Identifying, handling and impact of immortal time bias on addressing treatment effects in observational studies using routinely collected data.

ABSTRACT:

Background

Immortal time bias (ITB) represents a methodological challenge in evaluating treatment effects in observational studies using routinely collected data (RCD). However, the prevalence of ITB, the strategies used to address ITB and its impact remain inadequate. This study aimed to investigate how ITB was identified and handled in observational studies using RCD, and to assess its impact on treatment effect estimates.

Methods

A systematic search was performed in PubMed for observational studies published from 2018 to 2020 that used RCD to evaluate drug treatment effects. We examined the synchronization of three time points (eligibility, treatment assignment, and the start of follow-up) to identify ITB and assessed the risk of ITB. For low-risk studies, we summarized t

SUBMITTER: Xie S 

PROVIDER: S-EPMC12801502 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature