Dataset Information

Injectable and oral contraceptives and risk of HIV acquisition in women: an analysis of data from the MDP301 trial.

ABSTRACT:

Study question

Do injectable and oral contraceptives increase the risk of human immunodeficiency virus (HIV) acquisition in women?

Summary answer

After adjusting for confounders, evidence of a significantly increased risk of HIV remained for women using injectable depo-medroxyprogesterone (DMPA) (hazard ratio = 1.49, 95% confidence interval (1.06-2.08)) but not for injectable norethisterone-enanthate (Net-En) or oral contraceptive pills (OC).

What is known already

An association between the use of some types of hormonal contraception (HC) methods and an increased risk of HIV, possibly through changes in the genital tract environment and alterations in the immune response, has been previously observed, although not consistently. A recent systematic review of these studies has highlighted the need for more definitive evidence.

Study design, size, duration

A secondary data analysis of the MDP301 phase 3 microbicide trial was conducted to estimate the effects of use of different methods of HC on the risk of HIV acquisition in women. HIV-negative women (n = 8663) with a median age of 28 years were included in the analysis; 382 HIV seroconverted by 52 weeks follow-up; 10% of women-years were lost to follow-up before 52 weeks.

Participants/materials, setting, methods

Contraceptive use was reported at each 4-weekly visit. Cox proportional hazards (PH) models were used to estimate the effects of baseline and current use of injectable DMPA, injectable Net-En and OC compared with no HC, on the risk of HIV, adjusting for baseline and time-updated covariates. Causal effects for 52 weeks of HC use compared with no HC were estimated in a weighted Cox model, censoring women at deviation from baseline HC use (or non-use) or pregnancy.

Main results and the role of chance

At baseline, 2499 (29%) women were on DMPA, 1180 (14%) on Net-En, and 1410 (16%) on OC; 3574 (40%) not on HC, started HC in follow-up. Adjusted hazard ratios (HR) for baseline HC use, compared with no HC, were 1.38 (95% confidence interval (CI) 1.07-1.78) for DMPA; 1.18 (0.86-1.62) for Net-En and 0.97 (0.68-1.38) for OC. The estimated causal effects of DMPA and Net-En over 52 weeks were: HR = 1.49 (95% CI 1.06-2.08) and HR = 1.31 (95% CI 0.62-1.61), respectively.

Limitations, reasons for caution

A main limitation of the study was that it was a secondary analysis of data from a study that was not designed to investigate this question. Despite our best efforts, we cannot exclude residual confounding to explain the effect of DMPA.

Wider implications of the findings

The results of this study should be reviewed by the World Health Organization to determine whether current recommendations on the use of DMPA in settings with high HIV prevalence require modification.

Study funding/competing interests

MDP is a partnership of African and European academic/government institutions with commercial organizations, which is funded by the UK Government (DFID and MRC), with support from IPM and EDCTP. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: None.

SUBMITTER: Crook AM

PROVIDER: S-EPMC4093991 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:To assess the effect of oral and injectable contraceptive use compared to nonhormonal contraceptive use on HIV acquisition among Southern African women enrolled in a microbicide trial.This is a prospective cohort study using data from women enrolled in HIV Prevention Trials Network protocol 035. At each quarterly visit, participants were interviewed about self-reported contraceptive use and sexual behaviors and underwent HIV testing. Cox proportional hazards regression was used to assess the effect of injectable and oral hormonal contraceptive use on HIV acquisition.The analysis included 2830 participants, of whom 106 became HIV infected (4.07 per 100 person-years). At baseline, 1546 (51%) participants reported using injectable contraceptives and 595 (21%) reported using oral contraceptives. HIV incidence among injectable, oral and nonhormonal contraceptive method users was 4.72, 2.68 and 3.83 per 100 person-years, respectively. Injectable contraceptive use was associated with a nonstatistically significant increased risk of HIV acquisition [adjusted hazard ratio (aHR)=1.17; 95% confidence interval (CI) 0.70, 1.96], while oral contraceptive use was associated with a nonstatistically significant decreased risk of HIV acquisition (aHR=0.76; 95% CI 0.37,1.55).In this secondary analysis of randomized trial data, a marginal, but nonstatistically significant, increase in HIV risk among women using injectable hormonal contraceptives was observed. No increased HIV risk was observed among women using oral contraceptives. Our findings support the World Health Organization's recommendation that women at high risk for acquiring HIV, including those using progestogen-only injectable contraception, should be strongly advised to always use condoms and other HIV prevention measures.Among Southern African women participating in an HIV prevention trial, women using injectable hormonal contraceptives had a modest increased risk of HIV acquisition; however, this association was not statistically significant. Continued research on the relationship between widely used hormonal contraceptive methods and HIV acquisition is essential.

Project description:BackgroundSeveral observational studies have reported that HIV-1 acquisition seems to be higher in women who use depot medroxyprogesterone acetate (DMPA) than in those who do not use hormonal contraception. We aimed to assess whether two injectable progestin-only contraceptives, DMPA and norethisterone enanthate (NET-EN), confer different risks of HIV-1 acquisition.MethodsWe included data from South African women who used injectable contraception while participating in theVOICE study, a multisite, randomised, placebo-controlled trial that investigated the safety and efficacy of three formulations of tenofovir for prevention of HIV-1 infection in women between Sept 9, 2009, and Aug 13, 2012. Women were assessed monthly for contraceptive use and incident infection. We estimated the difference in incident HIV-1infection between DMPA and NET-EN users by Cox proportional hazards regression analyses in this prospective cohort. The VOICE trial is registered with ClinicalTrials.gov, NCT00705679.Findings3141 South African women using injectable contraception were included in the present analysis: 1788 (56·9%)solely used DMPA, 1097 (34·9%) solely used NET-EN, and 256 (8·2%) used both injectable types at different times during follow-up. During 2733·7 person-years of follow-up, 207 incident HIV-1 infections occurred (incidence7·57 per 100 person-years, 95% CI 6·61–8·68). Risk of HIV-1 acquisition was higher among DMPA users (incidence 8·62 per 100 person-years, 95% CI 7·35–10·11) than among NET-EN users (5·67 per 100 person-years, 4·35–7·38;hazard ratio 1·53, 95% CI 1·12–2·08; p=0·007). This association persisted when adjusted for potential confoundingvariables (adjusted hazard ratio [aHR] 1·41, 95% CI 1·06–1·89; p=0·02). Among women seropositive for herpes simplex virus type 2 (HSV-2) at enrolment, the aHR was 2·02 (95% CI 1·26–3·24) compared with 1·09 (0·78–1·52)for HSV-2-seronegative women (pinteraction=0·07).InterpretationAlthough moderate associations in observational analyses should be interpreted with caution, thesefi ndings suggest that NET-EN might be an alternative injectable drug with a lower HIV risk than DMPA in high HIV-1 incidence settings where NET-EN is available.FundingNational Institutes of Health, Mary Meyer Scholars Fund, and the Ruth Freeman Memorial Fund.

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