Radnuz 2019.

Study characteristics
Methods	A 3‐armed (Ginkgo biloba, hearing aid, Ginkgo biloba plus hearing aid), parallel‐group randomised controlled trial with 90 days duration of treatment and 90 days duration of follow‐up
Participants	Location: São Paulo, Brazil Setting: single‐centre study, outpatient clinic of the audiology centre in Rondonópolis (MT), Brazil Sample size: Number randomised: 11 in Ginkgo biloba plus hearing aid group and 11 in hearing aid group Number completed: 11 in Ginkgo biloba plus hearing aid group and 11 in hearing aid group The sample size (n = 35) was determined by the number of individuals submitted to medical consultation between July and August 2015 at an audiological centre in Rondonópolis (MT), Brazil Participant baseline characteristics: Age (mean, (SD)): group level data for age were not provided; mean age for participants in all 3 trial arms was 56.3 (16.8) years Gender (female/male, n): group level data for gender were not provided; gender distribution in all 3 trial arms was 18/15 Other characteristics: baseline tinnitus severity measured with the THI was 57.5 (SD 7.5) in the Ginkgo biloba plus hearing aids group and 52.5 (SD 5) in the hearing aids group. The 3 groups in the trial were homogeneous in the pre‐treatment period, when THI scores were compared within the confidence intervals using the ANOVA test with the application of the Tukey Average Comparison Post Test (P = 0.4708). Baseline tinnitus loudness measured with visual analogue scale (range of 0 to 10) was 6 (SD 0.6) in the Ginkgo biloba plus hearing aids group and 5.6 (SD 0.4) in the hearing aid group. Group level data for tinnitus duration were not provided. Duration of tinnitus in all 3 trial arms was 58.9 (SD 17.7) months. Baseline tinnitus quality, baseline hearing level and baseline anxiety/depression were not reported. Inclusion criteria: individuals over 18 years of age; complaint of tinnitus (uni‐ or bilateral) for at least 3 months; (single or bilateral) sensorineural or mixed hearing loss independent of degree and configuration Exclusion criteria: having used aspirin or acetylsalicylic acid in the last month, having used Ginkgo biloba in the last 3 months, on antidepressants, diagnosed with compromised middle ear (otitis or tubal dysfunction) at the time of evaluation
Interventions	Intervention group: Ginkgo biloba (EGb 761 Equitam leaf extract, patented/trademarked by Eurofarma Laboratorios S.A.), 240 mg/day plus digital Beltone hearing aid for a period of 3 months Comparator group: digital Beltone hearing aid for a period of 3 months Use of additional interventions: none
Outcomes	Primary outcome: change in tinnitus symptom severity measured using the THI and change in tinnitus loudness measured using a visual analogue scale (range of 0 to 10) at 3 months Secondary outcomes: percentage of variation of the THI score before and after treatment in relation to the tinnitus onset time at 3 months
Funding sources	Quote: "S.N.D is grateful to Anhanguera University of São Paulo(UNIAN) for providing financial support and Momenta Farmacêutica Ltd for provide the EGb 761 Equitam® Ginkgo biloba extract."
Declarations of interest	The authors declared no conflicts of interest
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The random allocation process has consisted in generating a random sequence using an Excel file for randomization and used the random allocation rule, which chooses at random one of possible balanced assignments of the given number of subjects per treatment."
Allocation concealment (selection bias)	Unclear risk	Methods of allocation concealment not reported.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "The examiners responsible for applying the questionnaires during the study were blinded to the intervention. Due to the nature of the intervention participants were not blinded."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The examiners responsible for applying the questionnaires during the study were blinded to the intervention. In addition, an employee outside the research team inserted data into the computer in separate data sheets so that the researchers can analyze data without having access to information about the allocation."
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised patients' data were analysed.
Selective reporting (reporting bias)	Low risk	All stated outcomes reported.
Other bias	Low risk	No prospective protocol available.