Objective:

To examine the prevalence, predictors, and outcomes associated with SUD in hospitalized MS patients using a nationally representative sample.

Background:

Recreation Substance use  is prevalent among multiple sclerosis patients but its impact on hospitalization during exacerbation of Multiple sclerosis episodes remains poorly defined on a national scale.

Design/Methods:

A retrospective, cross-sectional analysis of the National Inpatient Sample from 2016-2022 was conducted to identify all adult hospitalizations with a principal or secondary diagnosis of MS. SUD was identified using ICD-10-CM codes. Survey-weighted multivariable logistic, gamma, and multinomial regression models were used to adjust for patient, hospital characteristics and outcomes.

Results:

<p break-words"="">Among 1,054,115 weighted MS hospitalizations (2016–2022), SUD prevalence was 9.3%, driven primarily by alcohol (2.6%), opioids (2.6%), and cannabis (2.6%); opioid poisoning affected 14.1% of the SUD cohort. Patients with SUD were younger (mean 51.4 vs. 57.8 years) and more likely male (aOR: 1.41), with Medicaid insurance (aOR: 1.62), Black race (aOR: 0.64), Hispanic ethnicity (aOR: 0.57), and low-income ZIP codes (aOR: 0.76). Age inversely predicted SUD (aOR for 80+ vs. 18–49: 0.14). After multivariable adjustment, SUD showed no association with in-hospital mortality (aOR: 0.92, 95%CI: 0.80–1.04), though a significant year interaction (p=0.023) revealed lower mortality during 2018–2020 (aOR: 0.65–0.78) and null effects post-2021. SUD independently predicted 10% longer length of stay (6.06 vs. 5.52 days; aGMR: 1.10, 95%CI: 1.08–1.12) but no significant increase in total charges ($60,434 vs. $59,169; p=0.071). Discharge disposition differed markedly: SUD patients had 174% higher risk of leaving against medical advice (3.0% vs. 1.0%; aRRR: 2.74, 95%CI: 2.50–3.00) and reduced likelihood of discharge to skilled nursing facilities (aRRR: 0.72, 95%CI: 0.69–0.76) or with home health care (aRRR: 0.74, 95%CI: 0.71–0.78).

Conclusions:

Despite comparable mortality, SUD among MS patients prolongs hospitalization and dramatically increases against-medical-advice discharges, underscoring urgent needs for integrated addiction services and discharge psychosocial support.