Association Between Longer Cecal Intubation Time and Detection and Miss Rate of Colorectal Neoplasms

<b>Background/Aims:</b> A longer cecal intubation time (CIT) occurs during colonoscopy under difficult insertion conditions, which may hinder meticulous mucosal observation. However, whether a longer CIT has detrimental effects on the detection of adenomas remains unclear. We evaluated the effects of CIT on the detection and miss rates of colorectal neoplasms in asymptomatic participants. <b>Methods:</b> Healthy examinees who underwent colonoscopy between March and July 2011, August 2015, and December 2016 were retrospectively enrolled. The primary outcome was the adenoma detection rate (ADR) across CIT quartiles, while the secondary outcomes included the mean number of adenomas, advanced ADR (AADR), clinically significant serrated lesion (CSSP) detection, adenoma miss rate (AMR), miss rate of CSSPs and any colorectal neoplasms, and the mean number of missed colorectal neoplasms in relation to CIT. <b>Results:</b> Overall, 12,402 participants were classified into quartiles according to the CIT. The longer the CIT, the lower the ADR (<i>p</i> < 0.001), AADR (<i>p</i> = 0.004), and mean number of adenomas (<i>p</i> < 0.001). The CSSP detection rate was not associated with CIT. On follow-up colonoscopy, AMR showed marginal increase with longer CIT (<i>p</i> = 0.065). The missed rates of CSSPs (<i>p</i> = 0.002) and colorectal neoplasms (<i>p</i> = 0.001) also increased with longer CIT. In the multivariate analysis, CIT was significantly associated with ADR, AADR, and AMR. <b>Conclusions:</b> Longer CIT was associated with lower ADR and higher AMR. Meticulous inspection is important for high-quality colonoscopy, particularly in patients requiring a longer CIT.