The Bowel CLEANsing National Initiative: High-Volume Split-Dose Vs Low-Volume Split-Dose Polyethylene Glycol Preparations: A Randomized Controlled Trial

Development and validation of a novel scoring system based on a nomogram for predicting inadequate bowel preparation

BACKGROUND AND AIMS

Adequate bowel preparation (BP) is crucial for the diagnosis of colorectal diseases. Identifying patients at risk of inadequate BP allows for targeted interventions and improved outcomes. We aimed to develop a model for predicting inadequate BP based on preparation-related factors.

METHODS

Adult outpatients scheduled for colonoscopy between May 2022 and October 2022 were enrolled. One set (N = 913) was used to develop and internally validate the predictive model. The primary predictive model was displayed as a nomogram and then modified into a novel scoring system, which was externally validated in an independent set (N = 177). Inadequate BP was defined as a Boston Bowel Preparedness Scale (BBPS) score of less than 2 for any colonic segment. The model was evaluated by the receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA).

RESULTS

Independent factors included in the prediction model were stool frequency ≤ 5 (15 points), preparation-to-colonoscopy interval ≥ 5 h (15 points), incomplete dosage (100 points), non-split dose (90 points), unrestricted diet (88 points), no additional water intake (15 points), and last stool appearance as an opaque liquid (0-80 points). The training set exhibited the following performance metrics for identifying BP failure: area under the curve (AUC) of 0.818, accuracy (ACC) of 0.818, positive likelihood ratio (PLR) of 2.397, negative likelihood ratio (NLR) of 0.162, positive predictive value (PPV) of 0.850, and negative predictive value (NPV) of 0.723. In the internal validation set, these metrics were 0.747, 0.776, 2.099, 0.278, 0.866, and 0.538, respectively. The external validation set showed values of 0.728, 0.757, 2.10, 0.247, 0.782, and 0.704, respectively, indicating strong discriminative ability. Calibration curves demonstrated close agreement, and DCA indicated superior clinical benefits at a threshold probability of 0.73 in the training cohort and 0.75 in the validation cohort for this model.

CONCLUSIONS

This novel scoring system was developed from a prospective study and externally validated in an independent set based on 7 easily accessible variables, demonstrating robust performance in predicting inadequate BP.

Sleep Disturbances, Bowel Movement Kinetics, and Travel Interruption With Bowel Preparation: A Bowel CLEANsing National Initiative Substudy

INTRODUCTION

We investigated sleep disturbances, bowel movement (BM) kinetics, and travel experience with different bowel preparation regimens in a substudy of patients enrolled in a randomized multicenter Canadian clinical trial.

METHODS

Patients scheduled to have a colonoscopy between 7:30 am and 10:30 am (early morning) were randomized to (i) 4-L single-dose polyethylene glycol (PEG) given in the evening before, (ii) 2-L split-dose PEG (+bisacodyl 15 mg), or (iii) 4-L split-dose PEG. Patients scheduled to undergo a colonoscopy between 10:30 am and 4:30 pm (afternoon) were randomized to (iv) 2-L single-dose PEG (+bisacodyl 15 mg) in the morning, (v) 2-L split-dose PEG (+bisacodyl 15 mg), or (vi) 4-L split-dose PEG. Patients were asked to record information on BM kinetics, sleep, and travel to the endoscopy unit. Continuous and categorical variables were compared between groups using a Kruskal-Wallis test or χ 2 test, respectively. Intention-to-treat analyses were performed.

RESULTS

Overall, 641 patients were included in this substudy. Patients undergoing early morning colonoscopies reported the most awakenings in the night when assigned to 4-L single-dose day-before PEG and the highest reduction in sleep hours when assigned to 4-L split-dose PEG. There were no significant between-group differences in urgent BMs, fecal incontinence episodes, or travel interruptions. Overall, 17% of those traveling for more than an hour had to stop for a BM during travel, with no significant difference between groups.

DISCUSSION

Day-before and split-dose high-volume PEG regimens for colonoscopies scheduled before 10:30 am lead to the greatest sleep disturbance.