title: A question of bias.
authors.forename: J
authors.initials: J
authors.lastname: George
mesh_terms: D016022:Case-Control Studies; D002769:Cholelithiasis / Q000453:epidemiology*; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D015983:Selection Bias