Comparative Effectiveness of Split-Dose Colonoscopy Bowel Preparation Regimens

From the patients' perspective, the most formidable part of the colonoscopy experience is the process of bowel cleansing. A poorly tolerated bowel preparation regimen often leads to incompletion of scheduled colonoscopies which in turn undermines the effectiveness of colonoscopy, increases cost, and decreases patient satisfaction. The current standard bowel preparation in the VA is of larger volume and less palatable than another commonly used bowel preparation regimen. The investigators propose to compare these two commonly used bowel preparations with respect to the overall completion rate of scheduled colonoscopies in a real-world VA practice setting. The results of the study can be immediately applied to maximize the effectiveness of colonoscopy and increase patient satisfaction in the VA.

Study Overview

• Status: Active, not recruiting
• Conditions: Colorectal Cancer
• Intervention / Treatment: Drug: Golytely; Drug: Miralax-Gatorade Prep

Detailed Description

Anticipated Impacts on Veterans Health Care: by identifying a colonoscopy bowel preparation regimen which is the most effective in real-world VA practice and can be immediately implemented on a VA-wide scale, the proposed study will maximize the effectiveness of colonoscopy in reducing colorectal cancer (CRC) risk among Veterans, increase Veteran satisfaction, and reduce VA healthcare cost. Background: CRC is a leading cause of cancer-related death among Veterans. Colonoscopy can effectively reduce CRC incidence and mortality. However, non-adherence to screening colonoscopy substantially undermines this benefit. Existing evidence indicates that a disagreeable bowel preparation is a leading barrier to completing a colonoscopy from the patients' perspective. The taste and the volume of the bowel preparation determine patient tolerability and compliance to the preparation instructions, which in turn affects the incompletion (e.g., cancellation/no-show/reschedule) rate of scheduled colonoscopies as well as the effectiveness of the completed colonoscopies and patient satisfaction. The two most commonly used preparations currently in the US are the split-dose 4L polyethylene glycol (PEG) and the split-dose 2L MiraLAX/Gatorade preparations. While a high-volume regimen may in theory be more effective than a lower volume one, it may be associated with lower tolerability and adherence in real-world practice. Three small trials have compared these two preparations. However, data from these explanatory trials cannot inform policy decisions because they were conducted under artificial conditions, restricted among narrow patient populations, and most importantly not designed to capture the full impact of bowel preparation on the completion rate or effectiveness of colonoscopy. To address this critical knowledge gap, the investigators are proposing a pragmatic trial to determine the optimal split-dose bowel preparation in the general Veteran population. Objectives: to compare the real-world effectiveness of the two most commonly used split-dose colonoscopy bowel preparation regimens in the US (i.e., 4L PEG and 2L MiraLAX/Gatorade) with respect to the completion rate of scheduled colonoscopies, adenoma detection rate and secondarily preparation quality, cancellation/no-show rate and patient-oriented outcomes (e.g., willingness to repeat the preparation).

• Study Type: Interventional
• Enrollment (Actual): 2261
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Yu-Xiao Yang, MD MSCE; Phone Number: (215) 823-5800; Email: YuXiao.Yang@va.gov

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104-4551
      • Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• > 18 years of age, and
• being scheduled for outpatient elective screening, surveillance or diagnostic colonoscopies, and
• the provider ordering the colonoscopy giving permission to enroll the patient.

Exclusion Criteria:

• Patients who are <18 years
• undergoing inpatient colonoscopy
• those with contra-indications to receiving the standard 4L PEG-ELS colonoscopy bowel preparation (e.g., allergy to PEG) will be excluded

• Those with a preference for a specific bowel preparation will be excluded.

  • The investigators are excluding inpatient colonoscopies because they account for a very small fraction of the total colonoscopies performed.
  • Also, inpatient colonoscopies are often performed for urgent reasons such that rapid bowel preparation procedures are followed.
• In addition, because the objective of inpatient colonoscopy is often not to look for small polyps, the threshold for "adequate" bowel preparation quality might be different from that for outpatient procedures.
• In addition, for patients undergoing more than 1 colonoscopy during the study period, only their first colonoscopy will be included in the primary analysis.
• Patients who are undergoing a repeat colonoscopy for to a recent inadequate colonoscopy examination with poor bowel preparation will be excluded.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Golytely; 4-L split-dose Golytely bowel prep	Drug: Golytely; 4-L split dose Golytely is the current standard prep at the VA
Experimental: Miralax-Gatorade prep; 2-L split-dose Miralax-Gatorade bowel prep	Drug: Miralax-Gatorade Prep; 2-L split-dose Miralax-Gatorade bowel prep for colonoscopy

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
colonoscopy completion rate	The completion rate of scheduled colonoscopy will be defined as the proportion of patients who show up for their scheduled colonoscopy and have endoscopist-rated "adequate" bowel preparation quality, among those scheduled for a colonoscopy.	This outcome is determined within 1 month after colonoscopy
Population level adenoma detection rate (ADR)	the ADR is estimated as the proportion of patients with at least one adenoma detected among all patients scheduled for colonoscopy.	within 1 month of colonoscopy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
cancellation or no-show in each bowel prep arm	The proportion of patients who cancel or no-show in each group.	within 1 month after colonoscopy
Adequate bowel prep quality	this is a binary indictor based on endoscopist rating of excellent or good quality bowel preparation	within 1 month after the colonoscopy

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
patients with inadequate bowel preparation who are recommended to have earlier-than-usual follow-up colonoscopy	patients with inadequate bowel preparation who are recommended to have earlier-than-usual follow-up colonoscopy	within 1 month after colonoscopy
hyponatremia	Hyponatremia	within 6 months after colonoscopy
renal failure	renal failure documented in CPRS	within 6 months of colonoscopy

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Investigators: Principal Investigator: Yu-Xiao Yang, MD MSCE, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA

Publications and helpful links

General Publications

• Patel D, Yang YX, Trivedi C, Kavani H, Xie D, Medvedeva E, Lewis J, Khan N. Incidence, Duration, and Management of Anemia: A Nationwide Comparison Between IBD and Non-IBD Populations. Inflamm Bowel Dis. 2020 May 12;26(6):934-940. doi: 10.1093/ibd/izz206.

Study record dates

Study Major Dates

• Study Start (Actual): December 13, 2018
• Primary Completion (Actual): December 30, 2023
• Study Completion (Estimated): June 30, 2024

Study Registration Dates

• First Submitted: September 26, 2017
• First Submitted That Met QC Criteria: September 29, 2017
• First Posted (Actual): October 2, 2017

Study Record Updates

• Last Update Posted (Actual): January 5, 2024
• Last Update Submitted That Met QC Criteria: January 3, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: colorectal cancer; colonoscopy; pragmatic trial; bowel preparation regimen
• Additional Relevant MeSH Terms: Digestive System Diseases; Neoplasms; Neoplasms by Site; Gastrointestinal Neoplasms; Digestive System Neoplasms; Gastrointestinal Diseases; Colonic Diseases; Intestinal Diseases; Intestinal Neoplasms; Rectal Diseases; Colorectal Neoplasms; Gastrointestinal Agents; Laxatives; Polyethylene glycol 3350
• Other Study ID Numbers: IIR 15-346

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No