Impact of Multiple Sclerosis Disease Type on Productivity in a Propensity-Matched Cohort of Narcoms Participants
The chronic nature of multiple sclerosis (MS) coupled with the typical onset of disease between ages 20-40 years adversely affects employment; however, the effect of primary progressive MS (PP) on employment is less understood.
To compare employment status of persons with PP vs those with relapsing remitting (RR) or secondary progressive MS (SP).
We conducted a cross-sectional comparison using the Spring 2015 semi-annual survey data from the NARCOMS Registry. We identified participants from US and Canada who reported having RR or SP (Group 1) or PP (Group 2), and restricted the cohorts to participants of working age (18-65 years). Participants in the 2 groups were propensity score-matched on age, disability status as measured by Patient Determined Disease Steps (PDDS), and gender. Differences in the matched populations were examined with respect to employment variables using Chi square or ANOVA, as appropriate.
Of participants who completed the survey, 5148/8004 met the inclusion criteria (3700 [71.8%] RR, 1107 [21.5%] SP and 341 [6.7%] PP). The matching process retained 648 participants (157 [24.2%] RR, 168 [25.9%] SP, 323 [49.9%] PP). The study population was on average (SD) 58 (6) years of age with a median PDDS of 4 (IQR, 3-5); 58.1% were female. The proportion currently employed (22.5%, RR/SP; 17.3%, PP) did not differ between the groups, nor did full- or part-time status among those employed (full: 67.1%, RR/SP; 57.1%, PP). Among those currently employed, no differences were found in hours worked per week, reduced hours, or missed work days. Marital status, type of residence, and annual household income were also similar. However, physical quality of life (QoL; RAND-12 physical) was lower for those with PP vs RR/SP (32.9 vs 30.9, p=0.008). The physical functioning (p<0.0001), role functioning (physical, p<0.0001) and social functioning (p=0.0136) scores were also lower for PP.
Those with PP faced employment-related issues at the same frequency as those with RR or SP of similar age and disability level. However, several QoL domains were worse in the PP group. The similarities in employment status and productivity between the age- and disability-matched groups demonstrate the employment potential among those with PP, underscoring the unmet need for effective treatments. Whether earlier accrual of disability in PP has a greater effect on employment at younger ages than in RR/SP should also be investigated.