Objective: Adolescent antiretroviral treatment (ART) adherence remains critically low. We lack research testing protective factors across both clinic and care environments. Design: A prospective cohort of adolescents living with HIV (sample n = 969, 55% girls, baseline mean age 13.6) in the Eastern Cape Province in South Africa were interviewed at baseline and 18-month follow-up (2014-2015, 2015-2016). We traced all adolescents ever initiated on treatment in 52 government health facilities (90% uptake, 93% 18-month retention, 1.2% mortality). Methods: Clinical records were collected; standardized questionnaires were administered by trained data collectors in adolescents’ language of choice. Probit within-between regressions and average adjusted probability calculations were used to examine associations of caregiving and clinic factors with adherence, controlling for household structure, socioeconomic and HIV factors. Results: Past-week ART adherence was 66% (baseline), 65% (follow-up), validated against viral load in subsample. Within-individual changes in three factors were associated with improved adherence: no physical and emotional violence (12.1 percentage points increase in adjusted probability of adherence, P < 0.001), improvement in perceived healthcare confidentiality (7.1 percentage points, P < 0.04) and shorter travel time to the clinic (13.7 percentage points, P < 0.02). In combination, improvement in violence prevention, travel time and confidentiality were associated with 81% probability of ART adherence, compared with 47% with a worsening in all three. Conclusion: Adolescents living with HIV need to be safe at home and feel safe from stigma in an accessible clinic. This will require active collaboration between health and child protection systems, and utilization of effective violence prevention interventions.
The study took place in the Eastern Cape province of South Africa, characterized by high morbidity, low human development and poor infrastructure. We conducted standardized interviews and extracted clinical records for 1046 adolescents living with HIV at baseline (2014–2015), with 979 reinterviewed at 18-month follow-up (2016–2017). Nine hundred and sixty-nine had complete data on key variables. The study included both adolescents engaged in clinical care and those who were lost to follow-up in clinical care, and thus, it is the region's first large-scale community-traced cohort of this group. In a health district including rural, urban and peri-urban settlements, we identified all 52 community health centres, primary clinics and hospitals that provided ART to adolescents. In each facility, all patient files (paper and electronic) were reviewed to identify all those who had ever initiated ART and were aged 10–19 years. Throughout 180 communities, adolescents were interviewed at a location of their choice. At 18 months after baseline, all adolescents who had consented to be reapproached were asked for consent for follow-up. Reflecting high mobility, 18% of participants have moved households between study waves, and by follow-up participants lived in six provinces: Eastern Cape, Gauteng, KwaZulu-Natal, Free State, Western Cape and North-West. Ethical approvals were given by the University of Cape Town (CSSR 2013/4), Oxford University (CUREC2/12–21), provincial Departments of Health and Education, and healthcare facilities. All adolescents and their primary caregivers gave written informed consent at both time points in their language of choice (Xhosa or English), read aloud in cases of low literacy. The study did not provide financial incentives, but adolescents did receive a snack, a certificate of participation, and a small gift pack including soap and pencils. These were recommended by our adolescent advisory group [30] and provided regardless of interview completion. Clinical records were extracted in healthcare facilities (see Supplementary Materials Box S1), and trained local researchers supported participants in completing tablet-based questionnaires lasting 60–90 min. Adolescents chose their language of participation. Questionnaires were codesigned with an adolescent advisory group; the South African National Departments of Health, Social Development, Basic Education and National AIDS Council; UNICEF; PEPFAR-USAID, and local NGOs. Prepiloting was conducted locally with 25 adolescents living with HIV. To avoid stigma or unintended disclosure of HIV status, the research focus was presented as general adolescent social and health needs, and 456 neighbouring adolescents were also interviewed (not included in these analyses). Confidentiality was maintained except in cases of risk of harm. For rape, abuse, suicidality or untreated severe illness [e.g. symptomatic tuberculosis (TB)], researchers made immediate health and social service referrals with follow-up support (n = 157 referrals over 3 years for 104 adolescents). Full questionnaires are available at http://www.youngcarers.org.za/youthpulse. All variables in these analyses were measured and defined in the same way at baseline and follow-up. ART adherence was measured using adapted items from the Patient Medication Adherence Questionnaire and measures developed in Botswana [31,32]. ART adherence was defined as past 7 days adherence more than 95% (including weekdays and weekend), based on currently taking ART and not having missed any doses in the past seven days [33]. We validated self-reported adherence against viral loads available in clinical records, using the viral load measurement closest to the interview date. Eight percent of adolescents’ clinical records did not include any viral load measurements, and about 60% of adolescents with an available viral load had a measurement from the two years before or after the questionnaire date [34]. Thus, our validation focused on adolescents whose clinical records included viral load measurements within this period, excluding measurements in a 30-day range around ART initiation (n = 650 adolescents at baseline and n = 598 at follow-up). Clinic factors: Medication stock-outs were measured as past-year inability to access ART due to clinic stock-outs. Confidentiality was measured as feeling that their information would be kept safe and confidential at the clinic most or all of the time in the past year. Wait time in the clinic above 1 h and travel to the clinic above 1 h were measured as past-year experiences in respect to the main clinic the adolescent attends [27–29]. Caregiving factors: Past-year physical or emotional abuse victinization by caregivers or other adults were measured using UNICEF Measures for National-level Monitoring of Orphans and Vulnerable Children [35] (12 items) and defined as having experienced at least one type of violence, such as being hit with a hard item. Past-week witnessing domestic violence between adults in the home (physical or verbal) also used these UNICEF measures [35] (two items). Good parent/caregiver monitoring and supervision (nine items, e.g., having rules for when adolescents come home) and positive caregiving (six items, e.g. positive reinforcement) were measured over the past 2 months, using subscales of the Alabama Parenting Questionnaire [36], and defined as not having experienced any poor monitoring and supervision, and as always experiencing positive caregiving. Good communication between primary caregivers and adolescents was measured over the past 2 months using adapted Child-Parent Communication Apprehension Scale for use with young adults, asking about ease and openness of communication and defined as agreeing or strongly agreeing to all items (five items) [37]. All caregiving and clinic factors were dichotomized to facilitate interpretability. Household structure factors included orphanhood (maternal or paternal) measured using items adapted from the 2011 South African census [38]; number of changes of caregiver experienced; household size, and relationship of primary caregiver to child, that is biological parent or not. Socioeconomic factors included adolescent age, sex, urban/rural location and living in formal or informal housing, using census-based items [39]. Household poverty was measured as access to eight highest socially perceived necessities for children in the nationally representative South African Social Attitudes Survey (e.g. enough food) [40]. HIV-related factors were measured using clinical records, checked against self-report where possible, and included mode of HIV infection (vertical/horizontal) and recent HIV infection (<2 years before baseline). First, we validated self-reported ART adherence against undetectable viral load (<50 copies/ml) from clinical records using multivariable logistic regression, controlling for age, sex, rural/urban, orphanhood, informal housing, mode of infection and health status. Second, we examined frequencies of adherence, hypothesized explanatory and control variables. Third, we compared participants who were followed up and included in this analysis, and those who were not, to check for potential differences using t-tests for continuous variables and Chi-squared tests for dichotomous variables. Fourth, we examined associations of clinic and care factors with past-week adherence. We used a within-between regression model, also known as a hybrid model, which allows us to look at within-person variation as well as compute average adjusted probabilities of the outcome [41–43]. For each explanatory variable, we used a person's average value and time-specific deviation from this average [see Eq. (1)]. where Φ is the cumulative normal distribution, adherence is the time-varying dependent variable, β0 represents the overall intercept, xit is a time-varying explanatory variable for person i at time t,x¯i is the average of the explanatory variable for person i across both time points, β1 represents the average between-person effect and β2 represents the average within-person effect, vi0 – a random person-level intercept, assumed to be normally distributed, and εit – the residuals. This provides a ‘between-person’ coefficient (estimated by x¯i), the difference between individuals and a ‘within-person’ coefficient (estimated by xit−x¯i), which examines the changes within individual's levels of the explanatory variable over time. With two time points, the within-person estimate is equivalent to a first difference model [44]. The within-person estimate is the focus of our analyses as it allows to account for all time-invariant confounders [44]. Participant sex, ART initiation and mode of infection were modelled as time-invariant, while all other control variables were modelled as time-variant. Analyses were conducted in Stata 14.2 (code available at https://osf.io/znse9/). We used a probit model (xtprobit command) with robust clustered standard errors at the individual level. To aid interpretation of the relationships between the explanatory variables and adherence, we estimated average adjusted probabilities [45] of the clinic and caregiving factors that were statistically significant in the multivariable regression (P < 0.05), using margins and lincom commands [46].