Stroke Measures Analysis of pRognostic Testing – Mortality (SMART-M) nomogram predicts long-term mortality after ischaemic stroke

Background: Predicting long-term mortality is essential for understanding prognosis and guiding treatment decisions in patients with ischemic stroke. Therefore, this study aimed to develop and validate the method for predicting 1-year and 5-year mortality after ischemic stroke. Methods: We utilized data from the linked dataset comprising the administrative claims database of the Health Insurance Review and Assessment Service and the Clinical Research Center for Stroke registry data for patients with acute stroke within 7 days of onset. The outcome was all-cause mortality following ischemic stroke. Clinical variables linked to long-term mortality following ischemic stroke were determined. A nomogram was constructed based on the Cox’s regression analysis. The performance of the risk prediction model was evaluated using the Harrell's C index. Results: This study included 42,207 ischemic stroke patients, with a mean age of 66.6 years and 59.2% being male. The patients were randomly divided into training (n=29,916) and validation (n=12,291) groups. Variables correlated with long-term mortality in patients with ischemic stroke, including age, sex, body mass index, stroke severity, stroke mechanisms, onset-to-door time, pre-stroke dependency, history of stroke, diabetes mellitus, hypertension, coronary artery disease, chronic kidney disease, cancer, smoking, fasting glucose level, previous statin therapy, thrombolytic therapy such as intravenous thrombolysis and endovascular recanalization therapy, medications, and discharge modified Rankiin Scale were identified as predictors. We developed a predictive system named Stroke Measures Analysis of pRognostic Testing – Mortality (SMART-M) by constructing a nomogram using the identified features. The C-statistics of the nomogram in the developing and validation groups were 0.806 (95% confidence interval [CI], 0.802–0.812) and 0.803 (95% CI, 0.795–0.811), respectively. Conclusions: The SMART-M method demonstrated good performance in predicting long-term mortality in ischemic stroke patients. This method may help physicians and family members understand the long-term outcomes and guide the appropriate decision-making process.