Researchers conducted a retrospective cohort study using an Israeli administrative claims database in which they analyzed the incidence of PsA in 58,671 patients who were first diagnosed with psoriasis between January 1, 2000, and December 31, 2020.
Patients were categorized by treatment regimens: Biologics, methotrexate, phototherapy, or topical treatments. Patients in the phototherapy and topical therapy groups did not receive any systemic treatments prior to enrollment in the study, which followed patients until PsA diagnosis, treatment was switched, death, or the end of the study on February 10, 2022.The methotrexate group showed the highest PsA incidence, followed by the anti-interleukin -12/23, anti-IL-17, phototherapy, and tumor necrosis factor inhibitor groups.
All biologic treatment groups collectively showed a reduced risk for PsA compared with the methotrexate group . Biologic treatments were associated with a notably higher risk for PsA than topical therapy .The investigators did not have access to Psoriasis Area and Severity Index scores, and so disease severity and other potential confounding factors and sources of bias may have influenced the association such that the use of biologic agents could be seen not as a cause but rather as a marker for more severe disease characteristics.