Costs of rheumatoid arthritis in Germany: a micro-costing approach based on healthcare payer's data sources.

Objective: To develop a systematic set of German cost data in rheumatoid arthritis (RA) based solely on valid healthcare payer's cost data sources.

Methods: Retrospectively one year cost data of 338 patients with RA were generated and analysed. The cost data were derived from a major statutory health insurance plan ("Allgemeine Ortskrankenkasse Niedersachsen") and the regional physicians' association ("Kassenärztliche Vereinigung Niedersachsen"). The recently published matrix of cost domains in RA was applied to structure the analysis. Descriptive statistics were used to analyse the data.

Results: The total direct costs for the 338 patients during one year (third quarter 2000 to second quarter 2001) were euro 3815 per patient-year. RA related direct costs were euro 2312 per patient-year. Outpatient costs accounted for 73.7%, inpatient costs for 24.0%, and other disease related costs for 2.3% of RA related direct costs. Outpatients cost drivers were RA related drugs (euro 1019 per patient-year), physician visits (euro 323 per patient-year), diagnostic and therapeutic procedures and tests (euro 185 per patient-year), and devices and aids (euro;168 per patient-year). 98 patients were retired prematurely owing to RA related work disability and incurred costs of euro;8358 per retired patient-year. 96 patients were gainfully employed and incurred sick leave costs of euro 2835 per employed patient-year.

Conclusion: Micro-costing based on healthcare payer's data provides a relatively conservative albeit highly accurate estimate of costs in RA. Both RA related and non-RA related costs must be taken into account. In gainfully employed patients and in patients who receive RA related retirement payments productivity costs exceed direct costs.