Patient Reported Experience in Endoscopic Ultrasound

The study will consist of several phases: 1) Tool creation: a "patient reported measure of EUS" (PREUS) questionnaire will be created based on literature review; 2) Face and Content Validity: The PREUS tool will be submitted to 7 experts in the field (physicians, nurses, psychologist, communication expert, patients' advocacy representative) for a two-round evaluation and to "expert" patients who had already undergone EUS at least once. Content Validity Index (CVI) will be calculated and questions with a CVI \< 0.70 will be excluded; 3) Questionnaire Creation: Based on the results of phase 2, a modified "PREUS" tool will be then evaluated by ranking the relevance of the identified questions in the previous phase (from 0 to 10) by 50 outpatients undergoing EUS and Cronbach's alpha will be calculated to determine reliability; 4) Ranking: tool of phase 3 will be also evaluated by 6 physicians and 13 nurses working in IRCCS Ospedale San Raffaele endoscopy Unit to measure the agreement between patients and health care professionals (HCPs) by the Spearman-Brown coefficients.