Neurology
October 16, 2026 · via Europe PMC
Incidence and Post-Stroke Survival in the Normandy Stroke Population-Based Study (2017-2022): Impact of Time-Based Versus Tissue-Based Definitions.
Nehme A, Schneckenburger R, Watrin M, +10 more, Touzé E.
AI summary — for doctors, generated from the abstract only
Moving from a time-based to a tissue-based stroke definition modestly increased measured stroke incidence and survival, with larger effects at younger ages; part of the abstract's methods is cut off.
What was studied
Population-based Normandy Stroke Study (Caen, France; 2017-2022) comparing time-based (symptoms at least 24 hours) with ICD-11 tissue-based definitions on incidence and post-stroke survival among 3,826 first-ever strokes meeting the tissue-based definition.
Key findings
- Age-standardized incidence was 161 (95% CI 156-166) per 100,000 person-years, and 3-year mortality was 36.4% (95% CI 34.9-38.0)
- The tissue-based definition increased incidence by 6.5% and reduced 3-year mortality by 3.9% compared with the time-based definition
- The incidence increase was larger in people under 55 (all strokes +8.5% vs +6.0%; ischemic +12.5% vs +7.3%)
Clinical relevance
Registries and health planners should be aware that ICD-11 adoption will shift incidence and outcome statistics, especially in younger adults, complicating trend comparisons.
Who should care
Limitations
Single French region, and the definition text in the Methods is truncated in the abstract. Findings reflect classification effects on statistics, not changes in patient care.
A tissue-based stroke definition modestly raises incidence and lowers measured mortality, so consistent definitions matter for surveillance.
This is an AI-generated summary of the published abstract, not a clinical recommendation. It may not reflect the full text or subsequent updates — verify against the original source before acting on it.
Abstract
Objectives
The 11th edition of the International Classification of Diseases (ICD-11) incorporates a tissue-based definition of stroke and may alter estimates of incidence and outcomes. We assessed whether transitioning from a time-based to a tissue-based definition introduces age-dependent changes in stroke incidence and post-stroke survival.
Methods
The Normandy Stroke Study is a population-based study using multiple overlapping sources to identify stroke cases in Caen-Normandy-Metropole, France. Events occurring between May 15, 2017, and December 31, 2022, were classified using time-based (symptoms ≥24 hours) and tissue-based definitions (symptoms ≥24 hours or <24 hours with neuroimaging evidence of ischemic injury).
Results
Among 3,826 first-ever strokes meeting the tissue-based definition, median (IQR) age was 76 (64-85) years, and 1,932 (50.5%) were female. The age-standardized incidence rate of stroke (95% CI) was 161 (156-166) per 100,000 person-years (ESP2013), including 132 (128-137) for ischemic or undetermined stroke, 22 (20-24) for intracerebral hemorrhage, and 7 (6-8) for subarachnoid hemorrhage. Three-year mortality was 36.4% (95% CI 34.9-38.0). Compared with the time-based definition, the tissue-based definition increased stroke incidence by 6.5% and reduced 3-year mortality by 3.9%. The impact of the tissue-based definition on stroke incidence was greater at younger ages (all strokes: younger than 55 years = +8.5%; 55 years or older = +6.0%; ischemic stroke: younger than 55 years = +12.5%; 55 years or older = +7.3%).
Discussion
Adoption of a tissue-based definition modestly increased stroke incidence and post-stroke survival, with greater impacts at younger ages. Implementation of ICD-11 may introduce age-related differences in temporal trends, highlighting the importance of consistent definitions in stroke surveillance.
DOI
10.1212/wnl.0000000000218457
PMID
42886872
Research metadata (titles, abstracts, authors, publication dates) is sourced from Europe PMC, which aggregates content from PubMed/MEDLINE, PubMed Central, and other providers under the U.S. National Library of Medicine (NLM/NCBI). NLM does not claim copyright on abstracts; the original journal publishers or authors may hold rights to the full articles. AI-generated summaries are derived only from the abstract, never the full text, and are always labeled as AI-generated.
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