Respondent-driven sampling: A novel approach for estimating abortion incidence in Soweto, South Africa

Accurately estimating abortion incidence comes with many challenges. Reporting of abortions that occur within the formal health care system is often incomplete or inaccurate, and there is a lack of individual-level data on abortions that occur outside the formal health care system. Indirect methods for estimating the incidence of abortions rely on assumptions and extrapolations that are often difficult to test. Respondent-driven sampling (RDS), a methodology that relies on peer-to-peer recruitment, has been used to estimate the prevalence of health outcomes among hidden populations, and may be a potential strategy for abortion incidence estimation.

In South Africa, the Choice on Termination of Pregnancy Act, passed in 1996, allows for legal termination of pregnancy on request up to 12-weeks gestation, under socioeconomic, incest, rape, and medical grounds from 12 to 20 weeks, and to save a person’s life after 20 weeks. While abortion services are provided free of charge in the public sector, barriers to abortion access—such as a shortage of trained and willing providers and a lack of dedicated facilities in which to perform abortions—have resulted in waiting lists that delay abortions by weeks.  Informal sector abortions are widely known to occur, but the prevalence, safety, and efficacy of informal sector abortion, women’s experiences with informal sector abortion, and its impact on women’s health in South Africa is unknown. 

Based on lessons learned from a pilot study in Cape Town and prior formative research, we conducted a RDS study to estimate the cumulative lifetime incidence of abortion (both within and outside the formal health care sector) among women of reproductive age in Soweto, South Africa. With the assistance of community partners, we identified 11 initial participants,all of whom completed a baseline questionnaire and were given three recruitment coupons to distribute to eligible participants in their peer networks. Between April and December 2018, we recruited 849 eligible participants.

Findings from this work are forthcoming. Learn more about our work in South Africa here.