Trends in mortality and cause-specific mortality among patients with psoriasis and psoriatic arthritis in Ontario, Canada.

BACKGROUND: There is limited information about mortality rates among patients with psoriasis and psoriatic arthritis (PsA) in North America and their change over the past 2 decades. OBJECTIVE: To compare all-cause and cause-specific mortality rates in patients with psoriasis to the general population in Ontario, Canada, from 1996 to 2016. METHODS: We conducted a population-based, retrospective cohort study of adult residents using administrative health data. All-cause and cause-specific standardized mortality rates, standardized mortality ratios, and excess mortality rates were calculated. RESULTS: 176,858 (2,524 deaths) patients with psoriasis and 15,430 (221 deaths) patients with PsA were identified in 2016. Patients with psoriasis and PsA had standardized excess mortality rates of 1.44 and 2.43 per 1000 population, respectively. Standardized mortality rates decreased by approximately 30% over the study period in both disease groups but remained significantly elevated compared to the general population. The leading causes of death in psoriasis and PsA patients were cancer, circulatory disease, and respiratory conditions. LIMITATIONS: We were unable to classify patients according to disease severity. CONCLUSIONS: Despite improvements in psoriasis treatment, the relative excess mortality, which may be related to risk factors for psoriatic disease, remained unchanged, with an average of approximately 1 to 2 extra deaths per 1,000 patients in 2016.