Costs and quality of life of multiple sclerosis in Spain

Abstract

This cost-of-illness analysis is based on information from 1.848 patients in Spain and is part of a Europe-wide study on the costs of multiple sclerosis. The objective was to analyze the costs and quality of life (QOL) related to the level of disease severity and progression. Patients were identified by the Asociación Española de Esclerosis Múltiple (AEDEM) and participated in the survey by answering a mail questionnaire (response rate 31.8%). In addition to details on the disease (type of disease, relapses, level of functional disability), the questionnaire asked for information on all resource consumption, medical, non-medical, work absence and informal care, as well as utility (QOL). The mean age of the cohort was 45 years, and only 5.5% of patients were 65 years of age or more. Approximately 36% of patients had mild disease (Expanded Disability Status Scale [EDSS] score of 0–3), 44.8% had moderate disease (EDSS score of 4–6.5) and 17.7% had severe disease (EDSS score ≥7). The mean EDSS score in the sample was 4.5 (median 5.0), with a utility of 0.554. Costs and utility are highly correlated with disease severity. Workforce participation decreases from around 70% in early disease to less than 5% in the very late stages. Hospitalization is very infrequent in early disease, representing less than € 1.300 per patient per year for patients at EDSS scores <6, but increases steeply for patients at scores ≥7. Ambulatory care increases fivefold between early and late disease, while investments and services increase from basically no cost to just over € 6.000 at EDSS scores ≥7. Productivity losses increase more than eightfold, and informal care increases from € 593 at EDSS scores of 0–1 to nearly € 34.228 at scores of 8–9. Hence, total mean costs per patient are driven by the distribution of the severity levels in the sample, increasing from € 10.425 at EDSS scores of 0–1 to € 45.264 at a score of 7, and € 65.693 at scores of 8–9. The same is true for utility, which decreases from 0.865 to 0.084 as patients progress from the mildest to the most severe disability levels. However, the utility loss compared to the age- and gender-matched general population is high at all levels of the disease (∼0.25 in patients below 30 years of age with an EDSS score of 2–3, and ∼0.4 in patients over 60 years of age and a score of ≥6), leading to an estimated annual loss of 0.276 quality-adjusted life-year per patient. Relapses for patients with an EDSS score below 5 are associated with a cost of approximately € 2.750 and a utility loss of 0.1 during the quarter in which they occur.