Evaluation of the Economic Burden of Psoriatic Arthritis and the Relationship Between Functional Status and Healthcare Costs.

Objective: This analysis aimed to evaluate the economic burden of patients with psoriatic arthritis (PsA) on the UK healthcare system and estimate the relationship between functional status and direct healthcare costs.

Methods: Functional status [measured using the Health Assessment Questionnaire-Disability Index (HAQ-DI)], demographics, disease history, and healthcare resource use data were extracted from a cohort of patients at the Royal National Hospital for Rheumatic Diseases, Bath, UK. Each resource use item per patient was then allocated a unit cost. Linear regression models were used to predict costs as a function of HAQ-DI. Medication costs were not included in the primary analysis, which was carried out from the UK National Health Service perspective.

Results: Data were available for 101 patients. Mean HAQ-DI score was 0.84 (SD 0.75) and mean age at HAQ-DI measurement was 57.8 (SD 10.7). Total annual healthcare costs per patient, excluding medication costs, ranged between £174 and £8854, with a mean of £1586 (SD £1639). A 1-point increase in HAQ-DI score was associated with an increase in total costs of £547.49 (standard error £224), with secondary care consultations appearing to be the primary factor. Subgroup analyses suggested higher cost increases in patients with HAQ-DI scores of 2-3 and with a disease duration > 10 years.

Conclusion: Patients with PsA place a significant economic burden on the healthcare system. Functional status is highly correlated with costs and appears to be driven mainly by the cost of secondary care consultations. Results were similar to previous studies in rheumatoid arthritis populations.