BackgroundOtitis media with effusion (OME) is a very common problem in primary care, but one that lacks an evidence-based non-surgical treatment.ObjectiveTo determine the clinical effectiveness of nasal balloon autoinflation for the treatment of OME in children.DesignA pragmatic, two-arm, open randomised controlled trial.SettingForty-three general practices from 17 UK primary care trusts recruited between January 2012 and February 2013.ParticipantsSchool children aged 4–11 years with a history of OME symptoms or related concerns in the previous 3 months, and a type B tympanogram, diagnostic of a middle ear effusion, in one or both ears.InterventionThree hundred and twenty children were randomised, 160 to each group, using independent web-based computer-generated randomisation (with minimisation based on age, sex and baseline severity of OME) to either nasal balloon autoinflation performed three times per day for 1–3 months plus usual care, or usual care alone.Main outcome measuresThe proportion of children demonstrating clearance of middle ear fluid in at least one ear (with normal tympanograms) at 1 and 3 months, assessed blind to treatment. An ear-related measure of quality of life (QoL) [a 14-point questionnaire on the impact of OME (OMQ-14)], weekly diary recorded symptoms, compliance and adverse events were all secondary outcomes.ResultsAt 1 month, the proportion of children with normal tympanograms was 47.3% (62/131) in those allocated to autoinflation and 35.6% (47/132) in those receiving usual care [adjusted relative risk (RR) 1.36, 95% confidence interval (CI) 0.99 to 1.88]. At 3 months, the proportions were 49.6% (62/125) and 38.3% (46/120), respectively (adjusted RR 1.37, 95% CI 1.03 to 1.83; number needed to treat = 9). The change in OMQ-14 also favoured the intervention arm (adjusted global score difference –0.42;p = 0.001). Reported compliance was good: 89% in the first month and 80% in months 2 and 3. Adverse events included otalgia in 4% of treated children compared with 1% in the control group. Minor nosebleeds (14% vs. 15%) and respiratory tract infections (18% vs. 13%) were noted.ConclusionWe found the use of autoinflation in young children with OME to be feasible in primary care and effective in both clearing effusions and improving child and parent ear-related QoL and symptoms. This method has scope to be used more widely. Further research is needed for very young children, and to inform prudent use in different health settings.Trial registrationCurrent Controlled Trials ISRCTN55208702.FundingThis project was funded by the National institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full inHealth Technology Assessment, Vol. 19, No. 72. See the NIHR Journals Library website for further project information.