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Stroke Awareness Month Focus: National Institutes of Health Stroke Scale

Published on 

Wednesday, May 26, 2021

 | Coding 
 | Quality 

MMP and RealTime Medicare Data (RTMD) have collaborated to highlight Health Awareness Month topics throughout the year with an infographic spotlight on Medicare Fee-for-Service (FFS) paid claims data comparatives and a related article. May is Stroke Awareness Month. The American Heart Association notes this month was created to promote public awareness and reduce the incidence of stroke in the United States. This article focuses on the National Institutes of Health Stroke Scale (NIHSS).

Did You Know?

Originally, the National Institutes of Health Stroke Scale (NIHHS) was developed to measure baseline data for patients involved in acute stroke clinical trials. In 1995, after the publication of the Trial, the NIHSS became the de facto standard for rating clinical deficits in stroke trials.*

Prior to the implementation of ICD-10-CM, there was no way for Coding Professionals to capture the NIHSS. In fact, it wasn’t until FY 2017 that coding guidance was added to the ICD-10-CM Official Guidelines for Coding and Reporting related to coding NIHSS codes (link).

Why Does this Matter?

In the FY 2018 IPPS Final Rule, CMS finalized a refinement to the Stroke 30-Day Mortality Measure (MORT-30-STK) for the FY 2023 payment determination by including the NIHSS. CMS noted in Final Rule that they had “received comments that the more rigorous risk adjustment facilitated by the NIH Stroke Scale would help ensure the measure accurately risk adjusts for different hospital populations without unfairly penalizing high-performance providers, and the NIH Stroke Scale is well validated, highly reliable, widely used by providers caring for stroke patients, and a strong predictor of mortality and short- and long-term functional outcomes. However, we were not able to test the ICD-10 CM codes for NIH Stroke Scale score in claims during measure development because those codes were not available for hospitals to use in their claims until October 2016. Therefore, we proposed this measure now to inform hospitals they should begin to include the NIH stroke severity scale codes in the claims they submit for patients with a discharge diagnosis of ischemic stroke.”

This month’s related RTMD infographic spotlights how often one of the NIHSS codes was included on Ischemic Stroke MS-DRGs 061, 062, and 063 Medicare FFS paid claims in FY 2019. Across RTMD’s Footprint, 40.1% of the claims included an NIHSS. Drilling down to the state compare, you will find a wide variance in how often the NIHSS codes are being captured.

The February 1, 2021 Update to the MORT-30-STK Measure notes that “the major revision is to include the NIH Stroke Scale as a measure of stroke severity in the risk-adjustment.”

What You Can Do About It?

Be aware that the absence of an NIHSS on your acute stroke claims can negatively impact the risk adjustment for your Hospital 30-Day Mortality Following Acute Ischemic Stroke Hospitalization Measure.

Then moving forward:

  • Make sure this information is consistently being documented in your medical records, and
  • Educate your Coding staff about the NIHSS and the need to ensure it is coded on all of your acute stroke cases.
Education Resource

The National Institutes of Health (NIHs) website Know Stroke (link) includes health professional specific resources related to NIHSS.

*”Using the National Institutes of Health Stroke Scale A Cautionary Tale.” Lyden, Patrick. AHA Stroke Journal, 11 Jan 2017,

Article Author: Beth Cobb, RN, BSN, ACM, CCDS
Beth Cobb, RN, BSN, ACM, CCDS, is the Manager of Clinical Analytics at Medical Management Plus, Inc. Beth has over twenty-five years of experience in healthcare including eleven years in Case Management at a large multi-facility health system. In her current position, Beth is a principle writer for MMP’s Wednesday@One weekly e-newsletter, an active member of our HIPAA Compliance Committee, MMP’s Education Department Program Director and co-developer of MMP’s proprietary Compliance Protection Assessment Tool.

This material was compiled to share information.  MMP, Inc. is not offering legal advice. Every reasonable effort has been taken to ensure the information is accurate and useful.