Performing a multivariate Cox proportional hazard regression with sex and age, sex proved to be an independent variable (HR 2.45; 95% CI 1.63–3.70; p < 0.001), whereas age was borderline significant (HR 0.88; 95% CI 0.77–1.001; p = 0.050).
The higher risk of irTAEs for females is likely to be due to a preponderance of autoimmune diseases in females compared to males [ 15 ] and the borderline significance of younger age as an independent risk factor for irTAE in unknown, but it has been suggested that it could at least partly be explained by relationship between thyroid diseases and younger women [ 15 ].