BackgroundTonsillectomy and adenoidectomy have been among the most commonly performed procedures in children for approximately 100 years. These procedures were the first for which unwarranted... Show moreBackgroundTonsillectomy and adenoidectomy have been among the most commonly performed procedures in children for approximately 100 years. These procedures were the first for which unwarranted regional variation was discovered, in 1938. Indications for these procedures have become stricter over time, which might have reduced regional practice variation.MethodsThis paper presents a historical review on practice variation in paediatric tonsillectomy and adenoidectomy rates. Data on publication year, region, level of variation, methodology and outcomes were collected.ResultsTwenty-one articles on practice variation in paediatric tonsil surgery were included, with data from 12 different countries. Significant variation was found throughout the years, although a greater than 10-fold variation was observed only in the earliest publications.ConclusionNo evidence has yet been found that better indications for tonsillectomy and adenoidectomy have reduced practice variation. International efforts are needed to reconsider why we are still unable to tackle this variation. Show less