Objective: To assess the effects of mobility loss on instrumental activities of daily living (IADL) and socioeconomic status in multiple sclerosis (MS) patients.
Methods: Participants were active registrants in the North American Research Committee on Multiple Sclerosis registry completing the Fall 2006 (IADL analysis, n = 10,396) or Spring 2007 (socioeconomic analysis, n = 8180) surveys. Cross-sectional correlations and linear and logistic regression were performed using sociodemographic factors, mobility scales, and Patient Determined Disease Steps as independent variables and IADLs as the response.
Results: Mobility loss was significantly correlated with decreased IADL scores (r = -0.74; p < 0.0001); this correlation remained significant after adjustment for covariates. Mobility loss also negatively correlated with employment (r = -0.48 for women; r = -0.50 for men, both p < 0.0001) and annual income (r = -0.29; p < 0.0001). These correlations were all significant even with mild mobility loss. The relationships derived from the regression models suggest that the effect of mobility on employment is greater than the effect of demographic variables, and a small but direct effect on annual income that is independent of effects mediated through employment. The self-reported diagnosis of MS for study inclusion and use of single-item ordinal scales for mobility and disability can potentially be criticized as study limitations, although the diagnosis and the scales were previously validated.
Conclusion: Mobility loss independently correlated with IADL, and associated with reduced socioeconomic status in people with MS. These correlations were significant with mild mobility loss, supporting early treatment.