Characteristics of women who use hormonal contraceptives and their population-level impacts on HIV infection in a cohort of South African women (2002–2016)

Abstract

Purpose

Women’s choice of contraceptive can have broader implications and may play a significant role in shaping their sexual practices. We aim to identify the characteristics of women who use hormonal injectables and those at high-risk of HIV infection. We also quantify the population-level impact of their shared characteristics on HIV incidence rates.

Materials and methods

Data from 9948 women who enrolled in six-HIV prevention trials conducted in South Africa (2002–2016) were included. We used logistic and Cox regression models and estimated the population-level impact of the use of injectables on HIV incidence in the multifactorial-model setting.

Results

Using hormonal injectables were associated with increased risk of HIV infection (adjusted Hazard ratio (aHR):1.51, 95% CI:1.22, 1.86). At the population level less than 20% of the infections were associated with injectable contraceptives among younger women (i.e., less than 35 years of age). Factors including being single/not-cohabiting, using condoms at last sex, partner-related factors, and STI diagnosis were all identified as shared characteristics of women who preferred using hormonal injectables and those at high-risk of HIV infection. At the population level, these factors were associated with more than 50% of the infections among women younger than 35 years of age.

Conclusions

Our analysis presented evidence for the overlapping characteristics of the women who used hormonal injectables and those at high-risk of HIV infection. These findings reinforce the importance of comprehensive contraceptive counselling to women about the importance of dual protection, such as male condoms and hormonal contraceptives use.

摘要

目的：妇女对避孕方法的选择可能产生广泛的影响, 并可能在性行为方面发挥重要作用。我们的目的是确定应用激素注射剂和处于HIV感染高风险女性的特征。我们还量化了他们的共同特征对艾滋病发病率的群体影响。

材料和方法：数据来自于南非进行的6项HIV预防试验（2002-2016年）中纳入的9948名女性, 我们采用了Logistic和Cox回归模型, 并在多因素模型中评估应用注射剂对艾滋病毒发病率的群体影响。

结果：应用激素注射剂与HIV感染风险增加相关（调整风险比（aHR）：1.51, 95% CI:1.22,1.86）。在群体水平上, 与年轻女性（35岁以下）注射避孕药相关的感染小于20%。包括单身/不同居、最后一次性交时使用避孕套、伴侣相关因素、STI诊断等因素, 都被认为是喜欢应用激素注射女性和HIV病毒感染高危女性的共同特征。在群体水平上, 这些因素中有50%以上与35岁以下的年轻女性感染相关。

结论：我们的分析为应用激素注射剂的女性和那些HIV感染的高危人群的重叠特征提供了证据。这些发现增加了向女性提供全面的避孕咨询的重要性, 使她们了解双重保护的重要性, 如男性避孕套和激素避孕药的应用。

Keywords:

• HIV
• South African women
• contraceptives
• hormonal injectables

Acknowledgements

We thank the study participants and all the South African Medical Research Council HIV Prevention Unit personals who worked in these trials. We acknowledge that main studies associated with these trials have received funding and support from the various sources including: the UK Department for International Development and the Medical Research Council and the Bill & Melinda Gates Foundation.

Disclaimer

The findings and interpretation of this study are those of the authors only.

Ethical standards

Ethical approvals were received from the Research Ethics Committee of the Human Sciences Research Council, South Africa (REC: 5/17/11/10); the Associate Director of Science of the National Centre for HIV and AIDS, Viral Hepatitis, STD and TB Prevention at the USA's (CDC) in Atlanta, Georgia, USA. The study protocol has received by the Human Sciences Research Council (HSRC) Research Ethics Committee (REC: 5/17/11/10) and by the Centres for Disease Control and Prevention. In addition, the principle investigators of the study has received additional approval from the SABSSM data curation team on June 5, 2018. For the clinic-based data: Ethical approval for the trials, including all study protocols and informed consent forms, were received from the University of KwaZulu-Natal Biomedical Research Ethics Committee and the South African Medical Research Council Ethics Committee as; the University of Cape Town Research Ethics Committee; and the South African Medicines Control Council well as the various study-specific Institutional Review Boards.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Informed consent

Study participants who enrolled in these trials provided either written or verbal consent. Participants confirmed their consent by signature or witnessed thumbprint.

Authors’ contributions

HW and TR participated in the design of the study and performed the statistical analysis. NM and TR extracted and merged the data. HW drafted the manuscript. HW, TR and NM interpreted the results. All authors read and approved the final manuscript.

Data sharing statement

Data can be available for researchers who provide a methodologically sound proposal, which will be reviewed by the Trial Management Committees. Proposals should be directed to [email protected]. Any proposal will require approval by Trial Management Committees.

Additional information

Funding

The current study used the site-specific secondary (subgroup) data and did not receive any funding. The authors did not receive any funding for the current study.