The economic burden of disease: comparison between rheumatoid arthritis and ankylosing spondylitis.

During the last decade the economic burden of rheumatic diseases has been increasingly recognised. Even though more studies have been published on rheumatoid arthritis (RA) than ankylosing spondylitis (AS) sufficient data is available for comparison of some economic consequences. This overview addresses mainly the societal impact of RA and AS on (1) labour force participation, on (2) the costs of healthcare consumption and reduced productivity and on (3) health in terms of QALY.In order to examine labour force participation comparison with the general population is preferable. These studies demonstrate increased withdrawal from work in both diseases but more frequently in RA. Risk factors for reduced labour force participation in RA and AS are longer disease duration, lower education and unfavourable labour market conditions. The influence of the sex on employment depends on several factors such as the type of disease and the labour force participation of the general population.In RA overall mean direct costs of healthcare consumption and indirect costs of reduced productivity are above that of AS, particularly after long disease duration. Out-of-pocket expenditures costs were higher in females RA patients than in males while this was less clear in AS. The main cost driver in both diseases for all type of costs was reduced physical function.The societal valuation of health (utility) showed similar reductions of quality adjusted life years (QALYs) in RA and AS when compared with the general population.In conclusion, while the societal valuation of the impact of both diseases on health is similar, the decrease in worker participation is more pronounced in RA and direct as well as productivity costs are higher. However, since AS starts at an earlier age, the lifetime economic burden might be higher. There is a strong relation between physical function and each aspect of economic impact.