Reduced risk of mortality associated with systemic psoriasis treatment in the Psoriasis Longitudinal Assessment and Registry (PSOLAR): A nested case-control analysis

Background: The effects of systemic therapy on mortality risk among patients with psoriasis are not fully understood. Objective: To evaluate the impact of systemic treatment on mortality risk in patients enrolled in the Psoriasis Longitudinal Assessment and Registry. Methods: Nested case-control analyses were performed to estimate mortality risk. Cases were defined as patients who died while participating in the Psoriasis Longitudinal Assessment and Registry. Cases were matched (1:4) with controls by age, race, sex, and geographic region. Evaluated treatments included methotrexate, ustekinumab, and tumor necrosis factor a inhibitors. Exposure was defined as at least 1 dose of treatment within 3 months before death and was stratified by duration of therapy. Results: Among 12,090 patients, 341 deaths occurred, matched to 1364 controls. Biologic treatment within the preceding 3 months was protective against mortality versus no exposure: odds ratio (OR) for exposure of less than 1 year, 0.08 (95% confidence interval [CI], 0.03-0.23); OR for exposure of 1 year or longer, 0.09 (95% CI, 0.06-0.13). Methotrexate was protective against mortality only with exposure for 1 year or longer (OR, 0.08; 95% CI, 0.02-0.28). Limitations: Observational studies are subject to unmeasured confounding. Conclusions: Biologic therapy was associated with reduced mortality risk in patients with moderate to severe psoriasis, regardless of treatment duration; methotrexate reduced risk only with exposure for 1 year or longer.