COVID-19 severity and outcome in multiple sclerosis: Results of a national, registry-based, matched cohort study

Abstract

Background: Risk factors associated with coronavirus disease 2019 (COVID-19) severity in patients with multiple sclerosis (MS) have been described. Recent improvements in supportive care measures and increased testing capacity may modify the risk of severe COVID-19 outcome in MS patients. This retrospective study evaluates the severity and outcome of COVID-19 in MS and characterizes temporal trends over the course of the pandemic in the United States.

Methods: We conducted a comparative cohort study using de-identified electronic health record (EHR) claims-based data. MS patients diagnosed with COVID-19 between February 2, 2020 and October 13, 2020 were matched (1:2) to a control group using propensity score analysis. The primary outcome was a composite of intensive care unit (ICU) admission, mechanical ventilation, and/or death.

Results: A total of 2,529 patients (843 MS and 1,686 matched controls) were included. Non-ambulatory and pre-existing comorbidities were independent risk factors for COVID-19 severity. The risk for the severe composite outcome was lower in the late cohorts compared with the early cohorts.

Conclusions: The majority of MS patients actively treated with a disease-modifying therapy (DMT) had mild disease. The observed trend toward a reduction in severity risk in recent months suggests an improvement in COVID-19 outcome.

Keywords: COVID-19; Disease-modifying therapy; Multiple sclerosis; Outcome; SARS-CoV-2.

Graphical abstract

Fig. 1

Flow diagram of patient selection from the OPTUM® Health Data and Analytics dataset. Abbreviations: COVID-19, coronavirus disease 2019; N, number; PCR, polymerase chain reaction. ^a Two patients with multiple sclerosis were excluded due to missing gender data.

Fig. 2

Demographic characteristics of study patients. The general distribution of by United States division (as defined by the U.S. Census Bureau [1A]) and age at coronavirus disease 2019 (COVID-19) diagnosis (1B) are illustrated.

Fig. 3

Risk for severe COVID-19 outcome (defined as intensive care unit admission, mechanical ventilation, and/or death) expressed as the odds ratio (OR) with 95% confidence intervals (CI). Abbreviations: COVID-19, coronavirus disease 2019; MS, multiple sclerosis.

Fig. 4

Distribution of COVID-19 severity cases (mild [no hospitalization], moderate [hospitalized], and severe [intensive care unit admission, mechanical ventilation, and/or death]) by disease-modifying treatment in patients with multiple sclerosis. Abbreviations: COVID-19, coronavirus disease 2019; S1P, sphingosine-1-phosphate. ^a Dimethyl fumarate, diroximel fumarate, monomethyl fumarate. ^b Fingolimod, siponimod, ozanimod.