To identify the reasons and risk factors for emergency department (ED) visits among multiple sclerosis (MS) patients.

Many MS patients experience comorbidities and social determinants of health, making access to emergency services a critical aspect of MS care. While advancements in disease modifying therapies (DMTs) have improved MS outcomes, the uptake of DMTs varies among people living with MS.

A retrospective nested case-control study was conducted at Massachusetts General Hospital, analyzing 900 MS patients (300 cases with ED visits and 600 MS controls without ED visits),  June 2019-December 2023. Data on demographics, DMT efficacy, comorbidities, and insurance type were analyzed. A Charlson Comorbidity Index (CCI) was constructed and modified using current International Classification of Diseases. Odds ratios (ORs) were calculated from age-adjusted multivariable models to assess the risk of specific factors with ED visits in MS.

Of 1,462 evaluated MS patient charts, 900 were randomly selected. The sample was predominantly female (70.7% cases, 74.7% controls) and White (79.0% cases, 87.2% controls). Cases had a higher mean CCI score (0.83) than controls (0.05). DMT utilization by efficacy in cases vs controls was: none (64.3% vs 39.5%), high (23.3% vs 32.5%), low (8.3% vs 16.0%), and medium (4.0% vs 12.0%). ED utilization analysis showed that 51.8% of MS patients had a single ED visit. Risk factors for going to the ED in MS patients were: higher CCI (OR=4.23, p<0.001), absence of DMT (OR=2.56, p<0.001), being Non-White (OR=0.48, p=0.006) and having public or no insurance (OR=1.99, p<0.001). Ethnicity and gender were each not independently statistically significant.

Specific risk factors for ED use in MS patients were identified in this large academic urban center, highlighting the need for comprehensive management of comorbidities. The high number of MS patients who present to the ED not taking DMTs presents an opportunity to improve MS care.