title: Response to Kanna and Hassan.
authors.forename: Frederick K
authors.initials: FK
authors.lastname: Shieh
authors.forename: Uzma D
authors.initials: UD
authors.lastname: Siddiqui
authors.forename: Harry R
authors.initials: HR
authors.lastname: Aslanian
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D009726:Nurses / Q000706:statistics & numerical data*; D015588:Observer Variation