Abstract
OBJECTIVES: Stroke severity is an important prognostic indicator of morbidity and mortality, but often not recorded outside of specialised stroke centres. We aimed to develop a scoring rule and validate standardised assessment of the National Institutes of Health Stroke Scale (NIHSS) from medical records.
METHODS: We developed a standardised assessment of the NIHSS from medical records. Four trained raters independently assessed the charts of 100 patients with first-ever stroke, randomly selected from the population-based Rotterdam Study cohort. Interrater agreement was determined using the intraclass correlation coefficient (ICC), and Fleiss' kappa for major versus minor stroke. We validated the scoring method against 29 prospective, clinical NIHSS ratings, using Kendall's tau and Cohen's kappa.
RESULTS: Of 100 included patients with stroke (mean age 80 years, 62% women), 71 (71%) were admitted to hospital and 9 (9%) were seen in outpatient clinic, whereas 20 (20%) were treated exclusively by their general practitioner or nursing home physician. Interrater agreement for retrospective, chart-based NIHSS ratings was excellent when assessed continuously (ICC: 0.90), and for minor versus major stroke (for NIHSS>3: κ=0.79, NIHSS>5: κ=0.78). Interrater agreement was good both for hospital-based and out-of-hospital settings (ICC: 0.97 and 0.75 respectively). Overall, assessment from medical records was in excellent agreement with prospective NIHSS ratings (τ=0.83; NIHSS>3: κ=0.93, and NIHSS>5: κ=0.93). However, for severe stroke (NIHSS>10) retrospective assessment tended to underestimate severity by 1-3 points on the NIHSS, which was accompanied by a somewhat lower interrater agreement for those more severe cases (NIHSS>10: κ=0.62).
CONCLUSIONS: Assessment of stroke severity according to the NIHSS on the basis of medical records is feasible and reliable in population-based cohorts of patients with stroke. These findings facilitate more individualised risk estimates in observational studies that lack prospective ascertainment of stroke severity.
| Original language | English |
|---|---|
| Article number | 106992 |
| Pages (from-to) | 106992 |
| Journal | Journal of Stroke and Cerebrovascular Diseases |
| Volume | 32 |
| Issue number | 4 |
| Early online date | 17 Feb 2023 |
| DOIs | |
| Publication status | Published - Apr 2023 |
Bibliographical note
Funding Information:The Rotterdam Study is supported by the Erasmus MC and Erasmus University Rotterdam, The Netherlands Organisation for Scientific Research (NWO), The Netherlands Organisation for Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (RIDE), the Netherlands Genomics Initiative, the Ministry of Education, Culture and Science, the Ministry of Health, Welfare and Sports, the European Commission (DG XII), and the Municipality of Rotterdam. This study is further funded by the European Union's Horizon 2020 research and innovation programme as part of the Common mechanisms and pathways in Stroke and Alzheimer's disease (CoSTREAM) project ( www.costream.eu , grant agreement no. 667375). Additionally, BPB and MKI were supported by the Erasmus Medical Centre MRACE grant (grant number 386070).
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© 2023 The Author(s)