Loss to Follow-up in the Hepatitis C Care Cascade: A Substantial Problem but Opportunity for Micro-elimination

A Substantial Problem But Opportunity for Micro-elimination

Marleen van Dijk; Joost P.H. Drenth


J Viral Hepat. 2020;27(12):1270-1283. 

In This Article

Concept of Loss to Follow-up

Different definitions for LTFU are used in the literature, since patients become lost to follow-up for various reasons. For example, they may have moved house, emigrated, died or been imprisoned. Many times, the reason for LTFU cannot be ascertained as contact with the patient cannot be established. Retrospective observational studies often do not provide a specific definition or use nonattendance to any appointment as a definition.Suppl file 1–11 Some of these studies mention death separately and do not include this as a reason for LTFU.Suppl file 12–17 Other studies that reviewed ever-diagnosed patients defined LTFU as patients who never or not recently had an appointment with an HCV specialist.Suppl file 18,19 Interventional studies aiming to improve the cascade of care also do not give a definition or define LTFU as nonattendance anywhere in the care cascade,Suppl file 20–49 often separating death from the LTFU group.Suppl file 50–58 There are some studies that include multiple LTFU definitions and report data on all of them, such as nonattendance, nonresponse to invitation, moved, incarcerated, no insurance and comorbidities.Suppl file 59–62

There may be a lesson to be learned on defining LTFU from studies in other fields of medicine. Previously mentioned HCV studies did not take time into account when defining LTFU. Prospective studies defined LTFU as nonattendance at the end of their study period, which varied greatly among studies. Retrospective studies defined LTFU as nonattendance since their last visit up to study initiation. HIV studies have investigated LTFU extensively and showed that the way you define LTFU greatly influences your LTFU outcomes.[7] In addition, these studies have demonstrated different ways to determine the ideal timeframe to classify someone as LTFU, that is x days after last clinic visit.[8,9] When different studies use different definitions, it is virtually impossible to compare care cascades and combine results. However, since this is the case for the HCV studies assessed in this review, we chose a pragmatic approach that suits the illustrative purpose of this review. We define LTFU as nonattendance to any appointment in the care cascade at any time since their last visit. Patients who had died were not included in the definition of LTFU.