Colorectal Cancer
Conditions
Keywords
colonoscopy, colorectal cancer, bowel preparation regimen, pragmatic trial
Brief summary
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.
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).
Interventions
2-L split-dose Miralax-Gatorade bowel prep for colonoscopy
4-L split dose Golytely is the current standard prep at the VA
Sponsors
Study design
Intervention model description
Parallel groups
Eligibility
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Colonoscopy Completion Rate | This outcome is determined within 1 month after colonoscopy | 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. |
| Population Level Adenoma Detection Rate (ADR) | within 1 month of colonoscopy | the ADR is estimated as the proportion of patients with at least one adenoma detected among all patients scheduled for colonoscopy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cancellation or No-show in Each Bowel Prep Arm | within 1 month after colonoscopy | The proportion of patients who cancel or no-show in each group. |
| Adequate Bowel Prep Quality | within 1 month after the colonoscopy | this is a binary indictor based on endoscopist rating of excellent or good quality bowel preparation |
Other
| Measure | Time frame | Description |
|---|---|---|
| Hyponatremia | within 6 months after colonoscopy | Hyponatremia |
| Renal Failure | within 6 months of colonoscopy | renal failure documented in CPRS |
| Patients With Inadequate Bowel Preparation Who Are Recommended to Have Earlier-than-usual Follow-up Colonoscopy | within 1 month after colonoscopy | patients with inadequate bowel preparation who are recommended to have earlier-than-usual follow-up colonoscopy |
Countries
United States
Participant flow
Recruitment details
Participants were recruited based on referral from the primary care providers ordering colonoscopy at the Corporal Michael J. Crescenz Department of Veterans Affairs Medical Center. The first participant was enrolled on December 13, 2018, and the last participant was enrolled on January 27, 2023.
Pre-assignment details
Of the 3869 patients assessed for eligibility, 2239 met the eligibility criteria and were randomized.
Participants by arm
| Arm | Count |
|---|---|
| Golytely 4-L split-dose Golytely bowel prep
Golytely: 4-L split dose Golytely is the current standard prep at the VA | 1,139 |
| Miralax-Gatorade Prep 2-L split-dose Miralax-Gatorade bowel prep
Miralax-Gatorade Prep: 2-L split-dose Miralax-Gatorade bowel prep for colonoscopy | 1,100 |
| Total | 2,239 |
Baseline characteristics
| Characteristic | Miralax-Gatorade Prep | Total | Golytely |
|---|---|---|---|
| Age, Continuous | 62.6 years STANDARD_DEVIATION 9.5 | 62.6 years STANDARD_DEVIATION 7.2 | 62.6 years STANDARD_DEVIATION 9.7 |
| Alcohol use disorder | 116 Participants | 224 Participants | 108 Participants |
| Body mass index group <18.5 kg/m^2 | 9 Participants | 19 Participants | 10 Participants |
| Body mass index group 18.5 to 24.9 kg/m^2 | 175 Participants | 373 Participants | 198 Participants |
| Body mass index group 25 to 29.9 kg/m^2 | 368 Participants | 763 Participants | 395 Participants |
| Body mass index group 30 or more kg/m^2 | 543 Participants | 1070 Participants | 527 Participants |
| Body mass index group Missing | 5 Participants | 14 Participants | 9 Participants |
| Colonoscopy indications Diagnostic | 152 Participants | 323 Participants | 171 Participants |
| Colonoscopy indications Screening | 508 Participants | 989 Participants | 481 Participants |
| Colonoscopy indications Surveillance | 440 Participants | 927 Participants | 487 Participants |
| Constipation or narcotic use | 22 Participants | 41 Participants | 19 Participants |
| Diabetes mellitus | 329 Participants | 663 Participants | 334 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 48 Participants | 84 Participants | 36 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 1020 Participants | 2094 Participants | 1074 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 32 Participants | 61 Participants | 29 Participants |
| Mental health disorders | 398 Participants | 769 Participants | 371 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 18 Participants | 28 Participants | 10 Participants |
| Race (NIH/OMB) Black or African American | 397 Participants | 804 Participants | 407 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 18 Participants | 27 Participants | 9 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 36 Participants | 79 Participants | 43 Participants |
| Race (NIH/OMB) White | 631 Participants | 1301 Participants | 670 Participants |
| Sex: Female, Male Female | 113 Participants | 220 Participants | 107 Participants |
| Sex: Female, Male Male | 987 Participants | 2019 Participants | 1032 Participants |
| Smoking status Current smoker | 306 Participants | 633 Participants | 327 Participants |
| Smoking status Former smoker | 430 Participants | 885 Participants | 455 Participants |
| Smoking status Missing | 25 Participants | 35 Participants | 10 Participants |
| Smoking status Never smoker | 339 Participants | 686 Participants | 347 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 7 / 1,139 | 4 / 1,100 |
| other Total, other adverse events | 0 / 1,139 | 0 / 1,100 |
| serious Total, serious adverse events | 6 / 1,139 | 5 / 1,100 |
Outcome results
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.
Time frame: This outcome is determined within 1 month after colonoscopy
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Golytely | Colonoscopy Completion Rate | 591 Participants |
| Miralax-Gatorade Prep | Colonoscopy Completion Rate | 600 Participants |
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.
Time frame: within 1 month of colonoscopy
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Golytely | Population Level Adenoma Detection Rate (ADR) | 383 Participants |
| Miralax-Gatorade Prep | Population Level Adenoma Detection Rate (ADR) | 364 Participants |
Adequate Bowel Prep Quality
this is a binary indictor based on endoscopist rating of excellent or good quality bowel preparation
Time frame: within 1 month after the colonoscopy
Cancellation or No-show in Each Bowel Prep Arm
The proportion of patients who cancel or no-show in each group.
Time frame: within 1 month after colonoscopy
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Golytely | Cancellation or No-show in Each Bowel Prep Arm | 358 Participants |
| Miralax-Gatorade Prep | Cancellation or No-show in Each Bowel Prep Arm | 330 Participants |
Hyponatremia
Hyponatremia
Time frame: within 6 months after colonoscopy
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
Time frame: within 1 month after colonoscopy
Renal Failure
renal failure documented in CPRS
Time frame: within 6 months of colonoscopy