Cost-of-illness of rheumatoid arthritis and ankylosing spondylitis

To assess, quantify and summarise the cost of illness of rheumatoid arthritis (RA) and ankylosing spondylitis (AS) from the societal perspective. Original studies reporting costs of RA or AS were searched systematically. Both cost-of-illness studies and economic evaluations of therapies were included. Studies were appraised for patient and study characteristics, type of costs and actual costs. Reported costs were aggregated by cost categories and overall mean costs were summarised by cost domain (healthcare, patient and family, and productivity costs). Overall mean costs of RA (euro14,906 per year) were above that of AS (euro9,374 per year), while the relative distribution of costs over cost domains was approximately similar. For both diseases, productivity costs based on the human cost approach were 3 to 10 times higher than the friction costs and accounted for more than half the total costs of both diseases. Productivity costs constitute the largest part of the total cost-off-illness of RA and AS reflecting the high burden of the disease on work participation. Although total and direct costs of illness in RA were higher than in AS, the average age of AS patients was 10 years lower and therefore, lifetime costs associated with AS may actually be equal or higher.