Adolescent HIV Risk Profiles: What Can We Learn From Within- and Between-Person Patterns Over Time?

Background and Purpose.  Adolescents worldwide are disproportionately impacted by HIV and other STI, yet prevention efforts face substantial challenges when assessing youths' dynamic risk-taking trajectories. Particularly in resource-limited clinics serving high-risk youth, behavioral data are typically collected cross-sectionally as fixed, categorical variables, hindering examination of risk-taking patterns over time. Interventions addressing youths’ recent circumstances without considering long-term variability may be ineffective.  Conversely, longitudinal studies risk higher attrition rates and delay dissemination of findings to service providers. Using an innovative Sexual Health History Calendar (SHHC), this study investigated adolescents' monthly sexual risk to determine the range of individual risk-taking, variability of risk between- and within-individuals, and patterns of risk-taking over time.

Methods.  A convenience sample of adolescents (n=232; 77% female; 78% Youth of Color) ages 14-22 (Mean=18.6, SD=1.8) was drawn from an urban, Midwestern public teen health clinic.  Participants completed the SHHC, which used contextual life events to enhance recall of risky behaviors (sex partners, protected/unprotected sex, STI, substance use) during the previous 12 months.  Respondents were assigned a sexual risk score for each month (0=abstinent to 5=no condoms+multiple partners). Scores were compared on participant demographics using chi-square, t-tests and ANOVA as appropriate, and by month using multiple regression. Repeated-measures ANOVA was used to partition total sex risk variance into 3 components: between participant, within participant (month), and participant by month interaction.  Examining the total sex risk range for each participant, we identified risk profiles using the growth curve from their 12 sexual risk scores, or their average score when that slope lacked significance. 

Results.  Average sex-risk scores increased significantly over time from 1.38 to 1.84 (β=0.05, t (2734)=6.47, p < .01).  Sex-risk scores did not significantly differ by age, sex, or race/ethnicity; however, youth with same-sex partners reported significantly wider ranges of risk-taking than those with only opposite-sex partners (t (224)=1.974, p=.05). Youths' trajectories yielded five patterns representing distinct profiles: increasing risk over time (positive slope; 34%), decreasing risk (negative slope; 12%), with 54% relatively flat, or variable, but without discernible direction (19% consistently low-risk, 18% moderate, 16% high).  Variance between and within participants (month) were almost equal (0.94 and 0.92, respectively) indicating that in terms of risk-taking over time, youth were as different from themselves as from each other.  Only 30% of participants were sexually constant over time. Youth averaged 2.4 different risk levels over the year; 5% experienced all six risk levels.

Conclusions and Implications.  These findings challenge characterizations of adolescents as simply “high” or “low” risk by illustrating how sexual risk-taking varies significantly, both between and within youth, over time (i.e., even youth with consistently high-risk behavior reported some months with lower risks). Research examining behaviors most recently or “most of the time” may overlook critical information, and, while important, risk “profiles” comparing youth to each other only reveal half of each youth's story.  Future research is needed to develop and test innovative instruments like the SHHC with specific adolescent sub-groups in U.S. and global settings in order to assess youths’ dynamic sexual risk trajectories in context.