**4. Materials and Methods**

The present Delphi method followed the recommendations of a systematic review for the development of healthcare quality indicators [51]. Six urologists designed the study into three separate work packages: definition of complexity, outline of the factors that drive complexity and evaluation of their respective contributions in clinical scenarios. Four panellists were then invited to broaden the scope of ages and experiences (Table 4). As a whole, the panel comprised 10 board-certified urologists with over 202 years of combined experience.


**Table 4.** Panel participants' characteristics and experience in urology.


**Table 4.** *Cont.*

\* Years since board certification, that is, 202 years of combined experience in urology and 160 years in oncology. \*\* Years since head of department or unit. FEBU: Fellow of the European Board of Urology, ESU European School of Urology, YAU: Young Academic Urologists, ESOU: European Society of Oncologic Urology, NMIBC: non-muscle invasive bladder cancer, MIBC: muscle-invasive bladder cancer.
