Background Psoriatic arthritis (PsA) is an inflammatory condition of the joints that occurs in up to 30% of patients with psoriasis. While the cost of DMARD therapy has previously been described, little is known about the costs of best supportive care following DMARD discontinuation.
Objectives To describe the best supportive care costs of psoriatic arthritis patients following discontinuation of DMARD therapy.
Methods Adult patients with ≥ 2 PsA diagnoses (from office visits) with continuous insurance coverage ≥ 6-month before (baseline period) and ≥ 12-month post-index date were selected from the MarketScan Commercial and Medicare Claims database (2005-2009). The index date was defined as the last day of DMARD coverage. Discontinuation was defined as no DMARD treatment for ≥ 12 consecutive months from the last day of DMARD prescription coverage. Patients were classified as having discontinued from a biologic if there was evidence of biologic DMARD use during the baseline period; otherwise they were defined as having discontinued from non-biologic DMARD. Twelve-month average costs following discontinuation were reported.
Results A total of 1,656 PsA patients met the selection criteria; 63.2% were discontinued on non-biologic DMARD therapy and 36.8% on biologic therapy. Of non-biologic DMARD users, 59.7% were on methotrexate and 40.3% on other DMARDS. Over the 12-month period following discontinuation, total costs were $14,359 (SD: 23,375) and $10,144 (SD: 17,312) for biologic and non-biologic discontinuers, respectively (p< 0.001). Outpatient and hospital/ER costs were significantly higher for the biologic discontinuers compared to the non-biologic discontinuers ($7,606 vs. $5,429, p=0.002, and $3,439 vs. $2,066, p=0.013, respectively) and accounted for 77% and 74% of total costs, respectively. Similarly, biologic discontinuers had higher drug costs ($3,314 vs. $2,649, p=0.002) and longer mean length of hospital stay (1.16 days vs. 0.71 days, p=0.012, respectively).
Conclusions This study suggests that outpatient and hospital/ER costs account for a substantial proportion of health care costs in PsA patients who discontinued from DMARD therapy. Patients who had discontinued from biologic DMARD therapy incurred higher outpatient, hospital and drug costs and longer hospital stays compared to patients who had discontinued from non-biologic DMARD therapy.
Disclosure of Interest T. Tencer Employee of: Celgene Corporation, S. Li Consultant for: Celgene Corporation, F. Zhang Employee of: Celgene Corporation