A = adenoidectomy; T= tonsillectomy; A+T= adenotonsillectomy; ORCHL = OME-related conductive hearing losses; OME = otitis media with effusion; RAOM = recurrent acute otitis media; PTA = pure tone audiometry

Supplementary Material Captions

Supplementary Figure 1: PRISMA style flow diagram of studies selection through systematic review

Supplementary Table 1: Search strategy ad results for all consulted databases

Supplementary Table 2: List of articles excluded during the full-text evaluation