Multiple sclerosis (MS) is a costly chronic disease that tends to have an early onset, with most patients diagnosed between 20 and 40 years of age. Due to its onset during a patient’s most productive working years, social costs associated with productivity loss add to the already amounting direct and indirect medical expenditures.
MS is a neurologic autoimmune disease in which the immune system attacks and degrades myelin sheaths on axons in the brain, spinal cord, and optic nerves. It is the leading cause of nontraumatic neurologic disability in young adults in the United States and Europe. For treatment, disease-modifying therapies (DMTs) have been found to reduce relapses and slow disability progression due to relapses with incomplete recovery, and DMTs are also known to reduce relapse-associated costs.
In general, MS is associated with high direct and indirect costs, with direct costs consisting of expenditures such as hospitalizations, inpatient and outpatient care, and pharmaceuticals. Indirect costs consist of short- and long-term disability, disease-related absences from work, workers’ compensation, and early retirement.
In a recent literature review by Gabriel Adelman et al, the researchers sought to estimate the average annual cost per MS patient in the United States using previously published literature. The review was reported in the Journal of Medical Economics [2013. doi:10.3111/13696998.2013.778268].
The researchers conducted this literature review by searching PubMed and Embase using the search term “multiple sclerosis” in conjunction with the medical subject heading “healthcare costs.” The search was limited to English-language studies published between January 1, 2007, and June 21, 2012. After eliminating published studies due to search criteria—such as review articles, duplicate articles, studies without full text available, and studies based outside of the United States—15 articles remained and were used as a part of this literature review. Eight studies presented only direct cost calculations, and the remaining 7 presented estimates of total cost, broken down into direct and indirect costs.
Cost data were extracted from the literature and evaluated in the following ways: (1) mean total, direct, and indirect costs were calculated; (2) direct and indirect costs were calculated as a percentage of the total cost; and (3) the percentage of total cost attributable to each specific cost component was calculated. Costs were then converted from “cost year” (the year in which the figures were reported) to 2011 dollars using the medical component of the Consumer Price Index.
Five of the studies in this review calculated the percentage of costs attributable to direct and indirect costs as well the cost of DMTs as a component of direct cost. Based on these 5 studies, direct costs comprised 77% of the total costs, on average, ranging from 64% to 91%, with prescription medication accounting for the majority of direct costs. The indirect costs comprised 23% of the total costs, on average, ranging from 9% to 36%.
Total mean costs for patients with MS ranged from $8528 to $54,244 per patient per year in 2011 dollars, with direct mean costs ranging from $6144 to $34,511. Indirect costs ranged from $1896 to $19,733 per patient per year in 2011 dollars.
Prescription medications and indirect costs were the largest single cost driver of MS, representing an average of 50% and 23% of total costs, respectively. General healthcare costs, representing a multitude of cost categories, represented an average of 27% of the total costs.
One study included in this literature review evaluated cost by disease type in 2006 dollars, reporting that the direct costs associated with primary progressive MS (PPMS) were approximately 4 times higher than relapsing-remitting MS ([RRMS] $23,630 vs $5887, respectively). For patients with RRMS, per-patient annual direct costs associated during relapse reportedly averaged $17,016, and, during remission, direct costs averaged $7296. Stable RRMS direct costs averaged $3972.
Another study used 14 years of data from the Nationwide Inpatient Sample to estimate the average cost of an MS hospitalization alone was $20,076 in 2006 dollars.
Lastly, another study that was reviewed found that patients adherent to DMTs averaged $3421 in direct medical expenditure over a 12-month period, while nonadherent patients averaged $5179 (in 2009 dollars).
The findings conclude that compared with direct all-cause medical costs for other chronic conditions reported in literature, MS ranked second most costly behind congestive heart failure.
The authors of this literature review cited the following study limitations: (1) data sources were from dated studies, ranging from 1999 to 2008, thus the costs do not reflect newer, more costly therapies; (2) the review does not include assessment of the decrements in quality of life associated with MS or costs associated with increasing levels of disability or early retirement; and (3) variations in study designs, populations, methodologies, and cost inputs preclude more precise cost estimates.
In addition, the researchers suggest further research is needed to understand costs by MS type (RRMS, PPMS, and secondarily progressive MS), costs associated with increasing disability and early retirement, and the potential impact of new treatments expected to launch in the future.