Increasing National Burden of Encephalitis, Myelitis, and Encephalomyelitis: Insights from the ICD-10 Era and Implications for Diagnostic Coding
Ka-Ho Wong1, Ava Easton2, Melissa Wright3, Yoji Hoshina4, Sydney Lee3, Tammy Smith5, Adam De Havenon6, Stacey Clardy3
1U of U Neurology Clinic, 2The Encephalitis Society, 3University of Utah, 4University of Utah Health, 5Imaging and Neurosciences Center, 6Yale University
Objective:
To evaluate national trends in hospitalizations for encephalitis, myelitis, and encephalomyelitis in the United States using the National Inpatient Sample (NIS) from 2016 to 2023.
Background:
Encephalitis, myelitis, and encephalomyelitis represent a heterogeneous group of inflammatory disorders of the central nervous system with diverse etiologies and clinical presentations. In the ICD-10 era, the extent to which broad diagnostic codes capture the national burden of these distinct conditions remains limited.
Design/Methods:
We conducted a retrospective cross-sectional study using the Healthcare Cost and Utilization Project NIS from 2016 through 2023. Adult hospitalizations with a principal diagnosis of ICD-10 code “G04*” were identified. Survey-weighted analyses were performed to generate national estimates, accounting for the complex sampling design. Temporal trends in hospitalization volume were assessed.
Results:
A total of 147,970 weighted hospitalizations were identified during the study period. Annual hospitalizations increased from 14,795 (95% CI, 13,444–16,146) in 2016 to 21,585 (95% CI, 20,286–22,884) in 2023, representing an approximate 46% increase. A modest plateau was observed in 2019–2020, which may reflect disruptions in healthcare utilization during the COVID-19 pandemic, followed by continued increases through 2023.
Conclusions:
Hospitalizations for encephalitis, myelitis, and encephalomyelitis have increased substantially in the United States from 2016 to 2023. However, this trend must be interpreted in the context of the clinical and etiologic heterogeneity encompassed within the G04* diagnostic category. The absence of more granular ICD-10 codes for distinct conditions such as autoimmune encephalitis, a well-recognized clinical entity, may contribute to the aggregation of diverse disease processes under a single code. These findings highlight limitations in diagnostic specificity and underscore the need for more refined coding frameworks to better characterize disease subtypes and inform clinical and epidemiologic research.
Generative AI Usage
No, did not use generative AI in the drafting or editing in this abstract.
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