Longitudinal modeling of upper extremity function in multiple sclerosis: Associations for clinical and sociodemographic factors

Abstract

Background: Upper extremity impairment is a common disabling consequence of multiple sclerosis (MS). Little is known about factors influencing upper extremity functioning in MS. Objective: Identify associations with longitudinal changes in upper extremity performance. Methods: Using a real-world, retrospective cohort study (4140 persons with MS and 14,544 observations), multivariable repeated-measures analyses were completed for nine-hole peg test (9HPT) dominant and non-dominant hand times and their difference (asymmetry), with clinical, demographic, and social determinants as covariates. Interactions with time (disease duration) were examined. Results: Cross-sectionally, dominant, and non-dominant hand times were strongly correlated (ρ = 0.78), and moderately correlated with asymmetry, walking speeds, and depressive symptoms. Longitudinally, older age, males, Hispanics, Blacks, ever smokers, public insurance beneficiaries, greater lower-limb impairment, progressive disease, and greater depressive symptoms were independently associated with worsening dominant and non-dominant times. Public insurance beneficiaries, greater lower-limb impairment, progressive disease, and greater depressive symptoms were associated with greater asymmetry. Males accrued dominant hand dysfunction more rapidly and had greater asymmetry than females over time, while those with increasing lower-limb impairment more rapidly experienced asymmetry over time. Discussion: These findings identify high-risk groups and inform future research to guide strategies for preserving upper extremity function in multiple sclerosis.