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Development of a prognostic tool exploring female adolescent risk for HIV prevention and PrEP in rural South Africa, a generalised epidemic setting
  1. Sarah Gabrielle Ayton1,2,
  2. Martina Pavlicova2,
  3. Hod Tamir3,
  4. Quarraisha Abdool Karim1,4
  1. 1Department of Epidemiology, Columbia University Mailman School of Public Health, New York City, New York, USA
  2. 2Department of Biostatistics, Columbia University Mailman School of Public Health, New York City, New York, USA
  3. 3ICAP, Columbia University Mailman School of Public Health, New York City, New York, USA
  4. 4Centre for the AIDS Programme of Research in South Africa (CAPRISA), Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, KwaZulu-Natal, South Africa
  1. Correspondence to Sarah Gabrielle Ayton, Department of Biostatistics, Columbia University Mailman School of Public Health, 722 W. 168th Street, 6th floor, Rm. 635, NY 10032, USA; sarah.ayton{at}


Objectives Adolescent females in sub-Saharan Africa bear a disproportionate burden of new HIV infections but have been excluded from prognostic research, such as developed risk calculators. This study examines whether validated risk calculators, which calculate HIV risk among sub-Saharan African women, can be modified to assess HIV risk among adolescent girls. The performance of selected risk variables from validated calculators and the literature was evaluated among adolescent females using modern advanced statistical tools.

Methods Risk variables for the updated tool were selected from the CAPRISA 007 (CAP007) trial (2010–2012) questionnaires. An initially HIV-seronegative cohort of rural South African female high school students (n=1049) aged 14–25 years was selected. The number and characteristics of latent factors, or dimensions, underlying selected variables were assessed using exploratory factor analysis (EFA). The updated tool’s effectiveness identifying trends in adolescent risk were assessed with latent class analysis (LCA).

Results EFA identified two key latent factors: sexual behaviour and socioeconomic risk factors. Latent sexual behaviour risk influenced contraception use (0.883), perceived HIV risk (0.691) and pregnancy (−0.384). Latent socioeconomic risk influenced low HIV knowledge (0.371), financial dependence (0.532), prior HIV testing (−0.379) and alcohol use (−0.332). Using LCA, three underlying categories of adolescent females were identified: those with no, low and high risk of HIV (1.10%, 2.26% and 2.91% 1-year seroconversion rates, respectively). Herpes simplex virus serotype-2, condom contraception, alcohol use, pregnancy and age were significantly associated with higher risk class membership, while non-condom contraception was associated with lower risk class membership.

Conclusions Adolescent females are at unequal risk of acquiring HIV. Findings suggest the updated tool captures two main facets of adolescent characteristics and may identify differential risk. This work supports further investigation to inform development of targeted differentiated interventions and efficient prognostic tools for adolescents in high-risk settings.

  • hiv women
  • africa
  • adolescent
  • epidemiology (general)
  • prognostic indicators

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  • Handling editor Sevgi O Aral

  • Contributors SGA, QAK, MP and HT contributed to the conception and design of the study. SGA and MP contributed to the analysis of data. SGA drafted the manuscript with the help of MP. All authors contributed to the interpretation of the study, revised the manuscript, and critically revised and approved the final manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval University of KwaZulu-Natal Biomedical Ethics Committee (BF105/010 and BE523/14).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available on reasonable request.