risk behaviors via in-school surveys. The NYC YRBS is the largest of 15 state or local youth risk behavior surveys that were conducted in 2005. A two-stage cluster sample design that accounts for high school and classroom produces a representative sample. In 2005, 11,710 students in 91 schools throughout the 5 boroughs of NYC had an equal probability of selection for survey. 87 schools participated, yielding a sample of 8,187 students, and an overall response rate of 68%. -------------------------------------------- School probability of selection proportional to enrollment size 2005 MA YRBS: 68%, Alaska YRBS: 60% (CDC reqs >60% to be representative of state/jurisdiction), Indiana YRBS: 68%, Nevada YRBS: 60%

Methods Pertinent NYC YRBS questions Sexual experience “Have you ever had sexual intercourse?” Yes/no Sex of partner(s) “During your life, with whom have you had sexual contact?” Never had sexual contact, females, males, females & males Sexual identity “Which of the following best describes you?” Heterosexual (straight), gay or lesbian, bisexual, not sure The NYC YRBS included a question asking whether the adolescent had ever had sexual intercourse. Respondents were asked about the sex of persons with whom they had had sexual contact. Response categories were: “I have never had sexual contact,” “Females,” “Males,” and “Females and males.” Neither “intercourse” nor “sexual contact” was specifically defined in these questions. The 2005 NYC YRBS included a question to measure sexual identity: “Which of the following best describes you?” with response categories of “Heterosexual (straight),” “Gay or lesbian,” “Bisexual,” and “Not sure.”

Methods Pertinent NYC YRBS questions Sexual behaviors Age at first intercourse Number of lifetime sex partners Number of sex partners in the last 3 months Condom use at last intercourse Alcohol or drug use at last intercourse History of forced sex (ever) Dating violence during last year Other questions included age at first intercourse, number of lifetime sex partners, number of partners in the last 3 months, whether a condom had been used by the respondent or his or her partner at last intercourse, whether alcohol or drugs had been used before last intercourse, whether there was a history of forced sex, and whether there was incidence of dating violence during the last year.

Methods Analysis Study population: Respondents who reported ever having intercourse & the sex of persons with whom they had sexual contact Behavior groups: Contact with same-sex, opposite-sex, and partners of both sexes For respondents reporting ever having had intercourse, behavior group assignment was based on the sex of persons with whom they reported contact. 3 behavior groups of males and females were constructed: those with only same-sex partners, only opposite-sex partners, and partners of both sexes.

Methods Analysis (cont.) Data weighted to adjust for school and student nonresponse (weighted sample N=116,134) Prevalence estimates for demographic and risk characteristics, by behavior group Distribution of sexual identities among behavior groups SUDAAN software used to obtain appropriate SEs for point estimates Data were weighted to adjust for school and student nonresponse Demographic and selected risk characteristics were described for the behavior subgroups. Separately, the distribution of self-reported sexual identities of respondents in each subgroup was examined.

Results Survey respondents 8118 students 49% male 76% aged 15-17 years Age distributions for males & females similar 57% of males reported having had intercourse 46% of females reported having had intercourse Of 8118 students for whom sex was known, 49% were male. Most respondents were 15-17 years old. The age distributions for males and females were similar. Overall, 57% of males and 46% of females answering the question on sexual intercourse reported that they had had sex. Unweighted data

Results Sex of partners Virtually all sexually active students reported the sex of persons with whom they had sexual contact and were included in this analysis. Among males: 94% had opposite sex, 3% had same-sex, and 3% had both sex partners. Among females: 88% had opposite sex, 3% had only same sex, and 9% had both-sex partners. So, males and females were equally likely to report same-sex only behavior but females were three times more likely than males to report bisexual behavior. Males and females were equally likely to report same-sex only behavior but females were 3x more likely than males to report bisexual behavior (p<.001) Unweighted data

Results Percent males reporting opposite, same, and both-sex partners, by race & ethnicity A high proportion of males in each of 3 racial/ethnic groups (non-Hispanic White, non-Hispanic Black, Hispanic) reported sexual contact only with the opposite sex, however non-Hispanic White males were more likely than other males to report partners of both sexes

Results Male sexual behaviors Sex of partner(s) reported Opposite sex Same sex Both sex N=57,825 N=1,481 N=2,289 % Age at 1st sex <=13 14-15 >=16 53.4* 36.4 10.2 27.6* 64.0* 8.4 77.1 14.9 8.0 No. lifetime partners 1 2-5 >=6 23.1* 49.2* 27.7* 33.2* 50.6* 16.2* 7.4 25.9 66.7 No. ptrs last 3 months >=2 53.9* 46.1* 72.2* 27.8* 17.4 82.6 Statistically significant differences in weighted prevalence estimates (at the .05 alpha level) between persons with partners of both sexes and other groups are denoted by asterisks. Males with male and female partners were more likely than those with opposite sex and with only same sex partners to report an earlier age at first sex, with an average age at sexual debut of 13 years compared to 15 years for the other 2 groups. Males with male and female partners were much more likely to report a greater number of both lifetime and recent sex partners; for males reporting having had sex within the past 3 months, 83% of respondents with both-sex versus 46% with opposite-sex (p=0.0003) and 28% with only same-sex partners (p<0.0001) reported sex with 2 or more partners. * Significant difference compared to group with male & female partners

Results Male sexual behaviors Sex of partner(s) reported Opposite sex Same sex Both sex Reported: N=57,825 N=1,481 N=2,289 % Alcohol/drugs at last sex 17.0* 1.8* 48.1 Condom use at last sex 78.7* 77.0* 28.0 Partner violence (past year) 12.1* 7.4* 32.5 Forced sex (ever) 6.6* 4.2* 28.1 Males with both male and female partners were much more likely than the other 2 male groups to report the use of alcohol and/or drugs with the last sexual encounter. A notably small proportion of males with both sex partners (28%) reported using a condom during the last sexual encounter, compared to 77-79% of other groups (p<0.0001 for condom use, both-sex vs. same-sex males). Males with both sex partners were significantly more likely than the other 2 groups to report being a victim of intimate partner violence in the previous year and a victim of forced sex. * Significant difference compared to group with male & female partners

Results Percent females reporting opposite, same, and both-sex partners, by race & ethnicity Similar to males, non-Hispanic White females (18%) were more likely than non-Hispanic Black (7%) and Hispanic females (8%) to report both male and females partners

Results Female sexual behaviors Sex of partner(s) reported Opposite sex Same sex Both sex N=47,954 N=1,683 N=4,901 % Age at 1st sex <=13 14-15 >=16 24.4* 53.1 22.5* 58.5 35.8 5.8 42.6 51.3 6.2 No. lifetime partners 1 2-5 >=6 41.0* 47.7 11.3* 57.7* 24.7* 17.6 13.6 55.4 31.0 No. ptrs in last 3 months >=2 81.3* 18.7* 47.4 52.6 64.1 35.9 Females with both sex and only same-sex partners were largely similar to each other with regard to risk behaviors. 43% of females with both sex and 59% of females with only same-sex partners reported first sex before age 14 years, compared to 24% of those with opposite-sex partners (p=0.03). Females with male and female partners were more likely than those with opposite-sex partners but equally likely as those with only same-sex partners to report 6 or more lifetime partners and 2 or more partners in the past 3 months. * Significant difference compared to group with male & female partners

Results Female sexual behaviors Sex of partner(s) reported Opposite sex Same sex Both sex Reported: N=47,954 N=1,683 N=4,901 % Alcohol/drugs at last sex 10.8* 14.3 25.9 Condom use 68.8 63.9 55.1 Partner violence (past year) 15.2* 9.3* 34.6 Forced sex (ever) 16.7 2.6* 27.5 Females with male and female partners were also more likely than those with opposite-sex, but equally likely as those with only same-sex partners to report the use of alcohol and/or drugs with the last sexual encounter. There were no differences between groups regarding condom use. Those with male and female partners were more likely than the other female groups to report sexual violence; similar to males with both-sex partners, approximately one-third reported intimate partner violence. Also similar to what was seen for males with both-sex partners, 28% of females with both-sex partners reported forced sex, however the difference in prevalence of forced sex between females with both-sex and opposite sex partners (17%) was not significantly different. * Significant difference compared to group with male & female partners

Results Male sexual identity and behavior Weighted % in each group All males Sex of partner(s) reported Opposite sex Same sex Both sex Heterosexual (Straight) 94 98 57 15 Gay 1 38 Bisexual 3 4 71 Unsure 12 Now I’ll switch gears to talk about sexual identity findings. Along the left side are the identity categories, and across the top are the groups of males according to sex of partners. Groups with discordant identity and behavior are circled. Among males, the greatest degree of discordance (57%) occurred among those who reported exclusively same-sex behavior but a heterosexual identity. Of males with partners of both sexes, 15% reported a heterosexual identity. = discordant group with respect to identity & behavior

Results Female sexual identity and behavior Weighted % in each group All females Sex of partner(s) reported Opposite sex Same sex Both sex Heterosexual (Straight) 87 94 79 26 Gay/lesbian 1 7 4 Bisexual 8 3 13 64 Unsure 2 6 Discordance findings were more striking among females. Among females with only same sex partners, a combined 92% reported a sexual identity other than gay/lesbian; 79% reported a heterosexual identity, and an additional 13% reported a bisexual identity. Of females with male and female partners, 26% considered themselves heterosexual. ++++++++++++++++++ Future analyses of these data will explore identity-behavior discordance as a potential predictor of some of the sexual risk behaviors I’ve just presented. = discordant group with respect to identity & behavior

Limitations Homeless youth and youth in alternative schools not surveyed Missing populations that may have ↑ proportion of persons with same-sex partners Self-reported behaviors subject to social desirability bias No definition or referent period for sexual contact “Sexual intercourse” not defined Sample size did not allow for examination of risk behaviors by race and ethnicity There are some limitations to our analysis. The YRBS misses homeless youth and youth in alternative schools. However, it remains one of the strongest methods for tracking health and risk behaviors among the majority of U.S. adolescents. The YRBS relied on self-report of many sensitive and stigmatized behaviors and experiences, but respondents social desirability bias was likely minimized by the self-administered, anonymous survey procedures. (Additionally, high rates of sexual abuse and multiple sex partners reported by a substantial proportion of our sample suggest that respondents were probably honest in their answers). Sexual contact was not defined in terms of vaginal/anal/oral sex and no referent period was defined for the question. As a study of adolescents, it could be assumed that reported behaviors were recent as the time to have accumulated sexual experiences was relatively short. “Sexual intercourse” was not defined, increasing the possibility that oral sex was not included in the perception of sexual activity, and thereby underestimating respondents who could be included in the analysis. Last, although we report on a larger number of in-school adolescents than other published research, our sample size did not allow for testing for possible variation in behaviors by race and ethnicity.

Conclusions & Implications Almost 1 in 5 NYC high school youth report same-sex partners Prevention messages must be appropriate for a broad audience that includes persons with same-sex attraction/behavior Youth with same-sex partners report earlier age at 1st sex, and the subset with both male & female partners report a higher prevalence of risk behaviors Sexual health education should include the need to inquire about partners’ sex of partners In NYC, our estimate of same-sex behavior is higher than what has been reported in other population-based studies of adolescents. Prevention messages must be appropriate for a broad audience that includes youth with same-sex attraction or behavior; sexual health education programs that emphasize unintended pregnancy prevention and abstinence until marriage are not equally relevant for youth with opposite-sex and same-sex partners. Youth with same-sex partners report an earlier sexual debut, and the subset of adolescents who reported both male and female partners exhibit a higher prevalence of several behaviors that influence STI transmission, such as a greater number of sex partners, use of alcohol and/or drugs with sex, experience with intimate partner violence and sexual abuse, and a lower prevalence of recent condom use for males. Given these risks, sexual health education should include the need for sexually active youth to inquire about the sex of their partners’ partners.

Conclusions & Implications Many students reported intimate partner violence & sexual abuse health care providers should ask teenagers about whether they have been victimized providers should be familiar with available & appropriate referrals Given the discordance between sexual behavior and sexual identity, it is not appropriate to target groups for prevention based on identity Providers of adolescent health care should take thorough sexual histories that ascertain information on sex of partners and specific sexual acts Many respondents with male and female partners were the victims of sexual violence. (Approximately one-third experienced partner violence, and over one-quarter reported sexual abuse). Appropriate intervention to reduce the likelihood of further victimization and psychological and substance abuse problems in adulthood is more likely if pediatricians and school health providers ask about sexual violence when speaking with teenagers. And importantly, providers should know what to do when they find out about sexual violence in terms of available and appropriate referrals, recognizing that those may be very different from what is appropriate for adults. Finally, given the discordance between sexual behavior and sexual identity, it is not appropriate to target groups for prevention based on identity alone, and providers of adolescent care should take thorough sexual histories that ascertain information on sex of partners as well as specific sexual acts.

Acknowledgements NYC DOHMH Division of Epidemiology The NYC schools and students who provide valuable information by completing the YRBS