Disposable income trajectories of working-aged individuals with diagnosed multiple sclerosis

The economic situation of individuals diagnosed with multiple sclerosis (MS) is under studied, with the levels and sources of incomes suggested to vary with socio-demographics. We aimed to describe the diversity of disposable income (DI) trajectories among working-aged individuals with incident MS, and investigate the associations of socio-demographic characteristics with identified trajectories.

A population-based cohort study of all 1528 individuals first diagnosed with MS in 2008-2009 when aged 25-59, with data linked from three nationwide Swedish registers. DI was defined as net earnings plus net income from benefits. Trajectories of mean annual DI from 7 years prior to 4 years after diagnosis were identified by group-based trajectory modelling. An individual's group membership was determined by individual model-fit estimates from a multinomial logit function. Chi-squared tests and multinomial logistic regressions estimated the associations between trajectory membership and socio-demographic (sex, age, education, birth country, type of living area and family situation) and work disability (sickness absence and disability pension) characteristics.

Seven distinct DI trajectories were identified: two consistently low (50.7% of individuals); four increasing (39.0%); and one decreasing (10.3%). Socio-demographic and work disability characteristics were associated with trajectories; the increasing trajectories had older age-profiles and higher proportions of men, while university education was less common in the consistently low trajectories.

We identified high diversity in DI development within the cohort around MS diagnosis. Socio-demographic and work disability characteristics differed between the trajectories. This broader information of the economic situation is important to convey to patients.