title: Treatment outcomes of HIV-positive patients on first-line antiretroviral therapy in private versus public HIV clinics in Johannesburg, South Africa.
abstract: BACKGROUND
  Despite the widely documented success of antiretroviral therapy (ART), stakeholders continue to face the challenges of poor HIV treatment outcomes. While many studies have investigated patient-level causes of poor treatment outcomes, data on the effect of health systems on ART outcomes are scarce.
  
  
  OBJECTIVE
  We compare treatment outcomes among patients receiving HIV care and treatment at a public and private HIV clinic in Johannesburg, South Africa.
  
  
  METHODS
  This was a retrospective cohort analysis of ART naïve adults (≥18.0 years), initiating ART at a public or private clinic in Johannesburg between July 01, 2007 and December 31, 2012. Cox proportional-hazards regression was used to identify baseline predictors of mortality and loss to follow-up (>3 months late for the last scheduled visit). Generalized estimating equations were used to determine predictors of failure to suppress viral load (≥400 copies/mL) while the Wilcoxon rank-sum test was used to compare the median absolute change in CD4 count from baseline to 12 months post-ART initiation.
  
  
  RESULTS
  12,865 patients initiated ART at the public clinic compared to 610 at the private clinic. The patients were similar in terms of sex and age at initiation. Compared to public clinic patients, private clinic patients initiated ART at higher median CD4 counts (159 vs 113 cells/mm(3)) and World Health Organization stage I/II (76.1% vs 58.5%). Adjusted hazard models showed that compared to public clinic patients, private clinic patients were less likely to die (adjusted hazard ratio [aHR] 0.50; 95% confidence interval [CI] 0.35-0.70) but were at increased risk of loss to follow-up (aHR 1.80; 95% CI 1.59-2.03). By 12 months post-ART initiation, private clinic patients were less likely to have a detectable viral load (adjusted relative risk 0.65; 95% CI 0.49-0.88) and recorded higher median CD4 change from baseline (184 cells/mm(3) interquartile range 101-300 vs 158 cells/mm(3) interquartile range 91-244), when compared to public clinic patients.
  
  
  CONCLUSIONS
  We identified differences in treatment outcomes between the two HIV clinics. Findings suggest that the type of clinic at which ART patients initiate and receive treatment can have an impact on treatment outcomes. Further research is necessary to provide more conclusive results.
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Faith
authors.initials: F
authors.lastname: Moyo
authors.affiliation: Epidemiology and Biostatistics Department, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Epidemiology and Strategic Information (ESI), HIV/AIDS/STIs and TB, Human Sciences Research Council, Pretoria, South Africa.
authors.forename: Charles
authors.initials: C
authors.lastname: Chasela
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Center for Global Health and Development, Boston University, Boston, MA, USA.
authors.forename: Alana T
authors.initials: AT
authors.lastname: Brennan
authors.affiliation: Brenthurst Clinic, Parktown, South Africa.
authors.forename: Osman
authors.initials: O
authors.lastname: Ebrahim
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Right to Care, Helen Joseph Hospital, Westdene, Johannesburg, South Africa.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Sanne
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Long
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Denise
authors.initials: D
authors.lastname: Evans
keywords: HIV programs; attrition; health systems; viral suppression