A cost-benefit analysis of the post-operative use of antibiotic ear drops following grommet insertion.

A prospective randomized controlled study was carried out to investigate the effect of prophylactic antibiotic ear drops used for five days after bilateral grommet insertion. The average improvement in the hearing threshold was significantly better in ears in which there was an effusion (16 dB) compared with no effusion (9 dB). The drops had no significant effect upon grommet function at three months measured by blockage rates, extrusion rates or improvement in pure tone audiometry whether or not there was an effusion. The drops were not therefore cost-effective.