Given the heterogeneous nature of otolaryngology interventions, each was allocated to one of the following:

Interventions for hearing (bone-anchored hearing aid, cochlear implant, middle ear implant, stapes surgery).

Interventions for benign tumours (vestibular schwannoma).

Interventions for nasal function (septoplasty for nasal obstruction and endoscopic sinus surgery for chronic sinusitis).

Interventions for epiphora (dacryocystorhinostomy).

Interventions for cosmesis (rhinoplasty and auricular reconstruction/otoplasty).

Interventions for chronic tonsillitis (tonsillectomy).

Interventions for snoring.

Interventions for dystonia (botulinum toxin).