Singer 2000.

Methods	Double‐blind, 2‐arm, parallel‐group, randomised controlled trial, with active comparator (no placebo) and 1 application for 15 minutes
Participants	Setting: single centre, university hospital emergency department, USA Sample size: Number randomised: 50 participants, 50 ears Number completed: 50 participants, 50 ears Participant baseline characteristics: Age: 1 to 81 years old (mean age 40 years) Gender: 35% female Inclusion criteria: 1 year or older, presenting to emergency department with a condition requiring visualisation of the tympanic membrane and wax present Exclusion criteria: tympanic membrane perforation, infection, uncooperative, allergies to ingredients
Interventions	Intervention group 1 (n = 27 participants; 27 ears): docusate sodium (Colace), 1 mL, once, wait 15 minutes Intervention group 2 (n = 23 participants; 23 ears): triethanolamine polypeptide (Cerumenex), 1 mL, once, wait 15 minutes Use of additional interventions: syringing if required after treatment with drops was measured and assessed
Outcomes	Primary outcomes: Proportion of patients with complete clearance of wax Secondary outcomes: Adverse effects Other outcomes reported by the study: Ease of mechanical removal Timing of measurements: After 15 minutes of ear drops, before syringing if required After syringing if required
Funding sources	No information provided
Declarations of interest	No information provided
Notes	Participants lost to follow‐up: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "assignments were generated by a computerised randomisation programme"
Allocation concealment (selection bias)	Low risk	Quote: "for each patient, the next in a series of opaque, consecutively numbered 2‐mL syringes were used. Syringes were prepared by hospital pharmacy personnel and not connected to the ED or enrolment process"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "for each patient, the next in a series of opaque, consecutively numbered 2‐mL syringes were used. Syringes were prepared by hospital pharmacy personnel and not connected to the ED or enrolment process"
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: observer bias may have occurred as the solutions were different colours
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no missing data; no withdrawals mentioned
Selective reporting (reporting bias)	Low risk	Comment: all outcomes proposed in the methods were reported in the results
Other bias	Low risk	Comment: no further sources of bias identified