Trial design and setting
Google Trends was searched in April 2020 for Cholesteatoma and related pathological diagnosis terms. Using these data, YouTube was then searched in May 2020 for “Cholesteatoma”, “Ear Cholesteatoma”, “Cholesteatoma Removal”, “Cholesteatoma Surgery” and “Cholesteatoma Surgery Recovery”. The searches were undertaken by three different authors using Google Chrome Version 83.0.4103.61. The cache of each computer, search history and cookies of the browser were reset before each search and the authors were not signed into their Google accounts. The default reference filter was chosen as most users do not adjust filters; a Virtual Private Network (VPN) was used with IP addresses across Australia.
The search was limited to the top six English language videos for each search term as determined by YouTube’s relevance algorithm. The website results were displayed according to the default algorithm. To reproduce user search strategies, as clips were viewed and the site offered additional “up next” video suggestions, the top three suggested videos were also scored. The initial search, subsequent screening, analysis, and scoring of videos was performed independently by the three authors (NP and NJ both otologists, and HC otology Fellow).