Cohort study on the survival of methotrexate and acitretin treatment in patients with plaque psoriasis: experience from a single center

Cohort study on the survival of methotrexate and acitretin treatment in patients with plaque psoriasis: experience from a single center Dear Editor, Psoriasis is an inflammatory, immune-mediated, multifactorial, chronic disease of universal occurrence. 1 An estimated 125 million individuals are affected worldwide, with five million of them in Brazil alone. 2,3ts treatment is based on topical active ingredients for mild cases; however, phototherapy, systemic drugs such as cyclosporine, methotrexate (MTX), acitretin (ACT), immunobiologicals, and small molecules are reserved for moderate and severe forms. 3s with other chronic diseases, continuity of therapy is an important aspect in the remission of clinical manifestations.The duration of use of a medication, known as therapeutic survival, is an indicator of its overall effectiveness, reflecting aspects such as adherence, side effects, cost, access, and patient and physician satisfaction. 4,5n Brazil, MTX and ACT are first-line therapies for the treatment of moderate to severe psoriasis, available through the Brazilian Unified Health System (SUS, Sistema nico de Sade).However, to date, there are no studies addressing the survival of these drugs in our population or the factors that affect treatment continuity.With these objectives in mind, a real-world study was conducted with a bidirectional cohort design, based on the analysis of medical records of patients with psoriasis vulgaris who used MTX or ACT as systemic monotherapy at the public psoriasis outpatient clinic of Hospital das Clnicas, FMB-Unesp (Botucatu, SP).The protocol was approved by the institutional ethics committee, and data collection included the analysis of medical records of patients treated between January 2012 and July 2024.Survival curves were estimated using the Kaplan-Meier method, and comparisons between groups were performed using the log-rank test.The