Jaffe 1978.

Methods	Double‐blind, 2‐arm, parallel‐group, randomised controlled trial, with active comparator (no placebo) and 3 applications in total (no time period)
Participants	Setting: 15 general practices, Bournemouth, UK Sample size: Number randomised: 106 participants, 106 ears Number completed: 106 participants, 106 ears Participant baseline characteristics: Age: 9 to 89 years old Gender: 46% female Inclusion criteria: all patients presenting with wax in their ears for whom a cerumenolytic would normally be prescribed Exclusion criteria: severe infection, tympanic membrane perforation
Interventions	Intervention group (n = 53 participants; 53 ears): phenazone and sodium carbonate (Otocerol) 4 drops at night, 3 applications in total Comparator group (n = 53 participants; 53 ears): arachis oil 57.3%, chlorobutanol 5%, para‐dichlorobenzene 2% (Cerumol) 5 drops at night, 3 applications in total Use of additional interventions: syringing after drops treatment if required
Outcomes	Primary outcome: Degree of wax clearance Secondary outcomes: Adverse effects Other outcomes reported by the study: Requirement for syringing Ease of syringing (where required) Timing of measurements: After 3 applications of ear drops (overnight), 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: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Patients were randomly allocated according to a previously determined scheme"
Allocation concealment (selection bias)	Unclear risk	Comment: no information provided regarding concealment
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: no information provided regarding blinding of participants
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: no information provided regarding blinding of the outcome assessor
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: the number randomised and withdrawn was not stated
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information; outcomes were not clearly defined in the methods
Other bias	High risk	Comment: overall high risk of bias for entire study, due to lack of information for all risk of bias domains