Systemic lupus erythematosus with neuropsychiatric manifestation incurs high disease costs: a cost-of-illness study in Hong Kong

Objective. To determine the direct and indirect costs of SLE in Hong Kong, and to ascertain the relationship between neuropsychiatric SLE (NPSLE) and disease costs. Methods. A retrospective, cross-sectional, non-randomized cost-of-illness study was performed in a tertiary rheumatology specialty centre in Hong Kong. Participants completed questionnaires on sociodemographics, employment status and out-of-pocket expenses. Healthcare resources consumption was recorded by chart review. The occurrence of NPSLE since onset of SLE was determined using the 1999 ACR nomenclature and standard definitions. MannWhitney U-test was used to compare disease costs between patients with and without NPSLE. Multiple linear regression was used to determine the predictors of the costs. Results. Three hundred and six Chinese patients were recruited, with a mean age of 41 years and mean disease duration of 9.6 years. A total of 108 NPSLE events were recorded by 83 patients. The most common manifestations were seizure and cardiovascular disease. The mean annual total costs were USD 13 307 per patient. The direct costs dominated the total costs, and the costs of inpatient care contributed 52 of the direct costs. Patients with NPSLE incurred significantly higher direct and indirect costs compared with those without NPSLE. The number of NPSLE events was an independent explanatory variable associated with both direct and indirect costs. Conclusion. The economic impact of SLE in Hong Kong is considerable and patients with NPSLE incur higher disease costs compared with those without NPSLE. Improvement in prevention of end-organ damage, especially neuropsychiatric manifestation, may reduce costs of SLE patients.