Supplementary Material for: Association Between Examination Time and Discomfort in Unsedated Esophagogastroduodenoscopy: A Prospective Observational Study

Introduction Prolonged examination time during esophagogastroduodenoscopy is important due to its association with higher lesion detection rates. However, limited research has examined the relationship between examination time and participant discomfort. This study aimed to clarify the association between examination time and discomfort. Methods The present study is a prospective observational study conducted during esophagogastroduodenoscopy screening examinations in the endoscopy room of a screening center affiliated with a general hospital. Participants without sedation were included. The examination time was defined as the duration from the start of observation (in the laryngopharynx or esophagus) to the end of observation (in the laryngopharynx or esophagus). After the procedure, participant discomfort was assessed using the Numerical Rating Scale (NRS), an 11-point scale ranging from 0 (minimal discomfort) to 10 (maximal discomfort). The primary outcome was the relationship between examination time and participant-reported discomfort, assessed through multiple regression analysis. The dependent variable was the discomfort score on a numerical rating scale. Explanatory variables included age, sex, pethidine use, butylscopolamine use, current smoking status, alcohol intake, endoscopist, and examination time (minutes). Results A total of 3,414 participants were analyzed. The esophagogastroduodenoscopies were performed by seven endoscopists, whose experience ranged from 9 to 37 years. The rank correlation coefficient between discomfort and examination time was 0.05 (P=0.007), and the results of the multiple regression analysis showed that the regression coefficient for examination time (minutes) was 0.10 (P