Date of Award

January 2017

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Gerald Friedland



Retention in care is an essential component of meeting the UNAIDS “90-90-90” HIV treatment targets. In Khayelitsha township (population ~500,000) in Cape Town, South Africa, more than 50,000 patients have received ART since the inception of this public sector program in 2001. Disengagement from care remains an important challenge. We sought to determine the incidence of and risk factors associated with disengagement from care in 2013-4, and outcomes for those who disengaged.


We conducted a retrospective cohort study of all patients >= ten years of age who visited one of the 13 Khayelitsha ART clinics in 2013-14 regardless of the date they initiated ART. We described the cumulative incidence of first disengagement (>180 days) between 1 Jan 2013- 31 Dec 2014 by time on ART and time in the study using a competing risks model, which enabled us to extrapolate disengagement incidence up to ten years after ART initiation. We also described risk factors for disengagement based on a Cox proportional hazards model. We ascertained outcomes (death, return to care, hospital admission, other hospital contact, alive but not in care, no information) after disengagement until 30 June 2015 using province-wide health databases and the National Death Registry.


Of 39,884 patients meeting our eligibility criteria, the median time on ART to 31 December 2014 was 33.6 months (IQR 12.4-63.2). Of the total study cohort, 592 (1.5%) died in the study period, 1,231 (3.1%) formally transferred out, 987 (2.5%) were “silent transfers” and visited another provincial clinic within 180 days, 9,005 (22.6%) disengaged, and 28,069 (70.4%) remained “in care.” Cumulative incidence of disengagement from care was 25.1% by five years on ART and 37.7% by ten years on ART estimated from time contributed in the study window in the competing risks model. Key factors associated with disengagement were age <30 years (10-20 years HR 1.38, 95% CI 1.24-1.54; 20-30 years HR 1.46, 95% CI 1.38-1.54; both relative to reference 30-40 years), male sex, pregnancy at ART start, and last CD4 count <350 cells/μl (CD4 <50 HR 3.34, 95% CI 2.92-3.83; CD4 50-200 HR 3.07, 95% CI 2.84-3.31; CD4 200-350 HR 2.03, 95% CI 1.91-2.15, all relative to reference CD4 >350 cells/μl); protective factors were ART club membership and baseline CD4 <350 cells/μl (CD4<50 HR 0.39, 95% CI 0.35-0.44; CD4 50-200 HR 0.46, 95% CI 0.43-0.50; CD4 200-350 HR 0.6, 95% CI 0.56-0.65, all relative to reference CD4 > 350 cells/μl) (Table 1). Of those who disengaged, the two most common outcomes by 30 June 2015 were return to ART care after 180 days (33%), and being alive but not in care in the Western Cape (25%). After disengagement, a total of 1,459 (16.2%) patients were hospitalized and 237 (2.6%) died.


One quarter of patients in Khayelitsha, one of the longest running ART programs in South Africa, disengaged from ART care at least once in a contemporary two-year period. One key aspect of the HIV care cascade is retention in care. While the majority of patients either subsequently returned to care or remained alive without hospitalization, a challenge to meeting retention targets, and the broader 90-90-90 HIV treatment targets, is developing, testing, and implementing program designs to target mobile populations and retain them in lifelong care. This should be guided by risk factors for disengagement as observed in this and other studies. Additionally, some focus should be placed on preventing misclassification of patients with regards to retention status by utilizing better patient tracking systems.


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