Objective:

Identify disparities in NIHSS documentation in acute ischemic stroke patients.

Background:

The National Institutes of Health Stroke Scale (NIHSS) is used as the standard tool for assessing ischemic stroke severity and determining acute treatments like intravenous thrombolytics or mechanical thrombectomy. However, real-world adoption and documentation patterns at the national level have not been well depicted. Understanding these patterns is critical for identifying potential disparities in the application of standardized assessments. 

Design/Methods:

We used the National Inpatient Sample (2016-2022) and identified adults 18 years or older admitted non-electively with ischemic stroke (I63.x in the primary position). The primary outcome was documentation of an NIHSS score (R29.7x). In addition to reporting the annual proportion with NIHSS documentation, a multivariable logistic regression was used to identify patient and hospital level predictors of NIHSS documentation. 

Results:

Among 721,154 ischemic stroke hospitalizations, NIHSS documentation increased linearly from 4.4% in 2016 to 66.8% in 2022 (p>0.001). In the adjusted models, documentation was less common among older adults(>54 years), Black (OR 0.88), Hispanic (0.91) patients (all p<0.001). Furthermore, documentation was significantly less common for low-income zip codes (0.87) and rural areas (0.83) (all p<0.001). Regionally, patients in the West (0.83, p<0.001) are less likely to receive NIHSS documentation compared to patients in the South and Midwest.  

Conclusions:

Since 2016, NIHSS documentation for acute ischemic stroke has increased significantly. However, it remains less common among adults older than 65, Black and Hispanic patients, low-income zip codes, rural areas, and in the West. For low-income and rural populations, this may reflect limited hospital resources, which could contribute to racial disparities in these settings. Implementing standardized NIHSS documentation protocols across all hospitals is essential for treatment plans and functional outcomes. Targeted resource allocation and increased funding for under-resourced hospitals are also critical to ensuring equitable stroke care.