Impact of the COVID-19 Pandemic on the Personal Networks and Neurological Outcomes of People with Multiple Sclerosis: Cross-Sectional and Longitudinal Case-Control Study

Background: The COVID-19 pandemic has negatively impacted the social fabric of people with multiple sclerosis (pwMS). Objective: To evaluate the associations between personal social network environment and neurological function in pwMS and controls during the COVID-19 pandemic and compare with the pre-pandemic baseline. Methods: We first analyzed data collected from 8 cohorts of pwMS and control participants during the COVID-19 pandemic (March-December 2020). We then leveraged data collected between 2017-2019 in 3 of the 8 cohorts for longitudinal comparison. Participants completed a questionnaire that quantified the structure and composition of their personal social network, including the health behaviors of network members. We assessed neurological disability using three interrelated patient-reported outcomes: Patient Determined Disease Steps (PDDS), Multiple Sclerosis Rating Scale-Revised (MSRS-R), and Patient Reported Outcomes Measurement Information System (PROMIS)-Physical Function. We identified the network features associated with neurologic disability using paired t-tests and covariate-adjusted regressions. Results: In the cross-sectional analysis of the pandemic data from 1130 pwMS and 1250 control participants, higher percent of network members with a perceived negative health influence was associated with greater neurological symptom burden in pwMS (MSRS-R: Beta[95% CI]=2.181[1.082, 3.279], p<.001) and worse physical function in controls (PROMIS-Physical Function: Beta[95% CI]=-5.707[-7.405, -4.010], p<.001). In the longitudinal analysis of 230 pwMS and 136 control participants, the percent of people contacted "weekly or less" (p<.001) decreased during the COVID-19 pandemic for both pwMS (30.34% to 18.78%) and controls (23.48% to 14.89%) when compared to the pre-pandemic period. PwMS further experienced a greater reduction in network size (p<.001), increase in constraint (a measure of close ties of the network, p<.001) and decrease in maximum degree (highest number of ties of a network member, p<.001) than controls during the COVID-19 pandemic. These changes in network features were not associated with worsening neurological disability during the pandemic. Conclusions: Our findings suggest that negative health influences in personal social networks are associated with worse disability in all participants, and the COVID-19 pandemic led to contraction of personal social networks to a greater extent for pwMS than controls.