Factors and Outcomes Associated with National Institutes of Health Stroke Scale Scores in Acute Ischemic Stroke Patients Undergoing Thrombectomy in United States.

Abstract

Background and purpose: The National Institutes of Health Stroke Scale (NIHSS) is the standard for assessing neurological deficits in acute ischemic stroke patients undergoing thrombectomy. However, data on NIHSS scores in patients undergoing thrombectomy at national-level studies in the United States are lacking.

Methods: Acute ischemic stroke patients admitted between 2018 and 2021 were identified using ICD-10-CM codes from the Nationwide In-patient Sample, with NIHSS scores categorized into specific strata (0-9, 10-19, 20-29, 30-42). We analyzed the effect of NIHSS scores on in-hospital mortality, routine discharge without palliative care (based on discharge disposition), poor outcome defined by NIS SAH outcome measure, and length and costs of hospitalization after adjusting for potential confounders.

Results: The NIHSS score strata among 108,990 acute ischemic stroke patients undergoing thrombectomy were: NIHSS score 0-9 (29.6%), 10-19 (40.6%), 20-29 (26.4%), and 30-42 (3.4%). Patients in the Midwest and West regions (adjusted odds ratio [adjusted OR] = 1.51, p=0.002 and adjusted OR = 1.63, p<0.001, respectively), those treated in rural hospitals (adjusted OR = 1.35, p=0.009) and those who were self-pay (adjusted OR = 1.51, p=0.048) had higher odds of being in higher NIHSS score strata. Patients in higher NIHSS score strata (NIHSS score 10-19, 20-29, and 30-42 had significantly lower odds of discharge home without palliative care (adjusted OR= 0.50, 0.32, and 0.22 respectively, all p<0.001) and higher odds of in-hospital mortality (adjusted OR = 1.51, 2.30, and 3.80 respectively, all p<0.001) compared to those in NIHSS score strata of 0-9. Patients in higher NIHSS score strata had significantly higher hospital stays and higher hospitalization costs.

Conclusions: We provide a comprehensive national-level analysis of NIHSS scores in acute ischemic stroke patients undergoing thrombectomy which may assist in understanding variations in outcomes and resource utilizations in United States.