Patients with multiple sclerosis (MS) had similar factors associated with adverse COVID-19 outcomes vs other populations, but these risks were found to decrease with subsequent COVID-19 waves, investigators found.
Factors associated with poor outcomes from COVID-19 were found to be similar between populations with multiple sclerosis (MS) and other groups, including that disease-modifying therapies (DMTs) are not associated with adverse outcomes, investigators of a study concluded.
The study, published in Multiple Sclerosis and Related Disorders, which sought to clarify the impact of COVID-19 and MS management on patients with MS in the United Kingdom, also found that mortality risks were lower during the second COVID-19 wave that hit the countries.
“Given the rapid evolution of the symptomatology of the virus, it was important to capture a broad spectrum of measures, both about the COVID-19 infection and essential data specific to MS,” wrote the investigators.
Following the onset of the COVID-19 pandemic, the UK experienced 2 lockdown periods. The first occurred from March 23 to August 14, 2020, and the second occurred from November 5 to December 2, 2020. Patients with MS often experience chronic disability and receive immunosuppressive DMTs, which have led experts to have some concerns and uncertainty about the risk of COVID-19 among patients with MS.
In response to the ongoing need to explore the impact of COVID-19 on MS, a platform was added to the UK Multiple Sclerosis Register (UKMSR) to allow clinicians to record data about people with MS who have COVID-19. The online electronic case return form was delivered securely to all MS neurologists in the UK.
The investigators found 292 patients with MS from the UKMSR, of whom 193 had COVID-19 and data available between March 27, 2020, and March 16, 2021, and were included in the analysis. The median age of the 292 patients was 50, and 65.8% were women. Relapsing-remitting MS cases comprised 59.3% (n = 173) of the entire register, and 35.3% (n = 103) had unknown MS type. Also, 34.8% were considered to be mildly disabled, 22.8% were said to be moderately disabled, and 42.4% were considered severely disabled.
Of the 85 patients who experienced hospitalization, 54 were due to COVID-19, 7 for reasons associated with MS, and 4 due to lack of support at home. Hospitalizations lasted for a median of 9 days regardless of survival. The most common symptoms of infection associated with admission were respiratory problems and high temperature (P < .001 for both). Older age, male gender, having a comorbidity, increased disability, and progressive MS were associated with being hospitalized (P < .001). However, patients who were on a DMT were found to have a lower likelihood of being admitted to a hospital (P < .001).
“This is perhaps because those on DMTs are generally younger and have lower levels of disability than those not on DMTs, would be less at risk of serious COVID outcomes, and were also advised to self-isolate,” noted the investigators.
Univariable ordinal logistic regression of serious events revealed that male gender, older age, progressive disease, not being on an active DMT regiment, severe disability, and comorbidity presence were all confirmed to be significant factors associated with hospitalization (P < .01). Multivariable analysis, however, found that only age and male gender were significant.
However, factors associated with adverse outcomes were not predictive of mortality once hospitalization occurred, implying that in-hospital factors that were not quantified in the study may be more predictive of mortality, according to the investigators.
When comparing the first and second waves, the likelihood of hospitalization and death due to COVID-19 decreased during the second wave (P < .001 and P = .02, respectively).
The investigators listed some study limitations, including that the data capture tool was devised at the outset of the pandemic and therefore did not capture information on ethnicity, body mass index, and other factors that have been shown in the months since to be associated with increased mortality for people with COVID-19. There was also limited availability of polymerase-chain reaction testing in the first few weeks of the pandemic and a potential reporting bias.
Middleton RM, Craig EM, Rodgers WJ, et al; UK Multiple Sclerosis Register Research Group COVID-19 in Multiple Sclerosis: Clinically reported outcomes from the UK Multiple Sclerosis Register. Mult Scler Relat Disord. Published online October 8, 2021. doi:10.1016/j.msard.2021.103317