Key messages
- From the studies included in this review, we are uncertain to what extent ventilation tubes improve hearing. Glue ear is a fluctuating condition, with high rates of spontaneous resolution and recurrence, which makes it difficult to study in a clinical trial.
- Ventilation tubes may slightly reduce the number of children who have glue ear after three to six months of follow-up. It is not clear whether they also have an effect over longer periods of time.
- Insertion of ventilation tubes can lead to a persistent hole in the eardrum (tympanic membrane perforation), ranging from 0% to 12% in the studies that we assessed.
What is OME?
Glue ear (or 'otitis media with effusion', OME) is a relatively common condition affecting young children. Fluid collects in the middle ear, which may cause hearing impairment. As a result of their poor hearing, children may be behind in their speech and may have difficulties at school.
How is OME treated?
Most of the time OME does not need any treatment and the symptoms will get better with time. In children with persistent OME, different treatments have been used, including medications or surgery (insertion of grommets, with or without adenoidectomy). Ventilation tubes (grommets) are tiny plastic or silicon tubes, which are inserted in the eardrum under general anaesthesia. The tube allows fluid to drain out of the middle ear and allows air to enter.
What did we want to find out?
We wanted to identify whether insertion of ventilation tubes was better than no treatment, or other types of treatment (such as medicines or hearing aids), for children with OME. We also wanted to see if there were any unwanted effects associated with having ventilation tubes inserted.
What did we do?
We searched for studies that compared ventilation tubes with either no treatment or a different treatment, in children with OME. We compared and summarised the study results, and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We included 19 studies with a total of 2888 participants. We considered the majority of the evidence we found to be uncertain, because of the relatively small number of children included and some issues with the conduct of the studies. The evidence from the studies done so far does not allow us to say when, and by how much, ventilation tubes will improve hearing in any specific child.
We looked for studies that compared ventilation tubes to different types of treatment, including no treatment, delayed treatment with ventilation tubes (if needed), hearing aids, antibiotics or creating a small hole in the eardrum (called 'myringotomy'). We did not find any studies that compared ventilation tubes to hearing aids, but we did find evidence for the other comparisons.
Ventilation tubes may reduce the number of children with persistent OME after three to six months of follow-up. This benefit was not seen after longer follow-up. However, many children in the 'control group' (who were planned to receive no treatment) either recovered spontaneously or received ventilation tubes during the follow-up period. This makes it hard to assess the evidence after longer follow-up.
We did not find any evidence about quality of life, so we do not know if ventilation tubes have any impact on this.
We were not able to combine the results of different studies to calculate how often an eardrum perforation may occur. However, the studies reported this side effect in between 0% and 12% of children who received ventilation tubes.
What are the limitations of the evidence?
We did not have enough information to identify whether certain groups of children would benefit from ventilation tubes (for example, children with Down syndrome or cleft palate, children with severe hearing loss or those in a certain age group). In clinical practice, different types of ventilation tubes are available, which last for different lengths of time - we did not identify any studies that specifically looked at the use of long-acting ventilation tubes, where the benefits and harms may be different. Further work needs to be done to identify which children with OME would benefit from treatment, and which children are likely to recover spontaneously.
How up-to-date is this evidence?
The evidence is up-to-date to January 2023.