Reply to Satoshi Funada, Takashi Yoshioka, and Yan Luo's Letter to the Editor re: Ashley M. Hopkins, Ganessan Kichenadasse, Christos S. Karapetis, et al. Concomitant Antibiotic Use and Survival in Urothelial Carcinoma Treated with Atezolizumab. Eur Urol 2020;78:540–3

We thank Funada et al for the comments on our Brief Correspondence in European Urology [1]. We agree that established guidelines for subgroup analyses are critical for promoting valid assessment of treatment effect heterogeneity and note that the comments (ie, the importance of clearly stating the post hoc nature of analysis, having a clear basis for undertaking the subgroup analysis, using a statistical test of treatment-by-covariate interaction, and cautious interpretation of findings) simply restate the existing appropriate methods, interpretation, and reporting in our manuscript [1]