M A J O R A R T I C L E
Incorporating Loss to Follow-up in Estimates of
Survival Among HIV-Infected Individuals in
Sub-Saharan Africa Enrolled in Antiretroviral
Stéphane Verguet,1Stephen S. Lim,1Christopher J. L. Murray,1Emmanuela Gakidou,1and Joshua A. Salomon2
1Institute for Health Metrics and Evaluation, University of Washington, Seattle; and2Department of Global Health and Population, Harvard School of
Public Health, Cambridge, Massachusetts
(See the editorial commentary by Hirschhorn and Pagano, on pages 4–5.)
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
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/mm3, 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.
Measuring the survival of human immunodeficiency virus–infected adult patients enrolled in
HIV treatment; antiretroviral therapy; survival; loss to follow-up; retention; cost-effectiveness;
In the last decade, under the leadership of the Global
Fund to Fight AIDS, Tuberculosis, and Malaria and
the United States President’s Emergency Plan for
AIDS Relief (PEPFAR), substantial scale-up of antire-
troviral therapy (ART) coverage has been achieved. An
estimated 300000 human immunodeficiency virus
(HIV)–infected people in low- and middle-income
countries were receiving ART in 2002, when the “3 by
5” initiative was launched, which aimed to have 3
million people receiving ART by 2005. The number of
people receiving ART rose to approximately 6.7
million by the end of 2010 . In sub-Saharan Africa,
an estimated 5.1 million people were receiving ART in
2010, which represented 49% coverage among those in
need of treatment in the region, according to World
Health Organization (WHO) eligibility criteria .
The monitoring of ART programs at the national
and regional level and the comparative evaluation of
performance across programs are essential activities
Received 31 January 2012; accepted 10 July 2012; electronically published 24
Correspondence: Stéphane Verguet, PhD, Department of Global Health, Univer-
sity of Washington, 325 9th Ave, Box 359931, Seattle, WA 98104 (verguet@uw.
The Journal of InfectiousDiseases2013;207:72–9
© The Author 2012. Published by Oxford University Press on behalf of the Infectious
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72 • JID 2013:207 (1 January) • Verguet et al
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