Fig 2.

Cumulative occurrence of failures during two year follow up in 180 children, by treatment groups (adenoidectomy, chemoprophylaxis, placebo). Failure recorded if child had two episodes of acute otitis media within two months or three episodes within six months or middle ear effusion that persisted for two months. Protocol violations regarded as drop outs. No significant differences in time to failure between groups (P=0.22 at 6 months; P=0.28 at 24 months, log rank test)