Socioeconomic burden of psoriatic arthritis in Hong Kong: direct and indirect costs and the influence of disease pattern.

OBJECTIVE: To estimate the direct costs and indirect costs of patients with psoriatic arthritis (PsA) in Hong Kong. METHODS: A retrospective cost-of-illness study was performed on 125 patients with PsA. Participants completed questionnaires on demographics, employment status, and out of pocket expenses. Health resources consumption was recorded by chart review and patient self-report questionnaire. Patients were grouped according to disease pattern, i.e., peripheral and axial disease. Multiple regression was used to determine the predictors of the costs. RESULTS: The average annual direct costs were $4,141 (2006 US dollars) per patient. Costs of inpatient care accounted for 27% of direct costs, followed by costs of visits to healthcare providers (25%). The estimated average indirect costs were $3,127 per patient-year. Forty-eight (42%) patients had no indirect costs. Sixty percent of patients with peripheral disease were still employed, compared to 39% of patients with axial disease. Patients with axial disease had almost twice the indirect costs compared to those with peripheral disease (p = 0.005). Increased pain and poor function were independently associated with increased direct costs. Worse physical health status, determined by indirect costs borne by the patient, and poor function and old age predicted high costs. CONCLUSION: PsA imposes substantial economic burden. Pain and function are significantly associated with costs. Improvements in treatments to reduce pain and restore function are likely to reduce the costs incurred by these patients.