Predictors Of Sexual Risk Behavior Research Articles

Sexual Health Knowledge and Sexual Self-Efficacy as Predictors of Sexual Risk Behaviors in Women

According to the Center for Disease Control (CDC), the proportion of acquired immunodeficiency syndrome (AIDS) diagnoses among women in the United States has more than doubled between 1984 and 2019 and rates of sexually transmitted diseases (STDs) in all individuals increased 30% between 2015 and 2019. Further, the CDC has designated women ages 13 to 44 years as a group vulnerable to human immunodeficiency virus (HIV) and STD infection, in part due to frequency of engaging in sexual risk behaviors. Sexual self-efficacy is associated with decreased sexual risk behaviors and counters norms that emphasize passivity and compliance as traditional sexual behavior in women. In the current study, we assessed knowledge of HIV and STD transmission and risk factors, sexual self-efficacy, and frequency of sexual risk behaviors in 281 woman-identified respondents aged 18–44 years in an online survey. Knowledge of HIV and STDs was low (averages of 63.3% and 49.9%, respectively). Younger women, and women who identified as single, White, and/or LGBTQ+ reported more sexual risk behaviors. HIV knowledge and sexual self-efficacy were independently associated with fewer risk behaviors and significantly interacted to predict sexual risk behaviors. STD knowledge and sexual self-efficacy were independently associated with fewer sexual risk behaviors. These findings highlight the need for comprehensive, widespread, and identity-inclusive sexual health education.

Adolescent sexual risk behaviors and participation in structured leisure activities (SLA): Role of socio-demographic characteristics and school-related behaviors

Adolescence is the transitional period between childhood and adulthood during which many physical, cognitive, social and emotional changes take place, characterized by an increasing interest in romantic and sexual relationships. During adolescence, young people enter into their first sexual partnerships. This may involve behaviors referred to as sexual risk behaviors. The aim of this study was to gain insight into the prevalence of sexual risk behaviors and to determine whether socio-demographic characteristics and school-related behaviors contribute to sexual risk behaviors among adolescents, independent of participation in SLA. The study was conducted from April to June 2021 in Croatia. The sample consisted only of students who reported having had sexual intercourse (N=702; 28.6%). Participants were between 14 and 21 years (46.3% female). Logistic analyses were conducted. The results of this study showed that socio-demographic characteristics make only a limited contribution to the sexual risk behaviors studied. However, it is evident that school-related behaviors are associated with sexual risk behaviors among adolescents, with slight differences depending on their participation in SLA. That is, better grades are a protective factor for sexual risk behavior for both those who do not participate in SLA and those who do, while intentionally skipping school is a risk factor for sexual risk behavior only for those who do participate in SLA. Even though the results show that some school-related behaviors are predictors of sexual risk behavior, it is not enough to implement preventive interventions only in school or leisure settings. It is important to intervene in all areas that influence adolescent development, because a comprehensive preventive approach that addresses all areas can have a greater impact on adolescent development. Therefore, it is necessary to plan comprehensive, evidence-based interventions targeting individuals and their environments, including SLA, to prevent sexual risk behaviors among adolescents.

Characteristics and Sexual Risk Behavior of Men Who Never Tested for HIV in Zambia.

Compared with women and girls, proportionately fewer men and boys in sub-Saharan Africa receive HIV testing, treatment, and other services. This study determined factors associated with never testing for HIV and examined never testing as a predictor of sexual risk behavior among men in Zambia. The sample included 2,609 men aged 15 to 24 from the 2018 Zambia Demographic and Health Survey. Logistic regression results revealed that compared with men who ever tested for HIV, men who never tested were more likely to be younger, have less education, have no children, be unemployed, and belong to the low wealth bracket. They also had a higher likelihood of not using a condom at last sex but were less likely to have more than five lifetime sexual partners. HIV prevention programs can use sociodemographic characteristics to identify those who have a lower likelihood of testing for HIV. Prevention programs can use sociodemographic characteristics to develop profiles of those who may especially need to be targeted by initiatives to promote HIV testing. Awareness does not always engender behavior change; therefore, in addition to knowledge of HIV status, risk reduction should also be emphasized.

Sexual Risk Behavior in HIV-Uninfected Pregnant Women in Western Uganda

Our aim was to identify sexual risk behavior among HIV-negative pregnant women in Kabarole District, Uganda, by conducting a cross-sectional study among 1610 women within three healthcare settings. One in six women engaged in HIV-specific risk behaviors including multiple sexual partners or alcohol abuse; 80% of the pregnant women reported to generally abstain from using condoms. In multivariate analysis, predictors of sexual risk behavior included being a client of the public health facilities as compared to the private facility (AOR 3.6 and 4.8, p < 0.001), being single, widowed or divorced or not cohabiting with the partner (AOR 4.7 and 2.3, p < 0.001), as well as higher household wealth (AOR 1.8, p < 0.001) and lack of partner status knowledge (AOR 1.6, p = 0.008). Self-estimated risk perception was linked with engagement in HIV-related risk behaviors except for alcohol abuse. Our findings indicate that reducing risky behaviors in pregnancy in order to prevent HIV should be a high-priority public health concern.

Sexual Risk Behavior among Adolescents Seeking Treatment for Posttraumatic Stress Disorder: Exploring Psychosocial & Symptom Correlates.

Adolescents exposed to trauma experience disproportionate rates of HIV/STI. However, integrated treatment for trauma and sexual risk behavior is rare. To inform integrated prevention efforts, the current study describes prevalence and correlates of sexual risk behavior among adolescents seeking treatment for symptoms of posttraumatic stress and substance use disorders. Adolescents aged 13-18years (N = 135; 88% female) with histories of interpersonal violence exposure completed pre-treatment questionnaires in a randomized controlled trial of an integrated psychotherapy for trauma and substance use symptomology. Adolescents reported high rates of sexual risk behaviors relative to national estimates and general mental health treatment samples. Symptoms of reexperiencing, substance use, and peer deviance were related to sexual risk behavior beyond the influence of other trauma symptoms. Individual and contextual psychosocial factors may be stronger predictors of sexual risk behavior than posttraumatic stress disorder symptoms among adolescents with trauma symptomology. Integrated interventions targeting traumatic stress, substance use, and sexual risk behavior concurrently may prevent revictimization and HIV/STI incidence among trauma-exposed youth.

Minority Stressors and Identity Affirmation as Predictors of Condomless Sex Among Self-Identified Bisexual Men: The Role of Partner Gender.

Bisexual men are at increased risk for HIV/STI and early pregnancy involvement compared to heterosexual men, and minority stressors (e.g., enacted and internalized stigma) are associated with sexual risk behavior in samples of gay and bisexual men. However, few studies have specifically focused on bisexual men, and little is known about the unique predictors of sexual risk behavior in this population. Further, few studies have focused on positive sexual orientation-related factors such as identity affirmation, which may be protective against sexual risk behavior. As such, the goals of the current study were to examine minority stressors and identity affirmation as predictors of condomless sex among self-identified bisexual men, and whether these associations differed as a function of partner gender. We used four waves of data spanning 24months from a subset of self-identified bisexual men in a larger cohort of gay and bisexual men ages 16-29 years at enrollment. At each wave, participants reported on up to four partners, allowing us to examine within-person associations. We used mixed effects negative binomial models to examine the associations between our predictors (discrimination, internalized binegativity, and identity affirmation) and condomless sex acts. In addition, we tested whether partner gender moderated each of the associations by including interaction effects in each of the models. Results indicated that higher levels of internalized binegativity and lower levels of identity affirmation were associated with less condomless sex with female partners, but they were not associated with condomless sex with male partners. Discrimination was not associated with condomless sex with male or female partners. These findings suggest that predictors of condom use among self-identified bisexual men differ as a function of partner gender, and they highlight the need to identify strategies to promote sexual health while also supporting positive identity development in this population.

Predictors of HIV sex risk behavior among women in US drug treatment programs: NIDA CTN trial results

HIV prevention for women with substance use disorders is a public health priority. To identify characteristics associated with sexual risk among women in outpatient substance abuse treatment we categorized 809 screened women into three groups: (1) sexually inactive, (2) sexually active with consistent condom use, and (3) sexually active with inconsistent condom use. Multinomial logistic regression analyses were used to examine demographics, substance use and treatment characteristics, and regional HIV seroprevalence as predictors of sexual risk behavior. Younger age and attending psychosocial (PS) treatment were significantly associated with being at higher HIV risk. HIV prevention should be tailored to address HIV risk in younger women in PS treatment.

Depressive symptoms as a longitudinal predictor of sexual risk behaviors among African-American adolescents.

Understanding individual level factors associated with sexual risk behaviors among African-American adolescents remains an important public health priority. The current secondary data analysis examined the longitudinal association between a baseline assessment of depressive symptoms and sexual risk behaviors reported 6 months later; the purpose was to determine whether the association of depressive symptoms to risky sex varies as a function of gender. A secondary aim was to examine self-efficacy for sex refusal and condom use assessed at a 3-month follow-up as mediators of the depressive symptoms-sexual risk relationship. The sample consisted of 782 sexually active African-American adolescents (Mage = 15.3 years, SD = 1.08; 54% female) recruited to participate in a sexual health intervention trial. Data analyses focused on vaginal sex, and outcomes included: (a) sexual activity with 2 or more partners in the previous 3 months; (b) the relative frequency of condom use in the previous 3 months; (c) noncondom use at last occasion of sex; and (d) positive sexually transmitted infection (STI) screening. Depressive symptoms predicted sex with 2 more partners for female participants, but no other risk markers for the sample as a whole. However, there was a significant indirect effect of depressive symptoms on condomless sex via decreased condom use self-efficacy for both male and female adolescents. These findings have important implications for HIV/STI prevention, in which behavioral interventions may benefit from modules that include a focus on the influence of mood on self-efficacy for safer sex practices. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Factors Associated With Sexual Risk Behaviors Among People Who Use Drugs in Communities in Cambodia.

In Cambodia, HIV prevalence at 4% remains high among people who use drugs (PWUD). Complex and overlapping risk behaviors may enhance sexual transmission risk beyond PWUD. This study, therefore, aims to assess the factors associated with sexual risk behaviors among PWUD. Respondent Driven Sampling was used to recruit 1626 PWUD. Univariate and multivariate logistic regression analyses were used to identify factors associated with transmission risk including that high mental disorder scores were a strong predictor of sexual risk behaviors (odds ratio [OR] ranged from 1.9 to 2.8). Factors associated with sexual risk behaviors varied by gender: for men, these included geographical regions, non-married status, and heroin use; and for women, factors were age ≤20 years (OR = 5.4), living with friends (OR = 6.4), living in Central coastal region (OR = 6.1), and heroin use (OR = 4.8).

Sexual behaviors, risks, and sexual health outcomes for adolescent females following bariatric surgery

BackgroundAdolescents females with severe obesity are less likely to be sexually active, but those who are sexually active engage in risky sexual behaviors. ObjectivesTo examine patterns and predictors of sexual risk behaviors, contraception practices, and sexual health outcomes in female adolescents with severe obesity who did or did not undergo bariatric surgery across 4 years. SettingFive academic medical centers. MethodsUsing a prospective observational controlled design, female adolescents undergoing bariatric surgery (n = 111; Mage = 16.95 ± 1.44 yr; body mass index: MBMI = 50.99 ± 8.42; 63.1% white) and nonsurgical comparators (n = 68; Mage = 16.18 ± 1.36 yr; MBMI = 46.47 ± 5.83; 55.9% white) completed the Sexual Activities and Attitudes Questionnaire at presurgery/baseline and 24- and 48-month follow-up, with 83 surgical females (MBMI = 39.27 ± 10.08) and 49 nonsurgical females (MBMI = 48.56 ± 9.84) participating at 48 months. ResultsMost experienced sexual debut during the 4-year study period, with a greater increase in behaviors conferring risk for sexually transmitted infections (STIs) for surgical females (P = .03). Half (50% surgical, 44.2% nonsurgical, P = .48) reported partner condom use at last sexual intercourse. The proportion of participants who had ever contracted an STI was similar (18.7% surgical, 14.3% nonsurgical). Surgical patients were more likely to report a pregnancy (25.3% surgical, 8.2% nonsurgical, P = .02) and live birth (16 births in 15 surgical, 1 nonsurgical), with 50% of offspring in the surgical cohort born to teen mothers (age ≤19 yr). ConclusionsBariatric care guidelines and practices for adolescent females must emphasize the risks and consequences of teen or unintended pregnancies, sexual decision-making, dual protection, and STI prevention strategies to optimize health and well-being for the long term.

Perceived HIV risk as a predictor of sexual risk behaviors and discrimination among high-risk women

ABSTRACTHIV risk perception and discrimination are important determinants of HIV prevention among vulnerable populations. Using Detroit’s 2016 National HIV Behavioral Surveillance (NHBS) Survey, we evaluated demographic variables, risk behaviors, and perception of HIV stigma and discrimination stratified by perceived HIV risk (high, medium, low) in a sample of high-risk women. Significant variables were identified using Pearson Chi-squared tests and one-way analysis of variance tests. Among 541 females surveyed, 93.0% were black and 87.7% lived in poverty. Women’s poverty (p = .010), employment (p = .012), insurance (p = .024) and homelessness status (p < .001) were all significantly associated with their level of HIV risk perception. Among women with low HIV risk perception (76.7%), the majority did not know their partner’s HIV status at last intercourse (68.7%, p = .007), had unprotected anal/vaginal sex in the past year (86.7%, p = .025), participated in sex exchange (63.4%, p < .001), and did not use condoms with a partner with HIV-unknown status (87.2%, p < .001). Half of the women agreed or strongly agreed most people would not be friends with someone with HIV (50.4%), and 46.3% agreed or strongly agreed most people would support PLWH to live or work where they want. Compared to women with low HIV risk perception, women with high perceived HIV risk were more likely to agree or strongly agree most people would discriminate against someone with HIV (87.3% vs. 76.8%) and that people who got HIV via sex exchange or drugs got what they deserve (46.6% vs. 25.8%). Women’s perceived HIV risk was not significantly associated with these discriminatory attitudes. Despite multiple risk behaviors significantly associated with the level of perceived HIV risk in the sample, the NHBS survey demonstrates many women with high-risk behaviors still perceive themselves to be at low risk. Our findings highlight a complex interaction of risk perception, risk behaviors and stigma surrounding HIV in high-risk women.

Is Sexual Abuse a Unique Predictor of Sexual Risk Behaviors, Pregnancy, and Motherhood in Adolescence?

This study tested sexual abuse as a unique predictor of subsequent adolescent sexual behaviors, pregnancy, and motherhood when in company with other types of maltreatment (physical abuse, neglect) and alternative behavioral, family, and contextual risk factors in a prospective, longitudinal study of maltreated (n=275) and comparison (n=239) nulliparous females aged 14-19years old assessed annually through 19years old. Hierarchical regression was used to disentangle risk factors that account for the associations of maltreatment type on risky sexual behaviors at 19years old, adolescent pregnancy, and adolescent motherhood. Findings indicate that sexual and physical abuse remain significant predictors of risky sexual behaviors, and that sexual abuse remains a significant predictor of adolescent motherhood when alternative explanatory variables are controlled.

Sex-related marijuana expectancies as predictors of sexual risk behavior following smoked marijuana challenge.

Marijuana use has been associated with sexual risk behavior, but the mechanisms that underlie this relationship are not well understood. The present study examined whether marijuana acutely increased sexual risk on a behavioral decision-making task and whether sex-related marijuana outcome expectancies influenced sexual risk decisions after marijuana administration. Participants were heterosexual marijuana users (n = 126) who were randomly assigned to 1 of 4 study conditions using a 2 × 2 factorial design crossing drug administration (received 2.8% delta-9-tetrahydrocannabinol [THC] or 0% THC) with instructional set (told THC or told placebo). Participants completed a self-report measure of sex-related marijuana outcome expectancies at baseline and estimated likelihood of using condoms with a new and a steady partner in an interactive sexual role-play task (SRT) after smoking. In gender-specific analyses, there was a significant interaction of drug administration by sex-related outcome expectancies, such that for men in the received-placebo conditions, more salient sex-related marijuana outcome expectancies were associated with increased likelihood for sex without a condom with a new partner. Among women, there was no interaction or main effect of drug administration but more salient sex-related marijuana outcome expectancies were associated with increased likelihood of sex without a condom with a steady but not new partner. Findings suggest marijuana does not acutely increase risk for engaging in sexual risk behaviors. By contrast, sex-related marijuana outcome expectancies may play a more significant role in sexual decision-making process among marijuana users. (PsycINFO Database Record

Sexual risk behavior among HIV-positive persons in Jamaica.

HIV/AIDS remains a global public health challenge, especially in sub-Saharan Africa and the Caribbean. Sexual risk behaviors among HIV-positive persons place their partners at risk for HIV transmission and other sexually transmitted infections. Stopping transmission acts among HIV-positive people is crucial in reversing HIV incidence. This study aimed to assess the prevalence and predictors of sexual risk behaviors among HIV-positive individuals in clinical care in Northwestern Jamaica. A cross-sectional survey of 118 (33 males and 85 females) HIV-positive individuals was used to assess demographic and health characteristics, HIV/AIDS knowledge, attitudes, and beliefs and sexual risk behaviors. About 12% of the study population stated that they had unprotected anal or vaginal sex without disclosing their HIV status. Participants who agreed that condoms reduce the risk of HIV transmission were 13.1 times more likely to use condoms during their last sexual encounters(95% CI: 2.1-79.0) than those who disagreed. About 75% of participants reported using a condom every time they had sexual intercourse in the past year, while 25% used condoms irregularly. Participants who had unprotected anal or vaginal sex without disclosing their status were less likely to have used condoms during the last sexual encounter (OR=0.1; 95% CI: 0.02-0.5). The prevalence of unsafe sex remains high among sexually active people living with HIV/AIDS in Jamaica. Study participants who engaged in unprotected sex without disclosing their HIV-positive status potentially place their partners at risk for HIV transmission and other sexually transmitted infections. The study findings highlight the need to promote safe sexual behaviors and a positive social environment for people living with HIV/AIDS in Jamaica.

HIV Risk Perception, HIV Knowledge, and Sexual Risk Behaviors among Transgender Women in South Florida.

Transgender women experience a variety of factors that may contribute to HIV risk. The purpose of this study was to explore links among HIV risk perception, knowledge, and sexual risk behaviors of transgender women. A descriptive, correlational study design was used. Fifty transgender women from the South Florida area were enrolled in the study. Transgender women completed a demographic questionnaire and standardized instruments measuring HIV risk perception, knowledge, and sexual risk behaviors. Transgender women reported low levels of HIV risk perception, and had knowledge deficits regarding HIV risk/transmission. Some participants engaged in high-risk sexual behaviors. Predictors of sexual risk behaviors among transgender women were identified. More research is needed with a larger sample size to continue studying factors that contribute to sexual risk behaviors in the understudied population of transgender women. Evidence-based guidelines are available to assist public health nurses in providing care for transgender women. Nurses must assess HIV perception risk and HIV knowledge and provide relevant education to transgender women on ways to minimize sexual risk.

Types and Characteristics of Childhood Sexual Abuse: How Do They Matter in HIV Sexual Risk Behaviors Among Women in Methadone Treatment in New York City?

Background: Childhood sexual abuse (CSA) is often considered an important distal factor in HIV sexual risk behaviors; however, there are limited and mixed findings regarding this relationship among women experiencing substance use problems. In addition, research with this population of women has yet to examine differences in observed CSA-HIV sexual risk behaviors relationships by CSA type and characteristics. Objectives: This study examines relationships between CSA coding, type, and characteristics and HIV sexual risk behaviors with main intimate partners among a random sample of 390 women in methadone treatment in New York City who completed individual interviews with trained female interviewers. Results: Findings from logistic regression analyses indicate that CSA predicts substance use with sexual activity, with variations by CSA coding, type, and characteristics; however, the role of CSA is more limited than expected. Having a main partner with HIV risk mediates some relationships between CSA and drinking four or more drinks prior to sex. Intimate partner violence is the most consistent predictor of sexual risk behaviors. Other salient factors include polysubstance use, depression, social support, recent incarceration, relationship characteristics, and HIV status. Conclusions/Importance: This study contributes to understanding of relationships between CSA and HIV sexual risk behaviors and key correlates associated with HIV sexual risk behaviors among women in methadone treatment. It also highlights the complexity of measuring CSA and its association with sexual risk behaviors and the importance of comprehensive approaches to HIV prevention that address psychological, relational, situational, and substance use experiences associated with sexual risk behaviors among this population.

Trauma symptoms, internalized stigma, social support, and sexual risk behavior among HIV-positive gay and bisexual MSM who have sought sex partners online

ABSTRACTGay, bisexual, and other men who have sex with men (MSM) remain the highest risk group for HIV infection. One reason is the increased use of the Internet to meet potential sex partners, which is associated with greater sexual risk behavior. To date, few studies have investigated psychosocial predictors of sexual risk behavior among gay and bisexual men seeking sex partners online. The purpose of the current study was to test a conceptual model of the relationships between trauma symptoms indexed on the event of HIV diagnosis, internalized HIV stigma, and social support on sexual risk behavior among gay and bisexual MSM who seek sex partners online. A sample of 142 gay and bisexual MSM recruited on- and offline completed a comprehensive online assessment battery assessing the factors noted above. A number of associations emerged; most notably internalized HIV stigma mediated the relationship between trauma-related symptoms indexed on the event of HIV diagnosis and sexual risk behavior with HIV-negative and unknown serostatus sex partners. This suggests that gay and bisexual MSM who are in greater distress over their HIV diagnosis and who are more sensitive to HIV stigma engage in more HIV transmission risk behavior. As sexual risk environments expand with the increasing use of the Internet to connect with others for sex, it is important to understand the predictors of sexual risk behavior so that tailored interventions can promote sexual health for gay and bisexual MSM seeking sex online.

The impact of childhood gender expression on childhood sexual abuse and psychopathology among young men who have sex with men

Young men who have sex with men (MSM) are a risk group highly vulnerable to HIV infection and psychiatric symptoms are direct predictors of sexual risk behavior in MSM. Childhood sexual abuse (CSA) is associated with psychiatric symptomology in adolescence, and MSM are disproportionately impacted by CSA compared to heterosexuals. Some evidence suggests that childhood gender nonconformity, a natural variation of human gender expression, is more common in MSM than heterosexual males and places MSM at greater risk for CSA. This study examined whether or not childhood gender expression moderated the association between incidents of unwanted, early sexual experiences occurring before age 13 (ESE) and current psychiatric symptomology in a community-based sample of 449 young MSM aged 16–20. Analyses revealed significant bivariate associations between ESE and psychological symptoms, and significant multivariable associations between ESE, gender nonconformity and psychiatric outcomes. Young MSM with childhood gender nonconformity may be disproportionately victimized by CSA thereby increasing their likelihood of developing psychiatric symptoms in adolescence. Early intervention addressing these factors may help reduce lifetime negative sequelae.

Developmental Pathways to Sexual Risk Behavior in High-Risk Adolescent Boys

Adolescent boys' involvement in pregnancy and sexual risk behavior is a public health concern. Although research has identified predictors of sexual risk behavior during adolescence, few studies have investigated precursors to boys' sexual risk behavior beginning in early childhood, the identification of which could serve to inform interventions and help reduce involvement in pregnancy. Our goal was to identify early developmental pathways associated with sexual risk behavior in a sample of low-income adolescent boys. Data from a prospective longitudinal study in 310 at-risk boys were used to examine externalizing problems, mothers' depressive symptoms, and low-nurturant parenting in early childhood (1.5, 2, and 3.5 years old) and daring, externalizing, parental monitoring, and deviant peer affiliation during emerging adolescence (11 and 12 years old) as precursors of sexual risk behavior between the ages 15 and 20 years. Structural equation modeling was used to explore pathways associated with later high-risk sexual behavior (HRSB). In multivariate analyses, adolescent daring and deviant peer affiliation at age 12 were associated with later HRSB. Furthermore, deviant peer affiliation during emerging adolescence mediated the relationship between mothers' depressive symptoms and nurturant parenting during early childhood and later adolescent HRSB. Family-based risk factors in early childhood are predictive of HRSB in adolescence but are also influenced, and in some cases mediated, by relationships with peers and child characteristics during emerging adolescence.

Psychological and socio-demographic variables associated with sexual risk behavior for sexually transmitted infections/HIV

New diagnoses of sexually transmitted infections (STIs) and HIV are rising in the adult population. The main objective of this study was to analyze whether knowledge of STIs/HIV, worry about STIs/HIV and pregnancy, and self-efficacy to refuse sex are predictors of sexual risk behaviors among Spanish young and adults. The study sample was composed of 1,106 young and adults of both sexes aged between 17 and 55 years. Results showed that being single, homosexual, having been tested for HIV, having previously contracted an STI, having a college education and earning a monthly income of €900 or more were the characteristics associated with higher scores in knowledge of STIs/HIV. Self-efficacy to refuse sex predicted most vaginal and anal sexual behaviors (i.e., age at vaginal and anal sex initiation and the number of couples that have remained vaginal sex). We also found that participants with greater knowledge of STIs/HIV reported older age at vaginal sex initiation and higher condom use in the first vaginal sexual contact. We consider that these findings can be useful for the development of STI/HIV prevention programs.