Summary of findings 3. Ventilation tubes compared to non‐surgical treatment for OME in children.

Ventilation tubes compared to non‐surgical treatment for OME in children
Patient or population: children aged 6 months to 12 years with OME Setting: outpatient Intervention: ventilation tubes Comparison: non‐surgical treatment
Outcomes	Relative effect (95% CI)	Anticipated absolute effects* (95% CI)			Certainty of the evidence (GRADE)	Comments
		With non‐surgical treatment	With ventilation tubes	Difference
Hearing ‐ mean final hearing threshold (4 months ‐ medium‐term) № of participants: 125 (1 RCT)	—	The mean threshold without ventilation tubes was 17.8 dB	11.8 dB	MD 5.98 lower (9.21 lower to 2.75 lower)	⊕⊝⊝⊝ Very low1	The evidence is very uncertain about the effect of ventilation tubes on the hearing threshold at 4 months, when compared to non‐surgical (antibiotic) treatment.
Disease‐specific quality of life	No evidence was identified for this outcome.
Presence/persistence of OME	No evidence was identified for this outcome.
Adverse event: persistent perforation (18 months ‐ long‐term) № of participants: 60 (1 RCT)	One study reported that none of 60 children who received ventilation tubes had a persistent perforation. Length of follow‐up was not reported directly, but assumed to be at the final examination at 18 months.				⊕⊕⊝⊝ Low2	Ventilation tubes may result in a low risk of persistent perforation at 18 months, when compared to non‐surgical (antibiotic) treatment.
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; MD: mean difference; OME: otitis media with effusion; RCT: randomised controlled trial
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

¹Downgraded by two levels for risk of bias, due to very serious risk of performance and detection bias. Downgraded by one level for indirectness, as some children received a different (inferior) ventilation tube. Downgraded by one level for serious imprecision, as the optimal information size was not reached (400 participants).

²Not downgraded for risk of bias, as this outcome was felt to be sufficiently objective that it would not be impacted by performance or detection bias. Downgraded by one level for indirectness, as some children received a different (inferior) ventilation tube. Downgraded by one level for serious imprecision, as this was a narrative synthesis only.