Aim: To investigate the quality of YouTube videos on gallstone disease and to assess viewer response according to quality.
Methods: A YouTube search was performed on September 18, 2013, using the keywords ''gallbladder disease'', ''gallstone disease'', and ''gallstone treatment''. Three researchers assessed the source, length, number of views, number of likes, and days since upload. The upload source was categorised as physician or hospital (PH), medical website or TV channel, commercial website (CW), or civilian. A usefulness score was devised to assess video quality and to categorise the videos into ''very useful'', ''useful'', ''slightly useful'', or ''not useful''. Videos with misleading content were categorised as ''misleading''.
Results: One hundred and thirty-one videos were analysed. Seventy-four videos (56.5%) were misleading, 36 (27.5%) were slightly useful, 15 (11.5%) were useful, three (2.3%) were very useful, and three (2.3%) were not useful. The number of mean likes (1.3 ± 1.5 vs 17.2 ± 38.0, P = 0.007) and number of views (756.3 ± 701.0 vs 8910.7 ± 17094.7, P = 0.001) were both significantly lower in the very useful group compared with the misleading group. All three very useful videos were PH videos. Among the 74 misleading videos, 64 (86.5%) were uploaded by a CW. There was no correlation between usefulness and the number of views, the number of likes, or the length. The "gallstone flush" was the method advocated most frequently by misleading videos (25.7%).
Conclusion: More than half of the YouTube videos on gallstone disease are misleading. Credible videos uploaded by medical professionals and filtering by the staff of YouTube appear to be necessary.
Keywords: Cholecystitis; Gallbladder; Gallstone; Gallstone disease; YouTube.