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. 2022 Apr 8;2022(4):CD014887. doi: 10.1002/14651858.CD014887.pub2

Kim 2018.

Study characteristics
Methods Study design: randomized controlled trial
Study grouping: parallel group
Participants Inclusion criteria: people who underwent TURBT for suspicion of a bladder tumor discovered by use of cystoscopy or another imaging study
Exclusion criteria: people with muscle‐invasive tumors, those undergoing radical cystectomy, those receiving chemotherapy or radiotherapy, those with nonurothelial carcinoma, those who were not histologically diagnosed with cancer, those lost to follow‐up, and those who died for other reasons
Number randomized: 198 (97 participants to undergo WLC TURBT and 101 participants to undergo NBI + WLC TURBT)
Number analyzed by authors: 35 participants who underwent WLC TURBT and 39 participants who underwent NBI + WLC TURBT, and had follow‐up at 12 months
Baseline characteristics of randomized participants who were not found to have muscle‐invasive tumor or nonurothelial carcinoma, those who did not undergo radical cystectomy during the study period, and those who did not receive chemotherapy (n = 67 comparison arm, n = 85 intervention arm)
Comparator group, n = 67 participants

  • Age, mean (SD): 66.96 (11.51)

  • Gender‐male, n (%): 54 (80.6)

  • Focality, n (%): not reported

  • Tumour size, n (%)

    • < 1 cm: 40 (59.7)

    • 1 to 3 cm: 19 (28.4)

    • > 3 cm: 8 (11.9)

  • Pathological classification, n (%)

    • pT0: 12 (17.9)

    • CIS: 2 (3.0)

    • pTa: 37 (55.2)

    • pT1: 16 (23.9)

  • Pathological grade, n (%)

    • No tumor or carcinoma in situ: 14 (20.9)

    • Low: 24 (35.8)

    • High: 29 (43.3)


Intervention group, n = 85 participants

  • Age, mean (SD): 65.54 (12.01)

  • Gender‐male, n (%): 62 (72.9)

  • Focality, n (%): not reported

  • Tumour size, n (%)

    • < 1 cm: 42 (49.4)

    • 1 to 3 cm: 35 (41.4)

    • > 3 cm: 8 (9.4)

  • Pathological classification, n (%)

    • pT0: 13 (15.3)

    • CIS: 3 (3.5)

    • pTa: 52 (61.2)

    • pT1: 17 (20.0)

  • Pathological grade, n (%)

    • No tumor or carcinoma in situ: 17 (20.0)

    • Low: 33 (38.8)

    • High: 35 (41.2)


Subsequent intravesical treatment among either group: no documentation of subsequent intravesical treatment
Interventions Comparator group: WLC TURBT
Intervention group: NBI + WLC TURBT
Outcomes Number of tumors identified
Disease recurrence at 12 months
Funding sources Not reported
Declarations of interest The authors reported having no conflict of interest to declare.
Notes Contact with study author
Date of contact attempt: 13 January 2021
Contact status: no reply to‐date
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote: "The participants were randomly divided into the NBI (experimental) and WLC (control) groups. Randomization was conducted by means of a computer‐generated random sequence of numbers"
Comment: Randomization was performed by a computer‐generated random sequence.
Allocation concealment (selection bias) High risk Quote: "Before procedures, participants eligible for the study were contacted by medical staff and provided with verbal and written information."
Comment: There was no mention of allocation concealment methods.
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 disease recurrence would be affected by a lack of blinding of outcome assessors.
Incomplete outcome data (attrition bias)
Time to disease recurrence High risk Comment: Of the 198 participants enrolled, 97 and 101 were randomized to the WLC TURBT arm and the NBI + WLC TURBT arm, respectively. Only 35 participants of the WLC TURBT arm and 39 participants of the NBI + WLC TURBT arm were included for analysis of disease recurrence at 12 months (36% and 39%, respectively). The attrition rate was greater than 20% in both arms. 
Selective reporting (reporting bias) Unclear risk Comment: This study was registered in the Korea University Anam Hospital clinical trial center (approval number: MD13008). However, the registration protocol was not available for comparison.
Other bias Low risk Comment: No additional sources of potential bias were identified.