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. 2018 Jul 25;2018(7):CD012171. doi: 10.1002/14651858.CD012171.pub2

Vanlierde 1991.

Methods Double‐blind, 2‐arm, parallel‐group, randomised controlled trial, with active comparator (no placebo) and 5 days duration of treatment
Participants Setting: multicentre, 7 continuing care wards
Sample size:
  • Number randomised: 41 participants; 71 ears

  • Number completed: 40 participants, 69 ears


Participant baseline characteristics:
  • Age: not stated (elderly)

  • Gender: not stated


Inclusion criteria: stable population of geriatric patients, must have grade 3 or 4 on a wax occlusion scale of 0 to 4 (0 being no wax)
Exclusion criteria: none mentioned
Interventions Intervention group 1 (n = unclear participants; 34 ears): almond oil, 5 drops, twice daily, for 5 days
Control group 2 (n = unclear participants; 35 ears): chlorobutanol, arachis oil and dichlorobenzene (Cerumol), 5 drops, twice daily, for 5 days
Use of additional interventions: unstated
Outcomes Primary outcomes:
  • Reduction in wax from grade 3 or 4 to grade 2


Secondary outcomes:
  • Colour and consistency of the wax


Timing of measurements:
  • After 5 days of ear drops

Funding sources No information provided
Declarations of interest No information provided
Notes One patient developed otitis externa after using chlorobutanol, arachis oil and dichlorobenzene (Cerumol) and was withdrawn from the study
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Quote: "in a randomised observer‐blind fashion"
Comment: insufficient information regarding methods used
Allocation concealment (selection bias) High risk Comment: not mentioned
Blinding of participants and personnel (performance bias) 
 All outcomes High risk Quote: "intraobserver variability was negligible due to prior self standardisation"
Blinding of outcome assessment (detection bias) 
 All outcomes Unclear risk Quote: "in a randomised observer‐blind fashion"
Incomplete outcome data (attrition bias) 
 All outcomes Low risk Comment: all participants were accounted for
Selective reporting (reporting bias) Unclear risk Comment: unclear distinction between planned methods and results reported
Other bias Low risk Comment: no further sources of bias identified