“…In addition, it might be due to the fact that patient satisfaction can be affected by various factors, such as personnel's manner and skill (Ko, Zhang, Telford, & Enns, 2009), patients' information and preparedness prior to the intervention (Shepherd, Bowman, Hancock, Anglin, & Hewett, 2000;van Vliet, Grypdonck, van Zuuren, Winnubst, & Kruitwagen, 2004), and some demographic characteristics of patients like age, gender, gag reflex, and baseline anxiety (Campo et al, 1999;Trevisani et al, 2004), however, we tried to match or exclude some important factors established to have controversial effects on patient satisfaction in the current study like previous experience of EGD (Drossman et al, 1996;Rabeneck, Wristers, Souchek, & Ambriz, 2003). Although some other questionnaires have been proposed (Peña, Mardini, & Nickl, 2005), GHAA-9 questionnaire seems to be the most valid and reliable assessment tool for patient satisfaction (del Río, Baudet, Fernandez, Morales, & del Rosario Socas, 2007).…”