Supplementary Material for: Exploring the perceived risk of complications in endoscopic screening procedures

Background&Aims: Endoscopy holds a pivotal role in colorectal (CRC) and gastric cancer screening, and adherence rates might be impacted by the patient's risk perception, encompassing concerns about complications during endoscopic screening procedures. This study aimed to evaluate how individuals perceive the risk of complications associated with undergoing a screening colonoscopy and upper gastrointestinal endoscopy (UGIE).Methods: Cross-sectional study enrolling individuals eligible for CRC screening in northern Portugal, where a populational fecal occult blood test program is implemented. The validated PERCEPT-PREVENT tool was applied through telephonic interviews in 2 groups: a) never-screened, and b) already submitted to endoscopic screening.Results: Among the 217 included healthy participants, 61% (n=133) and 83% (n=181) were unaware of any possible complications from colonoscopy and UGIE, respectively. Never-screened individuals less frequently reported a high complication risk perception (colonoscopy 19% vs 45%; p<0.001; UGIE 14% vs 41%; p<0.001). A lower risk perception for UGIE complications was associated with a higher willingness to undergo UGIE combined with a screening colonoscopy (OR 2.30, 95%CI 1.42-3.70). Participants who underwent combined screening reported less frequently a high complication risk perception (colonoscopy 27% vs 61%; p<0.001; UGIE 28% vs 54%; p=0.006) and scored higher for complication awareness (colonoscopy: 14±5 vs 11±4; p<0.001; UGIE: 11±4 vs 9±3; p<0.001) compared to those who had only undergone colonoscopy.Discussion: Enhancing risk perception and knowledge of complications associated with endoscopic screening procedures offers an opportunity to increase adherence rates.