Effect of antimicrobial treatment of acute otitis media on the daily disappearance of middle ear effusion: a placebo-controlled trial.

IMPORTANCE Antimicrobial treatment reduces the symptoms of acute otitis media (AOM). The effect of antimicrobial treatment on the duration of middle ear effusion (MEE) and concomitant hearing impairment is not known. OBJECTIVE To determine whether the antimicrobial treatment of AOM reduces the duration of MEE. DESIGN, SETTING, AND PARTICIPANTS This randomized, double-blind, placebo-controlled trial involved a total of 84 children with AOM between 6 months and 15 years of age. Participants were recruited from September 14, 1999, to January 4, 2000; October 10, 2005, to December 16, 2005; and September 22, 2009, to June 4, 2012, from among children attending an AOM prevention trial and children visiting local outpatient clinics in Oulu, Finland. INTERVENTIONS Children were randomly allocated to receive either 40 mg/kg of amoxicillin-clavulanate or a placebo mixture per day for 7 days. MAIN OUTCOMES AND MEASURES The primary outcome measure was the time to the disappearance of MEE as defined by a normal tympanogram finding (A curve) from both ears on 2 consecutive measurement days. Parents performed daily tympanometry at home. The study physician performed tympanometry and otoscopy at study entry, after 3 and 7 days, and then weekly until both ears were healthy. The main secondary outcome measures were the time to normal otoscopy findings and the proportion of children without persistent MEE at 14 days and 2 months. RESULTS Middle ear effusion disappeared 2.0 weeks (13.7 days) earlier (P = .02) in the antimicrobial group (mean time, 2.7 weeks; 95% CI, 1.7-3.7) than in the placebo group (4.7 weeks; 95% CI, 3.6-5.7). Normal otoscopy findings were observed 1.4 weeks sooner in the antimicrobial group than in the placebo group (P = .02). On day 14, 69% of children in the antimicrobial group and 38% in the placebo group had normal tympanometry findings (number needed to treat, 3.2; 95% CI, 2.0-10.5). On day 60, 2 children (5%) in the antimicrobial group and 10 children (24%) in the placebo group had persistent MEE (P = .01). CONCLUSIONS AND RELEVANCE Antimicrobial treatment effectively reduced the duration of MEE and possible concomitant hearing impairment in children with AOM. Antimicrobial treatment also reduced the risk for persistent MEE. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01244581.