Intraoperative interventions*:

• Antiseptic and/or saline washouts
• Antibiotic ear drops with or without corticosteroid
• Systemic antibiotics
• Systemic corticosteroids

Postoperative interventions*:

• Antibiotic ear drops with or without corticosteroid
• Oral antibiotics (either immediately after operation or within 6 months)
• Water precautions (actions to ensure ears are kept dry, for example, wearing ear plugs, swimming cap and headband and avoidance of swimming)

*Interventions alone or in combination

• Head-to-head comparisons between the above intraoperative intervention categories** (alone or in combination)
• Head-to-head comparisons between the above postoperative intervention categories** (alone or in combination)
• The above intraoperative interventions (alone or in combination) versus placebo
• The above postoperative interventions (alone or in combination) versus placebo
• The above intraoperative interventions (alone or in combination) versus no intervention for preventing otorrhoea
• The above postoperative interventions (alone or in combination) versus no intervention for preventing otorrhoea

**Please note, head-to-head comparisons between different interventions within each category (e.g., comparisons between different types of systemic antibiotics) were not included, only head-to-head comparisons of interventions from different categories (e.g., a systemic antibiotic versus a systemic corticosteroid)

Critical

• Otorrhoea (ear discharge) – frequency (either clinically confirmed or parent-reported)
• Adverse effects of intervention (including antimicrobial resistance)
• Acceptability

Important

• Tube blockage
• Tube extrusion
• Surgical intervention to remove VTs
• Quality of life (measured by OM8-30 questionnaire, Health Utilities Index Mark 3 (HUI3) questionnaire, Otitis Media-6 (OM-6) questionnaire, Quality of Life in Children’s Ear Problems (OMQ-14) questionnaire, Evaluation of Children’s Listening and Processing Skills (ECLiPS) questionnaire, Auditory Behaviour in Everyday Life (ABEL) questionnaire, Early Listening Function (ELF) questionnaire, Parents’ Evaluation of Aural/Oral Performance of Children (PEACH) questionnaire, EuroQol 5 Dimensions (EQ-5D) questionnaire, Infant Toddler Quality of Life Questionnaire, or Child Heath Questionnaire)