Ten studies (n=2,347) met the inclusion criteria. Individual patient data could not be retrieved for 3 studies (n=1,116). Seven studies (n=1,231) were included in the review. The final follow-up ranged from 1 to 10 years.
Time spent with effusion.
The mean time spent with effusion was statistically significantly lower in children with ventilation tubes (19.7 weeks, 95% CI: 17.6, 21.9) than children in the watchful-waiting group (37 weeks, 95% CI: 34.9, 39.1) at the 12-month follow-up (557 children, P<0.001).
Hearing level.
The mean hearing level was statistically significantly better in children with ventilation tubes (26.6 dB HL, SE 1.0) than children in the watchful-waiting group (31.1 dB HL, SE 1.0) at the 6-month follow-up (574 children, P=0.001). However, there were no differences at 12 or 18 months' follow-up. Predictors of poor hearing at 6, 12 and 18 months included baseline hearing loss, attendance in day-care, age and season, and being breast fed. The fixed-effect regression analysis showed ventilation tubes were only differentially effective in children attending day-care, where the hearing level was 7 dB HL better in children with ventilation tubes.
In studies where one ear was treated and the contralateral ear was used as the comparator (160 children), hearing improved by 10 dB HL more in ears with ventilation tubes than in ears not treated at 6 months, and 7 dB HL at 12 months, when the hearing loss at baseline was 25 dB HL or more. When the hearing loss was less than 25 dB HL, the improvement in ears with ventilation tubes was 4 dB HL greater than control ears at the 6-month follow-up, and 3 dB HL at 12 months.
Language development.
There was no statistically significant difference in language development between children with ventilation tubes and children in the watchful-waiting group at 6/9 or 12/18 months' follow-up (381 children).
Children with more than one risk factor appeared to benefit slightly more from treatment with ventilation tubes than children with one risk factor.