Identifying Factors Associated with Low-Adherence and Subsequent HIV Seroconversions Among South African Women Enrolled in a Biomedical Intervention Trial

Review of Impact of Risk Reduction Sessions on Sexual Behaviors in HIV Prevention Trials: Insights from Africa

Over the past two decades, numerous HIV prevention trials have targeted thousands of young African women, aiming not only to reduce transmissions through biomedical interventions but also to promote safe sexual practices through intensive risk reduction sessions. The primary objective of this study was to review the impact of risk reduction sessions in HIV prevention trials conducted in Africa. We assessed changes in sexual behaviors among women enrolled in various biomedical intervention trials across the African region using both visual and quantitative evaluations. Meta-analysis techniques were used to estimate overall odds ratios. In a sub-group analysis, we also used semiparametric regression models to capture important features of the associations between sexual behaviors across the study visits with minimal statistical assumptions. Key time points were identified using the "zero-crossing" technique. Overall summary odds ratio (OR) for condom use in last sex was estimated as 2.21 (95% CI 2.06, 2.36). In our sub-group analysis, women who reported multiple sexual partners declined (adjusted odds ratios (aORs) range: 0.61-0.67) while condom use in last sex improved over time (aORs ranged from 2.22-to-2.60); 347(57%) women HIV seroconverted within the first 6-months which was the most crucial time point with substantial reductions in risky behaviors. This review highlights that the gradual cumulative effect of risk reduction sessions, rather than an immediate substantial impact, may have significant implications in clinical research settings. Effective and sustainable risk reduction programs should include biological components such as pre-exposure prophylaxis (PrEP) to reduce HIV transmission.

Contraceptives and sexual behaviours in predicting pregnancy rates in HIV prevention trials in South Africa: Past, present and future implications

OBJECTIVE

Despite all efforts, high pregnancy rates are often reported in HIV biomedical intervention trials conducted in African countries. We therefore aimed to develop a pregnancy risk scoring algorithm for targeted recruitment and screening strategies among a cohort of women in South Africa.

METHODS

The study population was ~ 10,000 women who enrolled in one of the six biomedical intervention trials conducted in KwaZulu Natal, South Africa. Cox regression models were used to create a pregnancy risk scoring algorithm which was internally validated using standard statistical measures.

RESULTS

Five factors were identified as significant predictors of pregnancy incidence:<25 years old, not using injectable contraceptives, parity (<3), being single/not cohabiting and having ≥ 2 sexual partners in the past three months. Women with total scores of 21-24, 25-35 and 36+ were classified as being at "moderate", "high", "severe" risk of pregnancy. Sensitivity of the development and validation models were reasonably high (sensitivity 76% and 74% respectively).

CONCLUSION

Our risk scoring algorithm can identify and alert researchers to women who need additional non-routine pregnancy assessment and counselling, with statistically acceptable accuracy and robustness.