Research Article: Co-recorded conditions in ischemic and hemorrhagic stroke: a 20-year national analysis of 598,186 natural deaths with machine learning
Abstract:
The purpose of this study was to characterize the co-occurrence patterns of co-recorded conditions in ischemic and hemorrhagic stroke and identify co-recorded conditions using a large national dataset of fatal, subtype-confirmed stroke cases from Brazil. We analyzed 598,186 natural deaths recorded in the Brazilian Mortality Information System (SIM) between 2000 and 2019, comprising 288,724 (48.3%) hemorrhagic and 309,462 (51.7%) ischemic stroke. Hierarchical clustering was performed to identify co-recorded condition clusters, while association rule mining using the Apriori algorithm uncovered hidden patterns of disease co-occurrence. Logistic regression, random forest, and XGBoost models were developed to classify stroke subtype based on demographic characteristics and co-recorded condition profiles. Ischemic stroke patients had significantly higher co-recorded condition burden (median 2, IQR 1–3) compared to hemorrhagic stroke (median 1, IQR 1–2; p <?0.001). For hemorrhagic stroke, 12 association rules were identified; the strongest involved co-occurrence of infectious and respiratory diseases (e.g., {hypertension?=?Yes, infectious_disease?=?Yes}???{respiratory_disease?=?Yes}, lift?=?2.57) and of endocrine/metabolic conditions with hypertension (lift?=?1.67), whereas the rule {mental_disorders?=?Yes}???{hypertension?=?Yes} (lift?=?1.27, confidence?=?53.9%) was the weakest of the 12 rules. In contrast, ischemic stroke yielded 8 rules reflecting associations among infectious, respiratory, genitourinary, and endocrine/metabolic conditions. The logistic regression model achieved an AUC of 0.768 for predicting stroke subtype, with consistent performance across sensitivity analyses. Age-standardized analyses showed that ischemic stroke proportion increased from 48.8 to 51.5% over 20?years, with approximately half of the crude increase attributable to population aging (crude ischemic proportion reached 54.7%). Co-recorded condition burden increased substantially in both subtypes (?3 co-recorded conditions in ischemic stroke: 24.8–33.3%). We observed that hemorrhagic and ischemic stroke have different co-occurrence patterns of co-recorded conditions: hemorrhagic stroke exhibited simpler co-occurrence patterns centered on hypertension together with infectious, respiratory, and endocrine/metabolic conditions, while ischemic stroke was characterized by clustered cardiovascular and metabolic multimorbidity. These findings warrant further investigation in prospective studies.
Introduction:
Stroke remains a leading cause of mortality and long-term disability worldwide, with an estimated 12.2 million incident cases and 6.6 million deaths annually ( 1 ). The global burden of stroke has increased by 70% over the past three decades, driven largely by demographic transitions and the rising prevalence of cardiometabolic risk factors in low- and middle-income countries (LMICs) ( 2 , 3 ). While ischemic stroke accounts for approximately 70% of all strokes globally, the proportion of hemorrhagic stroke…
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