Healthcare and burden of disease in psoriatic arthritis. A comparison with rheumatoid arthritis and ankylosing spondylitis

OBJECTIVE: To compare quality of life and treatment among patients with psoriatic arthritis (PsA), rheumatoid arthritis (RA), and ankylosing spondylitis (AS) treated by German rheumatologists. METHODS: Data for outpatients with PsA (n = 1863), RA (n = 9627), or AS (n = 1378) enrolled in the national database of the German collaborative arthritis centers in the year 2002 were analyzed. Among those with PsA, 2 subgroups with predominantly peripheral arthritis (n = 1612) and predominantly axial disease (n = 251) were distinguished. RESULTS: We found a high burden of illness in patients with PsA treated by rheumatologists. Among the 2 subgroups, those with axial PsA had worse outcomes (pain, function) than those with peripheral PsA. However, compared with RA and AS, physician ratings of disease activity and severity were lower in PsA. Concerning access to rheumatology care, there were similarities between AS and axial PsA, with very long disease duration at first visit (mean of about 6 yrs), versus RA and peripheral PsA, with shorter duration (1.6 and 2.5 yrs, respectively). A majority (84%) of patients with PsA were treated with disease modifying antirheumatic drugs. Thirty percent of the patients with PsA currently were under therapy with glucocorticoids, mainly (89%) with a dose < 7.5 mg. CONCLUSION: Patients with PsA seen in rheumatologic care have a burden of illness comparable to that of patients with RA or AS.