Development and validation of risk score to estimate 1-year late poststroke epilepsy risk in ischemic stroke patients

Abstract

Nai-Fang Chi,1,2 Yi-Chun Kuan,1–3 Yao-Hsien Huang,1,2 Lung Chan,1,2 Chaur-Jong Hu,1,2,4 Hung-Yi Liu,5 Hung-Yi Chiou,6 Li-Nien Chien7 1Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, Republic of China; 2Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan, Republic of China; 3Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China; 4PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan, Republic of China; 5Health and Clinical Research Data Center, College of Public Health, Taipei Medical University, Taipei, Taiwan, Republic of China; 6School of Public Health, College of Public Health, Taipei Medical University, Taipei, Taiwan, Republic of China; 7School of Health Care Administration, College of Management, Taipei Medical University, Taipei, Taiwan, Republic of China Objective: This study aimed to develop and validate a prognostic model for the 1-year risk of late poststroke epilepsy (PSE). Materials and methods: We included patients initially diagnosed with ischemic stroke between 2003 and 2014 in a National Health Insurance claims-based cohort in Taiwan. Patients were further divided into development and validation cohorts based on their year of stroke diagnosis. Multivariable Cox regression with backward elimination was used to analyze the association between 1-year PSE and risk factors before and on stroke admission. Results: In total, 1,684 (1.93%) and 725 (1.87%) ischemic stroke patients comprising the development and validation cohorts, respectively, experienced late PSE within 1 year after stroke. Seven clinical variables were examined to be independently associated with 1-year risk of PSE. We developed a risk score called “PSEiCARe” ranging from 0 to 16 points, comprising the following factors: prolonged hospital stay (>2 weeks, 1 point), seizure on admission (6 points), elderly patients (age ≥80 years, 1 point), intensive care unit stay on admission (3 points), cognitive impairment (dementia, 2 points), atrial fibrillation (2 points), and respiratory tract infection (pneumonia) on admission (1 point). Patients were further classified into low-, medium-, high-, and very-high-risk groups. The incidence (per 100 person-years) was 0.64 (95% CI: 0.56–0.71) for the low-risk, 2.62 (95% CI: 2.43–2.82) for the medium-risk, 10.3 (95% CI: 9.48–11.3) for the high-risk, and 28.2 (95% CI: 24.0–33.0) for the very-high-risk groups. Discrimination and calibration were satisfactory, with a Harrell’s C of 0.762 in the development model and 0.792 in the validation model. Conclusion: PSEiCARe is an easy-to-use prognostic score that integrates patient characteristics and clinical factors on stroke admission to predict 1-year PSE risk; it has the potential to assist individualized patient management and improve clinical practice, thereby preventing the occurrence of late PSE. Keywords: poststroke epilepsy, prediction model, risk score, population-based, claim analysis

Keywords

• poststroke epilepsy
• prediction model
• risk score
• population-based
• claim analysis