Mortality studies in psoriatic arthritis: Results from a single outpatient clinic. I. Causes and risk of death

Abstract

Objective. To identify the causes of death and mortality risk in patients with psoriatic arthritis (PsA) who were being followed up at a single outpatient clinic in Toronto, Ontario, Canada. Methods. Patients enrolled in the PsA Clinic between 1978 and 1993 were compared with the general population of Ontario. Deaths were identified from the clinic database and through linkage with the provincial mortality database, and causes were confirmed by death certificates. A standardized mortality ratio (SMR) was computed, based on the assumption that patients lost to followup were alive at the end of the study. Results. Of the 428 patients with PsA (194 women and 234 men), 53 (26 women and 27 men) died. The 4 leading causes of death were diseases of the circulatory (36.2%) or respiratory (21.3%) system, malignant neoplasms (17.0%), and injuries/poisoning (14.9%). The SMR for the female cohort was 1.59, and for the men, it was 1.65, indicating a 59% and 65% increase in the death rate, respectively. Deaths due to respiratory causes were particularly increased in these patients. Conclusion. The results suggest that this PsA Clinic outpatient population had an increased mortality risk.