Single-use versus reusable endoscopes in gastroenterology: Systematic review of full and partial economic evaluations - Mandana Zanganeh; Yufei Jiang; Norman Waugh; Anna Brown; Yen-Fu Chen; Ramesh P. Arasaradnam; Lazaros Andronis; on behalf of the "SUMU Endo" project group (Endoscopy International Open)