The indirect costs of multiple sclerosis: systematic review and meta-analysis

The aim of this systematic review is to collect and summarize all current data on the indirect costs related to absenteeism and presenteeism associated with multiple sclerosis. Searches were conducted using Medline, Embase and Centre for Reviews and Dissemination databases. All collected costs were recalculated to average annual cost per patient, expressed in 2014 prices US$ using the consumer price index and purchasing power parity (scenario 1) and expressed as proportion of specific gross domestic product in current local currency unit to adjust for country's development (scenario 2). Identified studies were then analyzed in order to assess their possible inclusion in the meta-analysis. The authors identified 63 records, of which 23 were eligible for meta-analysis. Overall indirect cost per patient calculated in scenario 1 was as high as US$20,167 with US$22,197 in Europe, US$17,382 in North America and US$153 in Asia. Overall indirect cost per patient calculated in scenario 2 was equal to US$16,939, with US$19,612 in Europe, US$11,592 in North America and US$899 in Asia. Overall indirect costs varied from US$3726 for patients with EDSS score less than 3 to US$19,264 for patients with Expanded Disability Status Scale score grater that 7. This review revealed the great economic burden of multiple sclerosis on society. The authors observed a great variety of the considered components of indirect costs and their definitions. Costs were higher for Europe than for other continents and were also higher for patients with a higher Expanded Disability Status Scale score.