Article Text
Abstract
Objectives To compare productivity costs due to inability to perform paid work for ankylosing spondylitis (AS) in three European countries: the Netherlands (NL), France (F) and Belgium (B).
Methods 216 consecutive prevalent out-patients with AS started a 2 year cost-of-illness cohort study. Questionnaires assessed AS-related health resource utilisation every 2 months. Productivity costs were calculated from societal perspective by friction costs (FC) method (costs of first 3 months of sick-leave) and human capital (HC) approach (costs of sick-leave and work-disability). In addition, loss of income for the patients was assessed. Differences in social security systems among countries were taken into account. Means and 95% CI after bootstrapping are presented. T-tests were performed on the results of the bootstraps to compare countries.
Results 209 patients completed follow-up. In NL, F and B respectively, 70, 69 and 74% were male, mean age 46 (SD:12), 38 (SD:12) and 42 (SD:14) yr, mean disease duration 24 (SD:12), 14 (SD:9) and 13 (SD:10) yr and 24, 13 and 24% had a manual profession.
Conclusion Productivity costs due to AS are substantial for society and patients and differ among countries. FC underestimate the economic impact of disease. These findings have implications for generalizability of economic studies.