Do Increasing Rates of Loss to Follow-up in Antiretroviral Treatment Programs Imply Deteriorating Patient Retention?

Johnson, Leigh F; Estill, Janne; Keiser, Olivia; Cornell, Morna; Moolla, Haroon; Schomaker, Michael; Grimsrud, Anna; Davies, Mary-Ann; Boulle, Andrew (2014). Do Increasing Rates of Loss to Follow-up in Antiretroviral Treatment Programs Imply Deteriorating Patient Retention? American journal of epidemiology, 180(12), pp. 1208-12. Oxford University Press 10.1093/aje/kwu295

[img] Text
Johnson AmJEpidmiol 2014.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (315kB) | Request a copy

In several studies of antiretroviral treatment (ART) programs for persons with human immunodeficiency virus infection, investigators have reported that there has been a higher rate of loss to follow-up (LTFU) among patients initiating ART in recent years than among patients who initiated ART during earlier time periods. This finding is frequently interpreted as reflecting deterioration of patient retention in the face of increasing patient loads. However, in this paper we demonstrate by simulation that transient gaps in follow-up could lead to bias when standard survival analysis techniques are applied. We created a simulated cohort of patients with different dates of ART initiation. Rates of ART interruption, ART resumption, and mortality were assumed to remain constant over time, but when we applied a standard definition of LTFU, the simulated probability of being classified LTFU at a particular ART duration was substantially higher in recently enrolled cohorts. This suggests that much of the apparent trend towards increased LTFU may be attributed to bias caused by transient interruptions in care. Alternative statistical techniques need to be used when analyzing predictors of LTFU-for example, using "prospective" definitions of LTFU in place of "retrospective" definitions. Similar considerations may apply when analyzing predictors of LTFU from treatment programs for other chronic diseases.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Social and Preventive Medicine

UniBE Contributor:

Estill, Janne Anton Markus and Keiser, Olivia


600 Technology > 610 Medicine & health
300 Social sciences, sociology & anthropology > 360 Social problems & social services




Oxford University Press




Doris Kopp Heim

Date Deposited:

20 Nov 2014 14:59

Last Modified:

20 Jan 2015 15:19

Publisher DOI:


PubMed ID:


Uncontrolled Keywords:

HIV, acquired immunodeficiency syndrome, antiretroviral treatment, loss to follow-up, survival analysis




Actions (login required)

Edit item Edit item
Provide Feedback