Multiple sclerosis is not associated with an increased risk for severe COVID-19: a nationwide retrospective cross-sectional study from Germany

BACKGROUND: Since the coronavirus disease 2019 (COVID-19) has risen, several risk factors have been identified, predicting a worse outcome. It has been speculated that patients with Multiple sclerosis (MS) have an increased risk for a severe course of COVID-19 due to a suspected higher vulnerability. Therefore, we aimed to analyze the impact of comorbid MS on the outcome of patients with COVID-19 in Germany. METHODS: We conducted a retrospective cross-sectional study using the administrative database of all hospitalized patients diagnosed with PCR-confirmed COVID-19 (n = 157,524) in Germany during 2020. The cohort was stratified according to the presence (n = 551) or absence (n = 156,973) of comorbid MS, including discrimination of MS subtypes. Primary outcome measures were admission to the intensive care unit (ICU), use of invasive or non-invasive ventilation, and in-hospital mortality. Differences were investigated using rates and odds ratios as estimates. Pooled overall estimates, sex-stratified estimates, age-group stratified estimates, and MS subtype stratified estimates were calculated for all outcomes under the random-effects model. RESULTS: Among 157,524 patients hospitalized with COVID-19, 551 had a concurrent MS diagnosis (0.3%). Overall, univariate analysis showed lower rates of ICU admission (17.1% versus 22.7%, p < 0.001), lower use of ventilation (9.8% versus 14.5%, p < 0.001) and lower in-hospital mortality (11.1% versus 19.3%, p < 0.001) among COVID-19 patients with comorbid MS. This finding was stable across the subgroup analysis of sex and MS subtype but was attenuated by age-stratification, confirming equal odds of in-hospital mortality between COVID-19 patients with and without MS (log OR: 0.09 [95% CI: − 0.40, 0.59]). CONCLUSIONS: Although there might be differences in risk within the MS patients’ population, this large-scale nationwide analysis found no evidence for a worse outcome of COVID-19 in patients with comorbid MS compared to non-MS individuals. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s42466-021-00143-y.