# Racial and Ethnic Disparities in Clinical Characteristics and Outcomes in Adults With Encephalitis: A Retrospective Study

## TL;DR

This study finds that ethnic minority patients with encephalitis tend to be younger, have more severe symptoms, and experience worse outcomes compared to White patients.

## Contribution

The study is the first comprehensive analysis of racial and ethnic disparities in clinical characteristics and outcomes for all causes of adult encephalitis.

## Key findings

- Ethnic minority patients presented younger, had more co-existing HIV, and showed more severe organ dysfunction and abnormal diagnostic findings.
- Ethnic minority patients had worse outcomes on the Glasgow Outcome Scale compared to White patients.
- Abnormal MRI and lower Glasgow Coma Scale scores independently predicted worse clinical outcomes.

## Abstract

This study aims to assess whether adult patients with encephalitis from different racial and ethnic backgrounds exhibit significant differences in clinical presentation, diagnostic findings, and outcomes.

A retrospective cohort study was conducted by utilizing the electronic health records of encephalitis patients in the greater Houston and Baltimore areas. Patients were categorized by race/ethnicity into White or ethnic minority (including Black, Hispanic, and Asian patients). Data was analyzed for the presence of significant differences in clinical characteristics between the two groups.

Among 599 patients, 312 (52.1%) were White and 287 (47.9%) were of an ethnic minority. White patients were more often over sixty years-old upon presentation (43.1% vs 23.9%, P < 0.001) and more likely to present with memory deficits (36% vs 26.3%, P = 0.012). Ethnic minority patients more frequently presented with co-existing HIV (20.3% vs 3.4%, P < 0.001), severe organ dysfunction (44% vs 34.4%, P = 0.028), cerebrospinal fluid (CSF) pleocytosis (white blood cell count ≥5 cells/µL) (83.1% vs 69.3%, P < 0.001), and abnormal electroencephalogram (EEG) findings (84.3% vs 71.9%, P = 0.035). Ethnic minority patients also had worse outcomes on the Glasgow Outcome Scale (GOS) as defined by GOS <4 (59.3% vs 47.2%, P = 0.005). Binary logistic regression identified abnormal magnetic resonance imaging (MRI) and Glasgow Coma Scale (GCS) <13 as independent predictors of an adverse clinical outcome (GOS <4) with an adjusted odds ratio [95% confidence interval] (P value) of 1.609 [1.042-2.486] (P = 0.032) and 2.689 [1.675-4.317] (P < .001), respectively.

Ethnic minority patients with encephalitis present at a younger age and are more likely to have co-existing HIV, severe initial organ dysfunction, CSF pleocytosis, abnormal EEG findings, and worse clinical outcomes. Abnormal MRI and GCS <13 are independent predictors of an unfavorable clinical outcome and may aid in risk stratification.

Race and ethnicity have been shown to affect patient symptoms and outcomes in various diseases, including autoimmune neurological diseases. There has not yet been a comprehensive study on how race and ethnicity affects all causes of encephalitis in adults, including both infectious and autoimmune sources. Our research team used patient records from the past and from two major cities to collect data on patient demographics, symptoms, diagnostic and imaging findings, treatment received while hospitalized, and outcomes/recovery. Patients were categorized by race/ethnicity into two groups for this initial study; White or ethnic minority (including Black, Hispanic, and Asian patients). We analyzed the data to see if there were major differences in any factors between the two groups. The total number of patients was 599, with 52.1% being White and 47.9% of an ethnic minority. We found that White patients tended to present at a much older age and with memory gaps. Ethnic minority patients were sicker when they presented to the hospital in terms of other diseases they co-presented with, as well as initial imaging and lab findings. Our ethnic minority patients had worse outcomes in terms of neurological recovery and functional status by their discharge. A separate analysis showed that abnormal magnetic resonance imaging (MRI) results and a certain level of consciousness upon admission were indicative of worse outcomes by discharge. Our study revealed that ethnic minority patients with encephalitis are more likely to present younger and with more severe illness upon hospitalization, which may be a potential reason for worse functional outcomes. More work needs to be done to differentiate symptoms and outcomes between the two groups based on the cause of encephalitis (infectious vs. autoimmune). This study has also identified abnormal MRI and level of consciousness upon admission as potential predictors of worse outcomes, which should be further studied.