title: Incorporating loss to follow-up in estimates of survival among HIV-infected individuals in sub-Saharan Africa enrolled in antiretroviral therapy programs.
abstract: BACKGROUND
  Measuring the survival of human immunodeficiency virus-infected adult patients enrolled in antiretroviral therapy (ART) programs is complicated by short observation periods and loss to follow-up. We synthesized data from treatment cohorts in sub-Saharan Africa to estimate survival over 5 years after initiation of ART.
  
  
  METHODS
  We used data on retention, mortality, and loss to follow-up from 34 cohorts, including a total of 102,306 adult patients from 18 sub-Saharan African countries. These data were augmented by data from 13 sub-Saharan African studies tracking death rates among adult patients who were lost to follow-up (LTFU). We used a Poisson regression model to estimate survival over time, incorporating predicted mortality among LTFU patients.
  
  
  RESULTS
  Across studies, the median CD4(+) cell count at ART initiation was 104 cells/mm(3), 65% of patients were female, and the median age was 37 years. Survival at 1 year and 5 years were estimated to be 0.87 (95% confidence interval [CI], 0.72-0.94) and 0.70 (95% CI, 0.36-0.86), respectively, after adjustment for loss to follow-up. The life-years gained by a patient during the 5-year period after starting ART were estimated at 2.1 (95% CI, 1.6-2.3) in the adjusted model, compared with 1.7 (95% CI, 1.1-2.0) if there was 100% mortality among LTFU patients and with 2.4 (1.7-2.7) if there was 0% mortality among LTFU patients.
  
  
  CONCLUSIONS
  Accounting for loss to follow-up produces substantial changes in the estimated life-years gained during the first 5 years of ART receipt.
authors.affiliation: Department of Global Health, Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA 98104, USA. verguet@uw.edu
authors.forename: Stéphane
authors.initials: S
authors.lastname: Verguet
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Lim
authors.forename: Christopher J L
authors.initials: CJ
authors.lastname: Murray
authors.forename: Emmanuela
authors.initials: E
authors.lastname: Gakidou
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Salomon
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D003362:Cost-Benefit Analysis; D003695:Delivery of Health Care; D005260:Female; D006678:HIV / Q000187:drug effects*; D015658:HIV Infections / Q000188:drug therapy* / Q000401:mortality* / Q000821:virology; D006801:Humans; D059012:Lost to Follow-Up; D008297:Male; D010349:Patient Compliance; D012044:Regression Analysis; D016019:Survival Analysis
chemical_list: D019380:Anti-HIV Agents