Validation of a neurovascular comorbidity index for risk adjustment of comorbid conditions among ischemic stroke patients receiving reperfusion treatment

Abstract

Objective: To validate a comorbidity index specific to neurovascular patients and determine its performance relative to the Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI) among ischemic stroke patients receiving reperfusion treatments.

Methods: Patients with ischemic stroke were identified in the National Inpatient Sample from Quarter 4 2015 to Quarter 4 2017. Ischemic stroke patients receiving reperfusion treatment, either with intravenous thrombolysis (IVT) only or mechanical thrombectomy (MT), were studied. The accuracy of the neurovascular comorbidities index (NCI) was compared to both the CCI and ECI in predicting in-hospital death and poor outcome (defined as death prior to discharge or discharge to a short-term hospital, a skilled nursing facility, an intermediate care facility, another long-term facility, or home health care).

Results: There were 25,147 ischemic stroke patients who received reperfusion therapy with either IVT only or MT (with or without IVT). Approximately 6.9% of patients died during their hospitalization, and 65.4% of patients were classified as having a poor outcome based on their discharge disposition. The NCI outperformed both the CCI and ECI in predicting in-hospital death (IVT only, p<0.0001; MT, p<0.0001) and poor outcomes (IVT only, p<0.0001; MT, p<0.0001).

Conclusion: The NCI is a more powerful predictor of in-hospital death and poor outcomes when compared to the CCI or ECI among ischemic stroke patients receiving reperfusion therapies. Further validation studies are needed to confirm the accuracy of the NCI among other neurovascular patient populations.

Keywords: Comorbidities; Death; Index; Outcomes; Stroke.