To determine the associations between neighborhood-level indices and clinical outcomes in pNMDARE.

Epidemiologic studies show that pNMDARE has a higher incidence in non-White populations. However, further characterization of health disparity risk factors impacting disease outcomes are unknown.

We conducted a multi-center retrospective cohort study of pNMDARE from 2007-2022 at 5 geographically diverse tertiary children’s hospitals. Neighborhood-level indices included Area Deprivation Index (ADI) national percentiles (1-100) and state deciles (1-10), and Childhood Opportunity Index (COI) normed scores (1-100) and quintiles (1-20 “Very Low”; 21-40 “Low”; 41-50 “Moderate”; 51-80 “High”; 81-100 “Very High”) and domains (ºÃÉ«ÏÈÉú [ED], Health and Environment [HE]), Socioeconomic [SE]). Outcomes included hospitalization duration, EEG and MRI abnormalities, ICU admission, immunotherapy, and modified Rankin Scores (mRS) at admission and 1 year. We employed univariate Wilcoxon ranked sum test to compare disadvantaged (1-40) vs. non-disadvantaged (41-100) COI groups and multivariable linear regression modeling adjusting for age of onset and sex to determine associations between ADI/COI and clinical outcomes.

We included 200 participants (median age of onset 12.6 years, IQR 5.9 – 15.0, 64% female) in the analysis; 43.5% identified as White Hispanic, 14.5% White Non-Hispanic, 42% Non-White. Median composite national COI score was low (33.0, IQR 12.5-67.0): 57% composite, 52% ED, 68% HE and 54% SE domains were in “Very Low” or “Low” quintiles. mRS at admission was significantly different between disadvantaged vs non-disadvantaged groups for composite COI (p=0.04) and COI HE (p=0.009). Higher deprivation (high ADI, p=0.005, low COI, p=0.004) was associated with higher mRS at admission but not 1 year mRS. There were no associations between ADI/COI and other clinical variables.

A high proportion of pNMDARE patients are Non-White or Hispanic aligning with prior data. More than half come from disadvantaged neighborhoods based on COI with higher mRS at presentation suggesting a disparity in disease expression.