Background: In young adults at the height of their economical activity, multiple sclerosis (MS) is the most common disabling neurological disease. From prior research it has been established that MS has vast effects on labor market participation. However, there is a lack of studies investigating the pattern of transitions MS patients make between labor market states.
Objective: To investigate the variation in transitions to sickness absence (SA), rehabilitation (REHAB), disability pension (DP) and return to work (RTW) relative to time with MS.
Method: A Cox proportional hazard rate model for single events is used to study the transition to DP for the Oslo cohort dataset, accounting for the relative impacts of age at onset of disease, type of MS and gender. A competing risk hazard rate model for multiple events is used to study transitions to SA, REHAB, DP and RTW for the FD-Trygd dataset, consisting of MS patients as well as matched control subjects. We account for the impact of time with MS as well as for those of age, gender, education, development over 1992-2008, seasonal dependence and duration dependence for transitions from SA and REHAB spells.
Results: MS has profound impacts on the transitions RTW, SA, REHAB and DP, which are consistently associated with poorer relative outcomes than those of controls. We find substantial effects and differences in intensity of transitions over time. After 17 years approximately 2/3rds of MS patients end up receiving DP, and only a quarter remain working. We uncover variation towards transitions in the age of the subject, the age at onset of MS (only DP), gender, education level, type of MS (only DP), and time with MS. Transition intensities also vary according to season of the year and according to duration of SA and REHAB spell. We find indication that not only onset of MS but also registration of MS with public authorities has profound impacts on the transitions to the various outcome states.
Conclusion: We find that MS patients move dynamically from a start in the state working towards disability pension through spells of SA and REHAB, after onset of disease. Associated with each SA and REHAB spell are the transitions back to work from where they can experience new spells. In between the starting point in the state of working and the final end-point of disability pension MS patients experience different periods that vary in transition-intensity.