ArticleHealth services research2020
Resurrecting immortal-time bias in the study of readmissions.
Article in Health services research, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
5 citing papers in PubMed.
- Addressing immortal time bias in precision medicine: Practical guidance and methods development.Health services research · 2025Article
- Robotic-assisted reoperative ileal pouch-anal anastomosis: robotic pouch excision and pouch revision.Techniques in coloproctology · 2024Article
- Discordance in Published 30-Day Readmission Rates Following Primary Total Hip and Total Knee Arthroplasty: Centers for Medicare and Medicaid Services (CMS) Versus the National Surgical Quality Improvement Program (NSQIP).The Iowa orthopaedic journal · 2024Article
- Immortal Time Bias in the Analysis of Time-to-Event Data in Orthopedics.The Journal of arthroplasty · 2021Article
- Resurrecting immortal-time bias in the study of readmissions.Health services research · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
Abstract
objectiveTo compare readmission rates as measured by the Centers for Medicare and Medicaid Services and the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) methods. DATA SOURCES: 20 percent sample of national Medicare data for patients undergoing cystectomy, colectomy, abdominal aortic aneurysm (AAA) repair, and total knee arthroplasty (TKA) between 2010 and 2014. STUDY
designRetrospective cohort study comparing 30-day readmission rates. DATA COLLECTION/EXTRACTION
methodsPatients undergoing cystectomy, colectomy, abdominal aortic aneurysm repair, and total knee arthroplasty between 2010 and 2014 were identified. PRINCIPAL
findingsCystectomy had the highest and total knee arthroplasty had the lowest readmission rate. The NSQIP measure reported significantly lower rates for all procedures compared to the CMS measure, which reflects an immortal-time bias.
conclusionsWe found significantly different readmission rates across all surgical procedures when comparing CMS and NSQIP measures. Longer length of stay exacerbated these differences. Uniform outcome measures are needed to eliminate ambiguity and synergize research and policy efforts.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.