We used baseline survey data from participants enrolled in AYAZAZI (meaning “knowing themselves” in isiZulu), a prospective cohort study which aimed to understand patterns of socio-behavioural and biomedical HIV risk among male and female youth aged 16-24 years. AYAZAZI was conducted at two sites: the MatCH Research Unit (MRU), Commercial City research site in Durban, KwaZulu-Natal (KZN) Province and the Perinatal HIV Research Unit (PHRU) located at Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg, Gauteng Province (GP). Participants were followed-up every six months until 12 (Durban) or 18 (Soweto) months.
The AYAZAZI study inclusion criteria included being 16-24 years of age, residing in Soweto or Durban, self-reporting an HIV-negative or unknown HIV status, and being willing and able to provide voluntary written informed consent for study procedures. Exclusion criteria included current participation in another clinical or observational HIV prevention study.
Participants were recruited using posters, pamphlets, word-of-mouth, and in-person community outreach to recruit 425 participants (253 females, 172 males) across both sites. In Soweto, participants were also recruited through an HIV testing and counselling clinic at the PHRU while in Durban, participants were also recruited through a public reproductive health clinic at Commercial City. The study was undertaken between 2014 and 2017.
Participants completed an on-site structured, online questionnaire (supported by DataFAXTM software) conducted in English, isiZulu, or Sesotho, as per participant preference at enrolment, administered in-person by youth interviewers. The questionnaire assessed demographic characteristics, social determinants of health, health care-seeking behaviours, sexual behaviours in the six months prior to the, pregnancy and contraceptive history, substance use, experiences of violence, and self-perceived HIV risk. This analysis used baseline survey data from female participants who reported ever having had consensual sex.
Exposure of interest: Adolescent pregnancy
A three-level variable was created to compare females who had a pregnancy as an adolescent (aged 15-19), a pregnancy not as an adolescent (aged 20-24), or never being pregnant. Age at pregnancy was determined by subtracting the participant’s date of birth from the reported end date of the first pregnancy.
Outcome of interest: Current contraceptive use
Participants were considered to be effective contraception users if they reported using any of the following methods in the last six months: consistent condom use (defined as condom use at last sex with all reported partners), using oral contraceptive pills, two- or three-monthly hormonal injectable, hormonal implant, or dual method (i.e. consistent condom use and hormonal method). Participants were considered non-users of contraception if they reported not using any method or only using ineffective contraception methods (defined as inconsistent condom use, withdrawal, or only using emergency contraception as their main contraception method) in the last six months.
Socio-demographic variables
The baseline questionnaire assessed site (Durban vs. Soweto), age category (16-19, 20-24), sexual orientation (straight vs. lesbian, bisexual), housing (formal vs. reconstructive development project [RDP], hostel, shack, or living outdoors), income in South African Rand (ZAR) (<400, 401-1600, 1601+), and currently a learner (in high school) or student (post high school) (yes vs no).
Household hunger was assessed using the 9-item Radimer (Radimer, Olson and Campbell 1990)11 household hunger scale. Participants were asked a series of questions about their experiences with hunger in the past month (e.g. have you ever gone to bed hungry?) and how often this occurred (often, sometimes, and rarely). Participants were given a score of 0 for responding No to the experiences questions, 1 if they responded rarely or sometimes to the frequency questions, and 2 if they responded often to the frequency questions. Participants were coded as having any household hunger if they had a score of ≥1.
Participants were also asked a series of questions regarding relationship practices, sexual behaviours and experiences of violence including: length of relationship (<12 months, 12-23 months, ≥24 months), ≥2 partners in the last 6 months (yes vs. no), and age-disparate partnership (≥5 years older). Participants were coded as ever having had transactional sex if they responded yes to the question “have you ever gave sex for money, goods, drugs, or alcohol?”. Participants who responded yes to having ever been physically hurt or threatened by a partner were coded as having experienced partner violence, and those that responded yes to “have you ever having been forced to have sex?” were coded as having experienced sexual violence.
Perceived HIV risk was assessed by asking participants “how much at risk do you think you are of becoming infected with HIV?” (not at all/Low risk vs. medium/high risk).
Statistical analysis
Descriptive statistics examined socio-demographic, behavioural, and relationship characteristics among young women who did and did not report effective contraception use in the last 6 months. We examined the overall and different types of contraception used among the three-level pregnancy variable. Descriptive statistics of where participants learned about contraception were reported among participants who responded to this question by pregnancy types. Baseline differences in socio-demographic factors between effective and ineffective contraceptive users were compared using Wilcoxon rank sum test for continuous variables and Pearson χ2 or Fisher’s exact test for categorical variables. A multivariable logistic regression analysis examined the independent association between adolescent pregnancy (vs. no pregnancy) and any pregnancy not as an adolescent (vs. no pregnancy) and effective contraception use, controlling for potential confounders (site, sexual orientation, and income). Confounders were chosen from a priori knowledge and selected into the model if p-value in bivariate associations was <0.30. Statistical analysis was conducted in Stata 13 (StataCorp. Stata Statistical Software: Release 13. 2013).12
Ethical considerations
All participants aged 18-24 years provided voluntary informed consent at enrollment. For participants aged 16-17 years, parents/legal guardians provided voluntary informed consent and the participant provided voluntary assent. Ethical approval was provided by the Research Ethics Board of Simon Fraser University, (2013S0114) the Human Research Ethics Committee (HREC) at the University of the Witwatersrand (M140707), and the Biomedical Research Ethics Committee at the University of KwaZulu-Natal granted reciprocity to the University of Witwatersrand HREC. Participants received a 150 ZAR (~$12 USD) reimbursement per visit to compensate for transportation costs and time.