Longo 2013.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: parallel group
Participants	Inclusion criteria: people who underwent a TURBT for suspicious bladder cancer diagnosed by WLC Exclusion criteria: not reported  Number randomized: 66 participants to undergo WLC TURBT alone and 71 participants to undergo NBI + WLC TURBT Number analyzed by authors:  66 participants who underwent WLC TURBT alone and 71 participants who underwent NBI + WLC TURBT Baseline characteristics of participants analyzed Comparator group, n = 66 Age: not reported Gender‐male, n (%): not reported Focality, n (%): not reported Tumour size, n (%): not reported Pathological classification, n (%): not reported Pathological grade, n (%): not reported Intervention group, n = 71 Age: not reported Gender‐male, n (%): not reported Focality, n (%): not reported Tumor size, n (%):  not reported Pathological classification, n (%): not reported Pathological grade, n (%): not reported Subsequent intravesical treatment among either group: no documentation of subsequent intravesical treatment
Interventions	Comparator arm: WLC TURBT alone Intervention arm: NBI + WLC TURBT (Olympus)
Outcomes	Surgical complication (Clavien‐Dindo) Mean time to catheter removal Absence of muscle tissue in the specimen False‐positive rate
Funding sources	Not reported
Declarations of interest	Not reported
Notes	Contact with study author Date of contact attempt: 5 October 2020 Contact status: no reply to‐date
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: Authors did not specify how random assignments were generated; however, only the abstract was available.
Allocation concealment (selection bias)	Unclear risk	Comment: The authors did not describe how, if any, concealment of allocations prior to assignment was conducted; however, only the abstract was available.
Blinding of participants and personnel (performance bias)	High risk	Comment: Personnel could not be blinded due to the nature of the intervention.
Blinding of outcome assessment (detection bias) Subjective outcomes: time to disease recurrence, minor adverse event	High risk	Comment: Authors did not specify how, if any, outcome assessment blinding was achieved. The detection of minor adverse events would be affected by a lack of blinding of outcome assessors.
Blinding of outcome assessment (detection bias) Objective outcomes: major adverse event	Low risk	Comment: The authors did not specify how, if any, blinding of outcome assessment was conducted. However, we do not expect the lack of blinding to bias the detection or reporting of major adverse events as no clinical judgement was involved.
Incomplete outcome data (attrition bias) Major adverse event	Low risk	Comment: Of the 137 participants randomized, 66 and 71 were randomized to the WLC TURBT arm and to the NBI + WLC TURBT arm, respectively. All participants were included in the analysis of adverse events. The attrition rate was less than 10% in both arms.
Incomplete outcome data (attrition bias) Minor adverse event	Low risk	Comment: Of the 137 participants randomized, 66 and 71 were randomized to the WLC TURBT arm and to the NBI + WLC TURBT arm, respectively. All participants were included in the analysis of adverse events. The attrition rate was less than 10% in both arms.
Selective reporting (reporting bias)	Unclear risk	Comment: No associated trial registration was found.
Other bias	Low risk	Comment: No additional potential sources of bias were identified.