Using national laboratory data to assess cumulative frequency of linkage after transfer to community-based HIV clinics in South Africa

INTRODUCTION: Changes to the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) funding have led to closures of non-governmental HIV clinics with patient transfers to government-funded clinics. We sought to determine the success of transfers in South Africa using a national data source. METHODS: All adults (≥18 years) on antiretroviral therapy (ART) who visited a single PEPFAR-funded hospital-based HIV clinic in Durban, South Africa from March to June 2012 were transferred to community-based clinics. Previously, we matched patient records from the hospital-based HIV clinic with National Health Laboratory Services (NHLS) Corporate Data Warehouse (CDW) data to estimate the proportion of patients with a CD4 count or viral load (VL) in the CDW during the year before transfer. As a proxy for retention in care, in this study we evaluated whether patients had a CD4 count or VL at another facility within approximately three years of transfer. Patients referred to a private doctor at transfer were excluded from the analysis. We assessed predictors (age, sex, CD4 count, VL status, ART duration and location of future care) of not having post-transfer laboratory data using Cox proportional hazards models. RESULTS: Of the 3893 patients referred to a government facility at transfer, 41% were male and median age was 39 years (IQR 34 to 46). There was a post-transfer CD4 count or VL from another facility for 23% of these individuals within six months, 44% within one year, 57% within two years and 61% within approximately three years. Male sex (aHR 1.20, 95% CI 1.10 to 1.31) and shorter duration on ART ( 1 year) were associated with not having a post-transfer record. CONCLUSIONS: Using data from the NHLS CDW, 61% of patients had evidence of a post-transfer laboratory record at another facility within approximately three years after closure of a large South African HIV clinic. Males and those with shorter time on ART prior to transfer were at highest risk for lacking follow-up laboratory data. As patients transfer care, national data sources can be used to evaluate long-term patient care trajectories.