Effect of Low-volume (1L) vs Intermediate-volume (2L) Bowel Preparation on Cost-effectiveness and Quality of Life (RESULT)

Effect of Low-volume (1L) vs Intermediate-volume (2L) Bowel Preparation on Cost-effectiveness and Quality of Life

Effect of Low-volume (1L) vs Intermediate-volume (2L) Bowel Preparation on Cost-effectiveness and Quality of Life (RESULT Study). A Multicenter Randomized Controlled Trial

Adequate bowel preparation for colonoscopy is paramount for optimal diagnostic accuracy and safety. However, the need for high volumes to clean the colon often makes it difficult for patients to adhere to. Therefore, new low volume bowel preparation fluids have been developed. Little is known on the impact of these low volume bowel preparation fluids (1L), compared to intermediate-volume (2L) laxatives on quality of life (QoL) and cost-effectiveness. This study aims to provide further evidence on the presumed positive effect of ultra-low volume bowel preparation on patients' QoL and cost-effectiveness, in addition to its already demonstrated positive effect on bowel cleansing for colonoscopy. This multicenter randomized controlled trial (RCT) will be conducted in four hospitals in the Netherlands. Secure web-based questionnaires will be used before starting bowel preparation (baseline, t=0) and within 1 week (t=1) after colonoscopy, to assess the impact of bowel preparation on QoL and explore costs and productivity loss for cost-effectiveness analysis.

Background and aims: Adequate bowel preparation for colonoscopy is paramount for optimal diagnostic accuracy and safety. However, the need for high volumes to clean the colon often makes it difficult for patients to adhere to. Therefore, new low volume bowel preparation fluids have been developed. Little is known on the impact of these low volume bowel preparation fluids (1L), compared to intermediate-volume (2L) laxatives on quality of life (QoL) and cost-effectiveness. This study aims to provide further evidence on the presumed positive effect of ultra-low volume bowel preparation on patients' QoL and cost-effectiveness, in addition to its already demonstrated positive effect on bowel cleansing for colonoscopy. Study design: This multicenter randomized controlled trial (RCT) will be conducted in four hospitals in the Netherlands. Secure web-based questionnaires will be used before starting bowel preparation (baseline, t=0) and within 1 week (t=1) after colonoscopy, to assess the impact of bowel preparation on QoL and explore costs and productivity loss for cost-effectiveness analysis. Data on colonoscopy findings and complications will be retrieved from the patients' medical record. Study population: This multicenter study will include 470 patients from 4 hospitals. Intervention: Patients will be randomized during the pre-colonoscopy hospital visit between a specialized low-volume 1-liter bowel preparation fluid (Pleinvue) or an intermediate-volume 2-liter bowel preparation fluid (Moviprep), which are already both routinely used as bowel preparation for colonoscopy in the Netherlands. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: There is no direct benefit for patients participating in this study. Risk associated with participation are considered minimal, and are limited to the possibility of privacy related issues. Nonetheless, this is considered to be minimal because of the use of pseudonymized data and GDPR compliant databases. In the future, results from this study could possibly benefit patients undergoing colonoscopy, with the possibility of reducing the need for repeat colonoscopies and improving patient experience of colonoscopies.

Patients will be randomized during the pre-colonoscopy hospital visit between a specialized low-volume 1-liter bowel preparation fluid (Pleinvue) or an intermediate-volume 2-liter bowel preparation fluid (Moviprep)

a 1L poly ethylene glycol PEG solution with added ascorbate (Pleinvue, Norgine, active ingredients PEG 3350, Sodium ascorbate, Sodium sulfate, Ascorbic acid, Sodium chloride, Potassium chlorid)

a 2L PEG solution with added ascorbate (Moviprep, Norgine, active ingredients Macrogol 3350, Sodium Sulphate Anhydrous, Sodium chloride, Potassium chloride, Ascorbic acid, Sodium ascorbate)

a recently developed 1 liter bowel preparation fluid that is often used in clinical practice. Patients will receive a split dose protocol, low-residue diet 2 days before colonoscopy, and clear liquid diet 1 day before colonoscopy.

a 2 liter widely established 2 liter bowel preparation fluid that is commonly used in clinical practice. Patients will receive a split dose protocol, low-residue diet 2 days before colonoscopy, and clear liquid diet 1 day before colonoscopy.

Level of bowel cleanliness achieved with the bowel preparation used. Segmental scores range from 0 to 3, in which 0 is worst and 3 is best. A segmental score of 2 or more is considered adequate for colonoscopy.

Level of bowel cleanliness achieved with the bowel preparation used. Segmental boston bowel preparation scores range from 0 to 3, in which 0 is worst and 3 is best. A segmental score of 2 or more is considered adequate for colonoscopy.

Change in scoring on the short-form 36 questionnaire before and after bowel preparation. Higher scores indicate a higher quality of life.

Change in scoring on EuroQol group 5Dimension-5Levels questionnaire before and after bowel preparation. Higher scores indicate a higher quality of life.

Correlation of answers to questionaire on tolerability and relation to bowel cleanliness to scoring on SF-36 (short form 36) and EQ-5D-5L (EuroQol group 5 dimensions 5 levels), higher scores indicate a higher quality of life.

Subgroup differences for absolute scores on SF-36 for colonoscopy indication and prior experience with bowel preparation

Change in QoL scores on SF-36 based on having prior experience with bowel preparation, and differences between colonoscopy indications. SF-36 (short form 36), higher scores indicate a higher quality of life.

Change in costs based on having prior experience with bowel preparation, and differences between colonoscopy indications.

Subgroup differences for absolute scores on EQ-5D-5L for colonoscopy indication and prior experience with bowel preparation

Change QoL scores on EQ-5D-5L based on having prior experience with bowel preparation, and differences between colonoscopy indications. EQ-5D-5L (EuroQol group 5 dimensions 5 levels), higher scores indicate a higher quality of life.

Total costs made per individual for the bowel preparation process, including cost for being absent at work and caregiver costs.

Change in costs per quality adjusted life years between the low-volume arm and intermediate volume arm.

advised surveillance interval correlated to colonoscopy findings and BBPS (boston bowel preparation scale) score by the treating physician. Higher scores indicate higher bowel cleanliness

Inclusion Criteria: Age > 18 years Planned elective colonoscopy for surveillance or diagnostic indications Exclusion Criteria: Therapeutic colonoscopy (e.g. endoscopic mucosal resection (EMR) History of (sub) total colectomy Inflammatory bowel disease (IBD) Inpatient status Indication for an intensified bowel preparation regime Emergency colonoscopy Limited Dutch language skills Dementia Visual impairment Commonly accepted contra-indications for non-iso osmotic bowel preparation and ascorbate: Glucose-6-phosphate-dehydrogenase (G6PD) deficiency (sub)ileus Bowel obstruction or perforation Acute abdomen Gastroparesis intolerance for any of the formulation ingredients Severe renal insufficiency (creatinine clearance < 30mL/min) Congestive heart failure (NYHA III or IV) Phenylketonuria

The dataset used during this study is available from the corresponding author upon reasonable request

The dataset used during this study is available from the corresponding author upon reasonable request