ArticleBritish journal of cancer2023
Immortal-time bias in older vs younger age groups: a simulation study with application to a population-based cohort of patients with colon cancer.
Article in British journal of cancer, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers, 1 of them a synthesis that pooled it.
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The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
11 citing papers in PubMed, 1 synthesis or guideline pooled it, 6 citations in OpenAlex.
- Epidemiology of Cancer in Older Adults: A Systematic Review.Current oncology reports · 2024Pooled it
- Target trial emulation studies in oncology: a comprehensive analysis.The oncologist · 2026Article
- Primary care physician documentation in oncology electronic health records: prognostic marker or immortal-time bias?ESMO real world data and digital oncology · 2026Article
- On the Statistical Limitations of Landmark Analysis for Addressing Immortal Time Bias.Statistics in medicine · 2026Article
- The Waiting Game: How NGS and Guideline-Concordant-Care Timing Shape Survival in Advanced NSCLC.Cancers · 2026Article
- Differential prognostic impact of liver resection by the site of concurrent extrahepatic diseases in patients with colorectal cancer liver metastases: a nationwide multicenter study (correspondence).International journal of surgery (London, England) · 2026Article
- Impact of diagnosis-to-treatment interval on mortality in patients with early-stage breast cancer: a retrospective nationwide Korean cohort.BMC women's health · 2025Article
- Addressing immortal time bias in precision medicine: Practical guidance and methods development.Health services research · 2025Article
- Medication Exposure and Mortality in Patients With Schizophrenia.JAMA network open · 2024Article
- Roles of circRNAs in the progression of colorectal cancer: novel strategies for detection and therapy.Cancer gene therapy · 2024Review
- Competing risks analysis of external versus internal radiation in patients with hepatocellular carcinoma after controlling for immortal time bias.Journal of cancer research and clinical oncology · 2023Article
Corrections and comments
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Authors and funding
4 authors at 2 institutions in 2 countries.
Funding
Abstract
backgroundIn observational studies, the risk of immortal-time bias (ITB) increases with the likelihood of early death, itself increasing with age. We investigated how age impacts the magnitude of ITB when estimating the effect of surgery on 1-year overall survival (OS) in patients with Stage IV colon cancer aged 50-74 and 75-84 in England.
methodsUsing simulations, we compared estimates from a time-fixed exposure model to three statistical methods addressing ITB: time-varying exposure, delayed entry and landmark methods. We then estimated the effect of surgery on OS using a population-based cohort of patients from the CORECT-R resource and conducted the analysis using the emulated target trial framework.
resultsIn simulations, the magnitude of ITB was larger among older patients when their probability of early death increased or treatment was delayed. The bias was corrected using the methods addressing ITB. When applied to CORECT-R data, these methods yielded a smaller effect of surgery than the time-fixed exposure approach but effects were similar in both age groups.
conclusionITB must be addressed in all longitudinal studies, particularly, when investigating the effect of exposure on an outcome in different groups of people (e.g., age groups) with different distributions of exposure and outcomes.
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