Estimating Indirect Costs in Primary Sjögren's Syndrome

Objective. To estimate the indirect costs associated with primary Sjögren's syndrome (pSS) compared with rheumatoid arthritis (RA) and community controls. Methods. Data were obtained from 84 women patients with pSS as part of a study to develop a systemic activity measure, from 87 consecutive women patients with RAattending a hospital clinic, and from 96 women community controls on a general practice list. A modified economic component of the Stanford Health Assessment Questionnaire was used to assess lost productivity. Results. Using a conservative model, the estimated total annual indirect costs (95% CI) were £7677 (£5560, £9794) for pSS, £10,444 (£8206, £12,681) for RA, and £892 (£307, £1478) for controls. Using a model that maximizes the estimates, the equivalent figures were £13,502 (£9542, £17,463), £17,070 (£13,112, £21,028), and £3382 (£2187, £4578), respectively. These were all significantly greater at p < 0.001 for patient groups than for the control group. Conclusion. pSS is associated with significantly increased indirect costs equivalent to 69%-83% of that for patients with RA. This needs to be taken into account when evaluating the overall economic consequences of pSS.