Nix 2010.

Methods	Study design: randomised noninferiority single‐centre study Study period: April 2008 and January 2009 Study setting: hospital based –University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA LN yield was selected as the primary end point used for power analysis The null hypothesis was that mean LN yield for open cystectomy was higher than that for robotic cystectomy. A sample size of 20 participants per arm was calculated to provide 80% power and a 0.05 type 1 error rate to demonstrate the noninferiority of open to robotic cystectomy with respect to LN count based on a critical difference of 4 LNs. The 90% one‐sided CI of this difference is reported because of the 5% significance used for the sample size calculation. If the upper level of this CI is > 4, the null hypothesis cannot be rejected and noninferiority has not been achieved.
Participants	Adults undergoing radical cystectomy (n = 41) Diagnostic and inclusion criteria: Clinically localised urothelial carcinoma of the bladder Decision for surgical candidacy was based on the participant’s overall health status primarily with regard to ability to tolerate the pneumoperitoneum and steepness of the Trendelenburg position associated with the robotic approach. Exclusion criteria: Unsuitable surgical candidates for either approach Those not allowing randomisation Those with preconceived preference for a specific surgical modality
Interventions	Cohort 1 = ORC with urinary diversion and PLND (n = 20) Cohort 2 = RARC with extracorporeal urinary diversion and PLND (n = 21) Lymphadenectomy template: obturator, external iliac, hypogastric, and common iliac LN chains (did not include a paraaortic or paracaval dissection) Surgeon experience: Experience of > 75 robotic cystectomy cases and of > 400 open cystectomy procedures Same primary surgeon and experienced surgical team in both groups Demographic data: RARC vs ORC Mean age years = 67.4 vs 69.2 Male:Female = 14:7 vs 17:3 Body mass index, kg/m², mean = 27.5 vs 28.4
Outcomes	EBL Operative time Complications Recovery of bowel function Narcotic usage Length of stay when assessed Margin status Lymph node count Time to adjuvant chemotherapy
Funding sources	None
Declarations of interest	None
Notes	Language of publication: English
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote from publication: "The randomizations schema was performed with five sequential patients undergoing an approach before alternating surgical modality." Comment: random sequence generation adequate
Allocation concealment (selection bias)	High risk	Quote from publication: "The randomization schema was performed with five sequential patients undergoing an approach before alternating surgical modality. This scheme was chosen, as opposed to randomizing each sequential patient, for the purpose of resident education. We believed that alternating each sequential surgery as to approach would make it significantly more difficult for residents to progress through their knowledge and acquisition of proficiency in each of the individual procedures." Comment: allocation concealment inadequate
Blinding of participants and personnel (performance bias)	High risk	Comment: participants and personnel not blinded
Blinding of outcome assessment (detection bias) Recurrence Free Survival	Unclear risk	Comment: not reported
Blinding of outcome assessment (detection bias) QOL	Unclear risk	Comment: not applicable as not reported
Blinding of outcome assessment (detection bias) Complications	Unclear risk	Comment: no report on who collected outcomes and if they were blinded to the procedure
Blinding of outcome assessment (detection bias) Transfusion Rates	Unclear risk	Comment: not applicable as not reported
Blinding of outcome assessment (detection bias) Hospital Stay	Low risk	Comment: unlikely to be affected by nonblinding
Blinding of outcome assessment (detection bias) Positive Margin Rates	Low risk	Comment: unlikely to be affected by nonblinding
Incomplete outcome data (attrition bias) Complications/Transfusion/Hospital Stay/Positive Margins	Low risk	Comment: all randomised participants included in analysis for these outcomes
Incomplete outcome data (attrition bias) QOL	Unclear risk	Comment: not applicable as not reported
Incomplete outcome data (attrition bias) Recurrence Free Survival	Unclear risk	Comment: not reported
Selective reporting (reporting bias)	Unclear risk	No protocol published
Other bias	Low risk	None