Characterizing a sexual health and HIV risk stratification scale for sexually active adolescent girls and young women (AGYW) in Tanzania

Adolescent girls and young women (AGYW) aged 15 to 24 years face disproportionately high risks of acquiring HIV and other sexually transmitted infections (STIs). A sexual health risk stratification tool can support the development and implementation of tailored HIV and STI prevention services for sub-groups of at-risk AGYW. Data were collected among sexually active AGYW aged 15 to 24 years in Tanzania between April 2015 and March 2017. Exploratory and confirmatory factor analyses were conducted to construct and assess the latent structure of a ten-item scale for rapid assessment of sexual health risks. Items with high factor loadings and minimal cross loadings were retained in the final scale. Scale performance was appraised against condomless sex (defined as unprotected vaginal or anal intercourse) reported by AGYW for construct validity. A three-factor structure of vulnerability to HIV among AGYW was supported with subscales for socioeconomic vulnerability; lack of adult support; and sexual behavioral risks. The chi-square goodness-of-fit test, root mean square error of approximation, comparative fit index, and Tucker-Lewis index indicated a strong goodness-of-fit of the three-factor scale. Cronbach alphas (0.55 for socioeconomic vulnerability, 0.55 for lack of support, and 0.48 for sexual risk) indicated sub-optimal internal consistency for all sub-scales. The factor-item and factor-factor correlations identified in these analyses were consistent with the conceptual framework of vulnerability of HIV infection in AGYW, suggesting good construct validity. The scale also demonstrated a statistically significant association with condomless sex and could be potentially used for sexual health risk stratification (OR = 1.17, 95% CI: 1.12, 1.23). The sexual health and HIV risk stratification scale demonstrated potential in identifying sexually active AGYW at high risk for HIV and other STIs. Ultimately, all AGYW in Tanzania are not at equal risk for HIV and this scale may support directing resources towards those at highest risk of HIV.