Validity of stroke severity assessment using medical records in a population-based cohort.

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.

Dementia Risk Following Ischemic Stroke: A Systematic Review and Meta-Analysis of Factors Collected at Time of Stroke Diagnosis.

BACKGROUND: The majority of stroke cases are ischemic in origin and ischemic stroke survivors represent a high-risk population for progression to dementia. OBJECTIVE: To determine incidence rates and predictors of dementia after ischemic stroke. METHODS: A systematic review and meta-analysis compliant with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). RESULTS: 5,843 studies were screened for title and abstract. 292 eligible studies were screened for full text. A total of 22 studies met the inclusion criteria and were included, representing 55,929 ischemic stroke survivors. Cumulative incidence of dementia after stroke was 20% at 5 years, 30% at 15 years, and 48% at 25 years of follow-up. Dementia incidence rates were 1.5 times higher among patients with recurrent ischemic stroke compared to patients with first-time stroke. Predictors of dementia after ischemic stroke included female gender (OR 1.2, 95% CI (1.1, 1.4)), hypertension (1.4, (1.1, 2.0)), diabetes mellitus (1.6, (1.3, 2.1)), atrial fibrillation (1.9, (1.2, 3.0)), previous stroke (2.0, (1.6, 2.6)), presence of stroke lesion in dominant hemisphere (2.4, (1.3, 4.5)), brain stem or cerebellum (OR 0.5, (0.3, 0.9)) or frontal lobe (3.7, (1.2, 12.0)), presence of aphasia (OR 7.9, (2.4, 26.0)), dysphasia (5.8, (3.0, 11.3)), gait impairment (1.7, (1.1, 2.7)), presence of white matter hyperintensities (3.2, (2.0, 5.3)), and medial temporal lobe atrophy (3.9, (1.9, 8.3)). CONCLUSION: Factors routinely collected for stroke patients are a useful resource for monitoring dementia progression in this population. In the present meta-analysis, cardiovascular factors, stroke location, stroke-related disability and chronic brain changes were predictors of dementia after ischemic stroke.