Classification
VO data was reviewed by ENT Surgeons (with a previously established >90% concordance) to obtain a middle ear diagnosis (Browning classification) for all children20. VO files with a visible TM perforation were then analysed by two medical students, one with a paediatric audiology background. They were trained by a senior ENT specialist on classifying perforation site and size. The students received a random sample of the same 20 VO files to classify independently. These classified files were then reviewed together with a senior ENT specialist and senior audiologist where > 90% diagnostic concordance was confirmed.
Perforations were classified as either <25%, 25-50%, 50-75% or 75-100%. The site of perforations was classified depending on the perforation size (Fig 1). Perforations deemed <25% were classified by quadrants: AS: anterosuperior, AI: anteroinferior, PS: posterosuperior, PI: posteroinferior. Perforations of size 25-50% were divided into anterior, inferior, and posterior locations. For size 50-75% they were classified into anteroinferior or posteroinferior locations. Perforations of 75-100% were classified as subtotal perforations. Where perforations didn’t completely fit the exact regions, the closest option was chosen. Where there was any ambiguity, the VO images were reviewed by all four members of the team (the senior ENT specialist, senior audiologist and two medical students) to obtain a final classification.