Universal definition of loss to follow-up in HIV treatment programs: A statistical analysis of 111 facilities in Africa, Asia, and Latin America

Benjamin H. Chi, Constantin Yiannoutsos, Andrew O. Westfall, Jamie E. Newman, Jialun Zhou, Carina Cesar, Martin W G Brinkhof, Albert Mwango, Eric Balestre, Gabriela Carriquiry, Thira Sirisanthana, Henri Mukumbi, Jeffrey N. Martin, Anna Grimsrud, Melanie Bacon, Rodolphe Thiebaut

Research output: Contribution to journalArticle

103 Citations (Scopus)

Abstract

Background: Although patient attrition is recognized as a threat to the long-term success of antiretroviral therapy programs worldwide, there is no universal definition for classifying patients as lost to follow-up (LTFU). We analyzed data from health facilities across Africa, Asia, and Latin America to empirically determine a standard LTFU definition. Methods and Findings: At a set "status classification" date, patients were categorized as either "active" or "LTFU" according to different intervals from time of last clinic encounter. For each threshold, we looked forward 365 d to assess the performance and accuracy of this initial classification. The best-performing definition for LTFU had the lowest proportion of patients misclassified as active or LTFU. Observational data from 111 health facilities-representing 180,718 patients from 19 countries-were included in this study. In the primary analysis, for which data from all facilities were pooled, an interval of 180 d (95% confidence interval [CI]: 173-181 d) since last patient encounter resulted in the fewest misclassifications (7.7%, 95% CI: 7.6%-7.8%). A secondary analysis that gave equal weight to cohorts and to regions generated a similar result (175 d); however, an alternate approach that used inverse weighting for cohorts based on variance and equal weighting for regions produced a slightly lower summary measure (150 d). When examined at the facility level, the best-performing definition varied from 58 to 383 d (mean = 150 d), but when a standard definition of 180 d was applied to each facility, only slight increases in misclassification (mean = 1.2%, 95% CI: 1.0%-1.5%) were observed. Using this definition, the proportion of patients classified as LTFU by facility ranged from 3.1% to 45.1% (mean = 19.9%, 95% CI: 19.1%-21.7%). Conclusions: Based on this evaluation, we recommend the adoption of ≥180 d since the last clinic visit as a standard LTFU definition. Such standardization is an important step to understanding the reasons that underlie patient attrition and establishing more reliable and comparable program evaluation worldwide. Please see later in the article for the Editors' Summary.

Original languageEnglish
Article numbere1001111
JournalPLoS Medicine
Volume8
Issue number10
DOIs
StatePublished - Oct 2011

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Latin America
Lost to Follow-Up
HIV
Confidence Intervals
Health Facilities
Therapeutics
Program Evaluation
Ambulatory Care
Weights and Measures

ASJC Scopus subject areas

  • Medicine(all)

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Universal definition of loss to follow-up in HIV treatment programs : A statistical analysis of 111 facilities in Africa, Asia, and Latin America. / Chi, Benjamin H.; Yiannoutsos, Constantin; Westfall, Andrew O.; Newman, Jamie E.; Zhou, Jialun; Cesar, Carina; Brinkhof, Martin W G; Mwango, Albert; Balestre, Eric; Carriquiry, Gabriela; Sirisanthana, Thira; Mukumbi, Henri; Martin, Jeffrey N.; Grimsrud, Anna; Bacon, Melanie; Thiebaut, Rodolphe.

In: PLoS Medicine, Vol. 8, No. 10, e1001111, 10.2011.

Research output: Contribution to journalArticle

Chi, BH, Yiannoutsos, C, Westfall, AO, Newman, JE, Zhou, J, Cesar, C, Brinkhof, MWG, Mwango, A, Balestre, E, Carriquiry, G, Sirisanthana, T, Mukumbi, H, Martin, JN, Grimsrud, A, Bacon, M & Thiebaut, R 2011, 'Universal definition of loss to follow-up in HIV treatment programs: A statistical analysis of 111 facilities in Africa, Asia, and Latin America', PLoS Medicine, vol. 8, no. 10, e1001111. https://doi.org/10.1371/journal.pmed.1001111
Chi, Benjamin H. ; Yiannoutsos, Constantin ; Westfall, Andrew O. ; Newman, Jamie E. ; Zhou, Jialun ; Cesar, Carina ; Brinkhof, Martin W G ; Mwango, Albert ; Balestre, Eric ; Carriquiry, Gabriela ; Sirisanthana, Thira ; Mukumbi, Henri ; Martin, Jeffrey N. ; Grimsrud, Anna ; Bacon, Melanie ; Thiebaut, Rodolphe. / Universal definition of loss to follow-up in HIV treatment programs : A statistical analysis of 111 facilities in Africa, Asia, and Latin America. In: PLoS Medicine. 2011 ; Vol. 8, No. 10.
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abstract = "Background: Although patient attrition is recognized as a threat to the long-term success of antiretroviral therapy programs worldwide, there is no universal definition for classifying patients as lost to follow-up (LTFU). We analyzed data from health facilities across Africa, Asia, and Latin America to empirically determine a standard LTFU definition. Methods and Findings: At a set {"}status classification{"} date, patients were categorized as either {"}active{"} or {"}LTFU{"} according to different intervals from time of last clinic encounter. For each threshold, we looked forward 365 d to assess the performance and accuracy of this initial classification. The best-performing definition for LTFU had the lowest proportion of patients misclassified as active or LTFU. Observational data from 111 health facilities-representing 180,718 patients from 19 countries-were included in this study. In the primary analysis, for which data from all facilities were pooled, an interval of 180 d (95{\%} confidence interval [CI]: 173-181 d) since last patient encounter resulted in the fewest misclassifications (7.7{\%}, 95{\%} CI: 7.6{\%}-7.8{\%}). A secondary analysis that gave equal weight to cohorts and to regions generated a similar result (175 d); however, an alternate approach that used inverse weighting for cohorts based on variance and equal weighting for regions produced a slightly lower summary measure (150 d). When examined at the facility level, the best-performing definition varied from 58 to 383 d (mean = 150 d), but when a standard definition of 180 d was applied to each facility, only slight increases in misclassification (mean = 1.2{\%}, 95{\%} CI: 1.0{\%}-1.5{\%}) were observed. Using this definition, the proportion of patients classified as LTFU by facility ranged from 3.1{\%} to 45.1{\%} (mean = 19.9{\%}, 95{\%} CI: 19.1{\%}-21.7{\%}). Conclusions: Based on this evaluation, we recommend the adoption of ≥180 d since the last clinic visit as a standard LTFU definition. Such standardization is an important step to understanding the reasons that underlie patient attrition and establishing more reliable and comparable program evaluation worldwide. Please see later in the article for the Editors' Summary.",
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AU - Newman, Jamie E.

AU - Zhou, Jialun

AU - Cesar, Carina

AU - Brinkhof, Martin W G

AU - Mwango, Albert

AU - Balestre, Eric

AU - Carriquiry, Gabriela

AU - Sirisanthana, Thira

AU - Mukumbi, Henri

AU - Martin, Jeffrey N.

AU - Grimsrud, Anna

AU - Bacon, Melanie

AU - Thiebaut, Rodolphe

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N2 - Background: Although patient attrition is recognized as a threat to the long-term success of antiretroviral therapy programs worldwide, there is no universal definition for classifying patients as lost to follow-up (LTFU). We analyzed data from health facilities across Africa, Asia, and Latin America to empirically determine a standard LTFU definition. Methods and Findings: At a set "status classification" date, patients were categorized as either "active" or "LTFU" according to different intervals from time of last clinic encounter. For each threshold, we looked forward 365 d to assess the performance and accuracy of this initial classification. The best-performing definition for LTFU had the lowest proportion of patients misclassified as active or LTFU. Observational data from 111 health facilities-representing 180,718 patients from 19 countries-were included in this study. In the primary analysis, for which data from all facilities were pooled, an interval of 180 d (95% confidence interval [CI]: 173-181 d) since last patient encounter resulted in the fewest misclassifications (7.7%, 95% CI: 7.6%-7.8%). A secondary analysis that gave equal weight to cohorts and to regions generated a similar result (175 d); however, an alternate approach that used inverse weighting for cohorts based on variance and equal weighting for regions produced a slightly lower summary measure (150 d). When examined at the facility level, the best-performing definition varied from 58 to 383 d (mean = 150 d), but when a standard definition of 180 d was applied to each facility, only slight increases in misclassification (mean = 1.2%, 95% CI: 1.0%-1.5%) were observed. Using this definition, the proportion of patients classified as LTFU by facility ranged from 3.1% to 45.1% (mean = 19.9%, 95% CI: 19.1%-21.7%). Conclusions: Based on this evaluation, we recommend the adoption of ≥180 d since the last clinic visit as a standard LTFU definition. Such standardization is an important step to understanding the reasons that underlie patient attrition and establishing more reliable and comparable program evaluation worldwide. Please see later in the article for the Editors' Summary.

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