Healthcare costs of inflammatory myopathies

Little information exists regarding the economic burden related to inflammatory myopathies. Our objective was to estimate health services costs in a large, unselected, population-based sample of patients with inflammatory myopathies.

We identified subjects with polymyositis and dermatomyositis from administrative healthcare databases (covering all beneficiaries, about 7.5 million) in Quebec province, Canada. Average estimates of health services costs (physician visits, diagnostic tests and procedures, outpatient surgeries and procedures, acute care hospitalizations) for 2003 were calculated by multiplying health service use levels by the appropriate unit prices, determined from government fee schedules and other sources. Multiple linear regression analyses were performed to establish whether specific factors (age, sex, disease duration, region of residence, socioeconomic status, type of myositis, disease severity) were associated with cost.

We identified 1102 subjects with inflammatory myopathy from January 1, 1989, to January 1, 2003. About two-thirds were women (68.9%); average age at case ascertainment was 57.4 years (SD 18.4). The average cost of all reimbursed health services, in 2008 Canadian dollars, was $4099 per patient (SD $9639). Costs increased with age, and were highest early in the disease course. Greater disease severity (defined as the need for prior hospitalization for myositis) was also a strong predictor of both physician costs and total costs.

These results indicate significant economic burden related to inflammatory myopathies, with important demographic predictors. Our estimates suggest that the health services costs in inflammatory myopathies may equal, or exceed, those of other serious diseases, such as rheumatoid arthritis and systemic sclerosis.