Effect of Antimicrobial Treatment on the Resolution of Middle-Ear Effusion After Acute Otitis Media.

Background. Acute otitis media (AOM) induces middle-ear effusion (MEE), which affects hearing. The effect of antimicrobial treatment on the resolution of MEE is controversial, and the factors that affect resolution are unknown. Methods. We studied the effect of antimicrobial treatment on the time to the resolution of MEE as a secondary objective in our randomized double-blind placebo-controlled trial. Children aged 6 to 35 months with stringently diagnosed AOM were allocated to receive amoxicillin-clavulanate (161 patients) or placebo (158 patients) for 7 days and closely followed for 3 months. This study was registered at ClinicalTrials.gov (identifier NCT00299455). Results. The median times to resolution of MEE were 20 days (95% confidence interval [CI], 16-24 days) and 29 days (95% CI, 26-32 days) in the amoxicillin-clavulanate and placebo groups, respectively (P=.10). The resolution of MEE was confirmed in 138 (86%) of 161 and 132 (84%) of 158 patients in the amoxicillin-clavulanate and placebo groups, respectively (P=.59). In multivariable analysis, the resolution of MEE was prolonged most significantly by at least 1 recurrence of AOM during follow-up. MEE resolved in 65 (65%) of 100 patients with a recurrence of AOM during follow-up and in 205 (94%) of 219 of those without a recurrence (P<.001) (median times to resolution, 67 vs 15 days, respectively; P<.001). Conclusions. Immediate antimicrobial treatment of AOM does not significantly affect the resolution of MEE in young children. Subsequent recurrences of AOM are a major reason for the persistence of MEE.