Ventilation tubes (grommets) for otitis media with effusion (OME) in children

Otitis media with effusion (OME) is an accumulation of fluid in the middle ear cavity, common amongst young children. It may cause hearing loss which, when persistent, may lead to developmental delay, social difficulty and poor quality of life. Management includes watchful waiting, autoinflation, medical and surgical treatment. Insertion of ventilation tubes has often been used as the preferred treatment.

To evaluate the effects (benefits and harms) of ventilation tubes (grommets) for OME in children.

We searched the Cochrane ENT Register, CENTRAL, Ovid MEDLINE, Ovid Embase, Web of Science, ClinicalTrials.gov, ICTRP and additional sources for published and unpublished trials on 20 January 2023.

We included randomised controlled trials (RCTs) and quasi-RCTs in children (6 months to 12 years) with OME for ≥ 3 months. We included studies that compared ventilation tube (VT) insertion with five comparators: no treatment, watchful waiting (ventilation tubes inserted later, if required), myringotomy, hearing aids and other non-surgical treatments.

We used standard Cochrane methods. Our primary outcomes were determined following a multi-stakeholder prioritisation exercise and were: 1) hearing; 2) OME-specific quality of life; 3) persistent tympanic membrane perforation (as a severe adverse effect of the surgery). Secondary outcomes were: 1) persistence of OME; 2) other adverse effects (including tympanosclerosis, VT blockage and pain); 3) receptive language skills; 4) speech development; 5) cognitive development; 6) psychosocial skills; 7) listening skills; 8) generic health-related quality of life; 9) parental stress; 10) vestibular function; 11) episodes of acute otitis media. We used GRADE to assess the certainty of evidence for key outcomes. Although we included all measures of hearing assessment, the proportion of children who returned to normal hearing was our preferred method, due to challenges in interpreting the results of mean hearing thresholds.

We included 19 RCTs (2888 children). We considered most of the evidence to be very uncertain, due to wide confidence intervals for the effect estimates, few participants, and a risk of performance and detection bias. Here we report our key outcomes at the longest reported follow-up. There were some limitations to the evidence. No studies investigated the comparison of ventilation tubes versus hearing aids. We did not identify any data on disease-specific quality of life; however, many studies were conducted before the development of specific tools to assess this in otitis media. Short-acting ventilation tubes were used in most studies and thus specific data on the use of long-acting VTs is limited. Finally, we did not identify specific data on the effects of VTs in children at increased risk of OME (e.g. with craniofacial syndromes). Ventilation tubes versus no treatment (four studies) The odds ratio (OR) for a return to normal hearing after 12 months was 1.13 with VTs (95% confidence interval (CI) 0.46 to 2.74; 54% versus 51%; 1 study, 72 participants; very low-certainty evidence). At six months, VTs may lead to a large reduction in persistent OME (risk ratio (RR) 0.30, 95% CI 0.14 to 0.65; 20.4% versus 68.0%; 1 study, 54 participants; low-certainty evidence). The evidence is very uncertain about the chance of persistent tympanic membrane perforation with VTs at 12 months (OR 0.85, 95% CI 0.38 to 1.91; 8.3% versus 9.7%; 1 RCT, 144 participants). Early ventilation tubes versus watchful waiting (six studies) There was little to no difference in the proportion of children whose hearing returned to normal after 8 to 10 years (i.e. by the age of 9 to 13 years) (RR for VTs 0.98, 95% CI 0.94 to 1.03; 93% versus 95%; 1 study, 391 participants; very low-certainty evidence). VTs may also result in little to no difference in the risk of persistent OME after 18 months to 6 years (RR 1.21, 95% CI 0.84 to 1.74; 15% versus 12%; 3 studies, 584 participants; very low-certainty evidence). We were unable to pool data on persistent perforation. One study showed that VTs may increase the risk of perforation after a follow-up duration of 3.75 years (RR 3.65, 95% CI 0.41 to 32.38; 1 study, 391 participants; very low-certainty evidence) but the actual number of children who develop persistent perforation may be low, as demonstrated by another study (1.26%; 1 study, 635 ears; very low-certainty evidence). Ventilation tubes versus non-surgical treatment (one study) One study compared VTs to six months of antibiotics (sulphisoxazole). No data were available on return to normal hearing, but final hearing thresholds were reported. At four months, the mean difference was -5.98 dB HL lower (better) for those receiving VTs, but the evidence is very uncertain (95% CI -9.21 to -2.75; 1 study, 125 participants; very low-certainty evidence). No evidence was identified regarding persistent OME. VTs may result in a low risk of persistent perforation at 18 months of follow-up (no events reported; narrative synthesis of 1 study, 60 participants; low-certainty evidence). Ventilation tubes versus myringotomy (nine studies) We are uncertain whether VTs may slightly increase the likelihood of returning to normal hearing at 6 to 12 months, since the confidence intervals were wide and included the possibility of no effect (RR 1.22, 95% CI 0.59 to 2.53; 74% versus 64%; 2 studies, 132 participants; very low-certainty evidence). After six months, persistent OME may be reduced for those who receive VTs compared to laser myringotomy, but the evidence is very uncertain (OR 0.27, 95% CI 0.19 to 0.38; 1 study, 272 participants; very low-certainty evidence). At six months, the risk of persistent perforation is probably similar with the use of VTs or laser myringotomy (narrative synthesis of 6 studies, 581 participants; moderate-certainty evidence).

There may be small short- and medium-term improvements in hearing and persistence of OME with VTs, but it is unclear whether these persist after longer follow-up. The RCTs included do not allow us to say when (or how much) VTs improve hearing in any specific child. However, interpretation of the evidence is difficult: many children in the control groups recover spontaneously or receive VTs during follow-up, VTs may block or extrude, and OME may recur. The limited evidence in this review also affects the generalisability/applicability of our findings to situations involving children with underlying conditions (e.g. craniofacial syndromes) or the use of long-acting tubes. Consequently, RCTs may not be the best way to determine whether an intervention is likely to be effective in any individual child. Instead, we must better understand the different OME phenotypes to target interventions to children who will benefit most, and avoid over-treating when spontaneous resolution is likely.