Impact of the COVID-19 Pandemic on Personal Networks and Neurological Outcomes of People with Multiple Sclerosis: A Case-Control Cross-sectional and Longitudinal Analysis.

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 â€" 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 networks of both pwMS and controls experienced an increase in constraint (pwMS p=.006, control p=.001) as well as a decrease in network size (pwMS p=.003, control p<.001), effective size (pwMS p=.007, control p=.013), maximum degree (pwMS p=.01, control p<.001), and percent contacted weekly or less (pwMS p<.001, control p<.001), suggesting overall network contraction during the COVID-19 pandemic. There was also an increase in percentage of kin (p=.003) in the networks of pwMS but not controls during the COVID-19 pandemic when compared to the pre-pandemic baseline. These changes in personal social network due to the pandemic were not associated with worsening neurological disability during the pandemic. Conclusions: Our findings suggest that perceived negative health influences in personal social networks are associated with worse disability in all participants during the COVID-19 pandemic. Despite the perturbation in social environment and connections during the pandemic, the stability in neurological function among pwMS suggests potential resilience.