Differentiating societal costs of disability worsening in multiple sclerosis

J Neurol. 2020 Apr;267(4):1035-1042. doi: 10.1007/s00415-019-09676-4. Epub 2019 Dec 17.


Background: In multiple sclerosis (MS), confirmed disability progression (CDP) can be either the result of progression independent of relapse activity (PIRA) or relapse-associated worsening (RAW). However, the economic effect of PIRA and RAW on societal economic costs in patients with MS is not well understood.

Objective: To determine societal economic costs of patients achieving disease activity free status (DAF) and compare them with those having PIRA and RAW events.

Methods: We used a roving EDSS score analysis to detect PIRA and RAW events with confirmation after at least 6 months. We estimated the age-, gender-, EDSS-adjusted effects of PIRA and RAW on total, direct medical, direct non-medical and indirect societal economic costs. Patients achieving DAF were assigned to as reference.

Results: Overall, 1959 patients were analyzed. Total mean quarterly societal economic costs including disease-modifying therapies (DMTs) were 6929€ (SD: 2886€) per patient averaged over a period of 2 years. Excluding DMTs, patients achieving DAF had total mean quarterly costs of 1703€ (SD: 2489€). PIRA caused 29% (IRR: 1.29; CI 1.06-1.50, p < 0.05) higher total costs compared to DAF. On the contrary, RAW increased total costs by factor 1.56 (CI 1.30-1.87, p < 0.001). The effect of PIRA and RAW was striking for direct medical costs which increased by factor 1.48 (95% CI 1.13-1.95, p < 0.01) and 2.25 (95% CI 1.72-2.94, p < 0.001), respectively.

Conclusion: Disease progression increases societal economic costs significantly. Thus, delaying or even preventing disease progression in MS may reduce the societal economic burden of MS.

Keywords: Cost of illness; Multiple sclerosis; Progression; Resource utilization; Worsening.

MeSH terms

  • Adult
  • Cost of Illness*
  • Disabled Persons
  • Disease Progression*
  • Female
  • Health Care Costs*
  • Humans
  • Immunologic Factors* / economics
  • Immunologic Factors* / therapeutic use
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Multiple Sclerosis, Relapsing-Remitting* / drug therapy
  • Multiple Sclerosis, Relapsing-Remitting* / economics
  • Multiple Sclerosis, Relapsing-Remitting* / physiopathology
  • Multiple Sclerosis, Relapsing-Remitting* / prevention & control
  • Severity of Illness Index


  • Immunologic Factors