Risk of Mortality of People With Psoriasis and Psoriatic Arthritis in Taiwan: A Nationwide Cohort Study.

Objective: Residual confounding effects and disease severity are attributed to controversial results in studies of psoriatic disease (PsD) and mortality. We aimed to evaluate the risk of mortality in patients with incident PsD, compared to matched controls from the population.

Methods: We used the nationwide, population-based insurance claim datasets in Taiwan from 2010 to 2018. Incident cases of PsD were identified by International Classification of Diseases (ICD) codes. A nonexposed cohort was established through propensity score matching (PSM). Deaths were identified via the National Mortality Database. We evaluated the risk of all-cause mortality in PsD compared to the PSM nonexposed individuals using Cox regression. The mortality risk was evaluated in patients with more severe disease stratified by systemic therapy use and having psoriatic arthritis (PsA).

Results: There were 108,642 patients with incident PsD (40.2% women) and an equal number of PSM non-PsD individuals. Compared to the age- and sex-matched controls, there was a higher risk of mortality among patients with PsD (adjusted hazard ratio [aHR] 1.73, 95% CI 1.68-1.77, P < 0.001). After PSM, we found an attenuated but persistent higher risk of mortality in PsD compared to controls (aHR 1.20, 95% CI 1.16-1.24). There was a trend of higher mortality in patients exposed to biologic therapies, but not for PsA.

Conclusion: There was an increased risk of all-cause mortality in individuals with PsD compared to individuals without PsD before and after both PSM and adjustment for comorbidities. The risk of mortality was higher in patients with psoriasis but not in patients with PsA as compared to controls.