Factors Related to Incomplete Flexible Sigmoidoscopy Among Adult Chinese in Taiwan

BackgroundSigmoidoscopy is effective in colorectal cancer screening, but incomplete examinations may overlook colonic pathologies and delay diagnosis. This study aimed to explore risk factors for incomplete insertions of flexible sigmoidoscopy among Taiwanese.MethodsHealthy adults participating in health check-up in a tertiary medical center were invited for study. Subjects were recruited when they had fully consented and agreed to participate. Factors related to incomplete insertions of flexible sigmoidoscopy were evaluated and multivariate logistic regression was used to determine independent risk factors. A predictive model was generated by the risk factors identified.ResultsIn total, 1,252 subjects (mean age, 53.9 ± 13.1 years; age range, 21–87 years; male/female, 780/472) were enrolled, and 278 (22.2%) incomplete insertions were recorded. Multivariate analysis showed that female gender (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.56–2.73; p < 0.001), age ≥ 60 years (OR, 1.68; 95% CI, 1.26–2.23; p < 0.001), inadequate bowel preparation (OR, 1.66; 95% CI, 1.21–2.16; p = 0.001), history of constipation (OR, 2.43; 95% CI, 1.04–5.69; p = 0.042), and body mass index (BMI) < 25 kg/m2 (OR, 1.41; 95% CI, 1.05–1.89; p = 0.024) were all independent risk factors. The probability of incomplete insertion was significantly associated with the sum of the aforementioned risk factors (p < 0.001). Compared with subjects with no risk factors, the risks of incomplete insertions increased significantly among subjects bearing 1 risk factor (OR, 2.57; 95% CI, 1.47–4.49; p = 0.001), 2 risk factors (OR, 4.41; 95% CI, 2.52–7.39; p < 0.001), 3 risk factors (OR, 6.40; 95% CI, 3.56–11.52, p < 0.001) and ≥ 4 risk factors (OR, 10.00; 95% CI, 3.89–25.70, p < 0.001).ConclusionFemale sex, age ≥ 60 years, BMI < 25 kg/m2, history of constipation, and inadequate bowel preparation were independent risk factors for incomplete insertion of flexible sigmoidoscopy. Subjects with multiple risk factors may consider alternative modalities for colonic examination.