Performance of Charlson and Elixhauser Comorbidity Index to Predict in-Hospital Mortality in Patients with Stroke in Sumadija and Western Serbia

Biljana Bajic; Igor Galic; Natasa Mihailovic; Svetlana Ristic; Svetlana Radevic; Violeta Iric Cupic; Sanja Kocic; Aleksandra Arnaut

doi:10.18502/ijph.v50i5.6114

Performance of Charlson and Elixhauser Comorbidity Index to Predict in-Hospital Mortality in Patients with Stroke in Sumadija and Western Serbia

Iran J Public Health. 2021 May;50(5):970-977. doi: 10.18502/ijph.v50i5.6114.

Authors

Biljana Bajic¹, Igor Galic², Natasa Mihailovic³, Svetlana Ristic⁴, Svetlana Radevic⁵, Violeta Iric Cupic⁶, Sanja Kocic^{3

5}, Aleksandra Arnaut⁷

Affiliations

¹ Health Promotion Center, Institute of Public Health Montenegro, Podgorica, Montenegro.
² Center for Control and Prevention of Noncommunicable Diseases, Institute for Public Health Montenegro, Podgorica, Montenegro.
³ Department of Biostatistics and Informatics, Institute of Public Health Kragujevac, Kragujevac, Serbia.
⁴ Institute for Oncology and Radiology of Serbia, Belgrade, Serbia.
⁵ Department of Social Medicine, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
⁶ Department of Internal Medicine, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
⁷ Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.

Abstract

Background: Comorbidities are major predictors of in-hospital mortality in stroke patients. The Charlson comorbidity index (CCI) and the Elikhauser comorbidity index (ECI) are scoring systems for classifying comorbidities. We aimed to compare the performance of the CCI and ECI to predict in-hospital mortality in stroke patients.

Methods: We included patients hospitalized for stroke in the Clinical Center of Kragujevac, Serbia for the last 7 years. Hospitalizations caused by stroke, were identified by the International Classification of Diseases-10 (ICD-10) codes I60.0 - I69.9. All patients were divided into two cohorts: Alive cohort (n=3297) and Mortality cohort (n=978).

Results: There were significant associations between higher CCIS and increased risk of in-hospital mortality (HR = 1.07, 95% CI = 1.01-1.12) and between higher ECIS and increased risk of in-hospital mortality (HR = 1.04, 95% CI = 0.99-1.09). Almost 2/3 patients (66.9%) had comorbidities included in the CCI score and 1/3 patients (30.2%) had comorbidities included in the ECI score. The statistically significant higher CCI score (t = -3.88, df = 1017.96, P <0.01) and ECI score (t = -6.7, df = 1447.32, P <0.01) was in the mortality cohort.Area Under the Curve for ECI score was 0.606 and for CCI score was 0.549.

Conclusion: Both, the CCI and the ECI can be used as scoring systems for classifying comorbidities in the administrative databases, but the model's ECI Score had a better discriminative performance of in-hospital mortality in the stroke patients than the CCI Score model.

Keywords: Charlson comorbidity index; Elixhauser comorbidity index; In-hospital mortality; Stroke.