Retention and predictors of attrition among patients who started antiretroviral therapy in Zimbabwe's national antiretroviral therapy programme between 2012 and 2015

BACKGROUND: The last evaluation to assess outcomes for patients receiving antiretroviral therapy (ART) through the Zimbabwe public sector was conducted in 2011, covering the 2007-2010 cohorts. The reported retention at 6, 12, 24 and 36 months were 90.7%, 78.1%, 68.8% and 64.4%, respectively. We report findings of a follow-up evaluation for the 2012-2015 cohorts to assess the implementation and impact of recommendations from this prior evaluation.

METHODS: A nationwide retrospective study was conducted in 2016. Multi-stage proportional sampling was used to select health facilities and study participants records. The data extracted from patient manual records included demographic, baseline clinical characteristics and patient outcomes (active on treatment, died, transferred out, stopped ART and lost to follow-up (LTFU)) at 6, 12, 24 and 36 months. The data were analysed using Stata/IC 14.2. Retention was estimated using survival analysis. The predictors associated with attrition were determined using a multivariate Cox regression model.

RESULTS: A total of 3,810 participants were recruited in the study. The median age in years was 35 (IQR: 28-42). Overall, retention increased to 92.4% (p-value = 0.060), 86.5% (p-value<0.001), 79.2% (p-value<0.001) and 74.4% (p-value<0.001) at 6, 12, 24 and 36 months respectively. LTFU accounted for 98% of attrition. Being an adolescent or a young adult (15-24 years) (vs adult;1.41; 95% CI:1.14-1.74), children (<15years) (vs adults; aHR 0.64; 95% CI:0.46-0.91), receiving care at primary health care facility (vs central and provincial facility; aHR 1.23; 95% CI:1.01-1.49), having initiated ART between 2014-2015 (vs 2012-2013; aHR1.45; 95%CI:1.24-1.69), having WHO Stage IV (vs Stage I-III; aHR2.06; 95%CI:1.51-2.81) and impaired functional status (vs normal status; aHR1.25; 95%CI:1.04-1.49) predicted attrition.

CONCLUSION: The overall retention was higher in comparison to the previous 2007-2010 evaluation. Further studies to understand why attrition was found to be higher at primary health care facilities are warranted. Implementation of strategies for managing patients with advanced HIV disease, differentiated care for adolescents and young adults and tracking of LTFU clients should be prioritised to further improve retention.