Martyn Parker, first author of more than 15 Cochrane reviews, who taught me how to write papers and who created my interest in writing Cochrane reviews.
Dimitrinka Nikolova, Cochrane Hepato‐Biliary Review Group Co‐ordinator, who provided guidance and made corrections.
Christian Gluud, Cochrane Hepato‐Biliary Group, who provided guidance.
Sarah Louise Klingenberg, Cochrane Hepato‐Biliary Group, who provided help with searching the databases.
Yan Gong, Cochrane Hepato‐Biliary Group, who provided statistical advice.
Abe Fingerhut, Cochrane Hepato‐Biliary Group Editor, who provided advice.
Pepe Mullerat, Registrar Northampton General Hospital, who helped with a Spanish translation.
Stoke Mandeville Hospital library, which obtained the full text articles for many of the references cited in this review.