Yun Xu, Shan Ou, Xiu Yuan, Jie Yao, Tianwen Yang

Department of Gastroenterology, The First Hospital Affiliated of Chongqing Medical and Pharmaceutical College, Chongqing, 400060, People’s Republic of China

Correspondence: Tianwen Yang, Email yangushuo519hhn@163.com

Objective: To establish a prediction model for the risk of inadequate bowel preparation for colonoscopy in the elderly, and to validate the model to test its prediction effect.
Methods: A total 927 patients who underwent colonoscopy in the First Affiliated Hospital to Chongqing Medical and Pharmaceutical College from January to December 2023 were selected as the modeling group, and were divided into the success group (839 patients) and failure group (88 patients) according to whether or not inadequate bowel preparation occurred, and then a logistic regression prediction model was established and transformed into a risk scoring system. The area under the ROC curve and the Hosmer-Lemeshow test were used for model differentiation and calibration, respectively, and the 10-fold cross-validation method was used for internal validation of the model. A total of 548 patients who underwent colonoscopy in our hospital from January to June 2024 were selected for external validation of the model.
Results: Logistic regression analysis showed that age ≥ 65 years, diabetes mellitus, exercise habits, Bristol stool characterization scale, frailty, and ambulatory functional status were independent factors influencing the inadequate bowel preparation for colonoscopy in the elderly. The area under the ROC curve for the modeling group was 0.806, and the Hosmer-Lemeshow test showed p=0.870. The area under the ROC curve of the validation group was (0.785± 0.090). The area under the ROC curve of the validation group was 0.824, and the Hosmer-Lemeshow test showed P=0.907, with a sensitivity of 73.13%, a specificity of 80.70%, and a Jordon’s index of 0.538.
Conclusion: The predictive model of the risk of inadequate bowel preparation for colonoscopy in elderly people can predict the risk of inadequate bowel preparation in elderly people, and can be used as a tool for clinical caregivers to screen the high-risk group of inadequate bowel preparation in the elderly.

Keywords: elderly, colonoscopy, inadequate bowel preparation, predictive modeling, risk score