Split-Dose Polyethylene Glycol Is Superior to Single Dose for Colonoscopy Preparation: Results of a Randomized Controlled Trial

Vitamin drinks improve palatability and reduce adverse events associated to polyethylene glycol electrolyte solutions

Background

The unpleasant taste of polyethylene glycol (PEG) has been a hindrance to patients undergoing colonoscopy.

Aim

This study aims to determine whether the addition of a vitamin drink (Mizone) to the 4L split-dose PEG regimen would be effective in improving the solution's palatability, and reducing patient discomfort during bowel preparation.

Methods

The present prospective, single endoscopist-blinded, randomized controlled study randomly assigned patients into two groups: PEG + Mizone group (3.6 L of PEG solution plus 0.4 L of Mizone) and PEG group (4 L of PEG solution). Palatability was assessed using a Likert scale of 1-5. The adverse events, amount of unconsumed solution, and willingness to repeat the same process were recorded through a questionnaire. The present study was registered in the Chinese Clinical Trial Registry (ChiCTR2000034484).

Results

A total of 132 patients were included. The demographic characteristics of these patients were comparable between the two groups. The palatability score (mean ± standard deviation [SD]) was higher in the PEG + Mizone group, when compared to the control group (4.00 ± 0.859 vs. 2.95 ± 0.999, p < 0.001). Furthermore, the incidence of nausea was lower in the PEG + Mizone group (9.1 % vs. 28.8 %, p = 0.004), while the other adverse events were similar between the two groups. The percentage of the completely consumed pre-prepared solution was significantly greater in the PEG + Mizone group (95.5 % vs. 78.8 %, p = 0.004). Furthermore, the willingness to repeat the same process was higher in the PEG + Mizone group (83.3 % vs. 42.4 %, p < 0.001). However, the consumption of either of these preparations did not significantly affect the electrolyte and blood glucose levels, and renal function.

Conclusion

Compared to the conventional 4L PEG bowel preparation, the use of a vitamin drink (Mizone) as an adjuvant can improve the palatability, reduce adverse events, and increase the patient's willingness to undergo bowel preparation with the same regimen.

Examining linaclotide for the treatment of chronic idiopathic constipation

INTRODUCTION

Chronic idiopathic constipation (CIC) is characterized by infrequent bowel movements and hard stools lasting for at least three months or longer. This disease affects 8-12% of the US population and 10-17% of the world population. Treatment and management involve identifying the primary cause, changing dietary habits, and adequate physical activity. Linaclotide is a guanylate cyclase-agonist acting locally in the luminal surface of the intestinal enterocyte leading to a signal transduction cascade, activation of the cystic fibrosis transmembrane conductance regulator (CFTR), thus increasing secretion of chloride and bicarbonate into the intestinal lumen with eventual increased intestinal fluid and faster transit time.

AREAS COVERED

We reviewed multiple studies and did a thorough literature review on CIC including its pathophysiology. Through this literature review, we were able to discuss and give the context and rationale for drug regimens indicated for CIC.

EXPERT OPINION

The era we live in right now is akin to nutrient-rich and fertilized soil as knowledge and resources are abundant. The opportunities and potential are endless. Constipation being more extensively studied, our understanding of medications and diseases broadens, leading to novel medications being discovered. Linaclotide is a pioneer in this aspect and can pave the way for future generations.

Prospective, randomized study comparing two different regimens of split-dose polyethylene glycol and their effect on endoscopic outcomes

BACKGROUND

Different split regimens of polyethylene glycol are routinely used and no guidelines are available to select an optimal protocol of ingestion. This study aims to compare the efficacy and side effect profile of two different regimens of polyethylene glycol bowel preparation solution: PEG (3 + 1) vs. PEG (2 + 2).

METHODS

240 patients above the age of 18 years were included in the study between June 1st and November 31st, 2023. Patients were randomly assigned either to Group A, consisting of 115 patients receiving a 3 L of PEG the night before the colonoscopy, and 1 L the same morning of the procedure. Or to group B, where 125 patients ingested 2 L the night before the procedure, and the remaining 2 L the same morning. The cleansing efficacy was evaluated by the attending endoscopist using the Boston Bowel Preparation Scale, through a score assigned for each segment of the colon (0-3). Side effects, tolerability, and willingness to retake the same preparation were listed by an independent investigator using a questionnaire administered before the procedure.

RESULTS

A higher percentage of patients had gastric fullness with the 3 + 1 vs. 2 + 2 preparation (58.3% vs. 31.2%; p <.001). A higher Boston bowel preparation score was seen in patients who took the 2 + 2 vs. 3 + 1 preparation (7.87 vs. 7.23). Using the 2 + 2 preparation was significantly associated with higher Boston bowel preparation scores vs. the 3 + 1 preparation (OR = 1.37, p =.001, 95% CI 1.14, 1.64). After adjustment over other variables (age, gender, comorbidities, previous abdominal surgeries, presence of adenoma, and time between last dose and colonoscopy), results remained the same (aOR = 1.34, p =.003, 95% CI 1.10, 1.62).

CONCLUSION

While both (2 + 2) and (3 + 1) regimens of polyethylene glycol are a good choice for a successful colonoscopy, we recommend the use of (2 + 2) regimen for its superior efficacy in bowel cleansing.

Bowel preparation efficacy and safety of compound polyethylene glycol electrolyte powder combined with linaclotide for colonoscopy: A randomized controlled trial

Background and Aim

Adequate bowel preparation is essential for colonoscopy, which is important for detecting colon polyps and preventing colorectal cancer. Linaclotide is approved for irritable bowel syndrome with predominant constipation (IBS-C) symptoms. The main objective of this study was to explore the quality of bowel preparation by low-volume compound polyethylene glycol (PEG) combined with linaclotide.

Methods

A total of 266 patients who underwent colonoscopy in Shangrao People's Hospital from June 2021 to June 2022 were randomized to 1 of 3 split PEG regimens: 4LPEG, 2LPEG, and 2LPEG + L (linaclotide). The primary end point was adequate bowel preparation (Boston Bowel Preparation Scale [BBPS] total score of ≥6, with each of three colonic segments subscores ≥2). Secondary outcomes were polyp detection rates and the incidence of adverse reactions.

Results

Over 12 months, 266 subjects were randomized into 2LPEG (n = 12), 4LPEG (n = 112), or 2LPEG + L (n = 142). There were no significant differences between the 4LPEG and 2LPEG + L groups in achieving adequate bowel preparation (P > 0.05). The mean BBPS score of the total colon, left hemi-colon, right hemi-colon, and transverse in the 2LPEG + L group was higher than that in the 2LPEG group (P < 0.001). Patient's sleeping quality and the incidence of adverse reactions of 2LPEG + L group were compatible with 2LPEG group, but it was significantly lower than that in 4LPEG group. There was no statistically significant difference in the detection rate of colon polyps between each group.

Conclusion

The quality of bowel preparation of the compound polyethylene glycol electrolyte powder combined with linaclotide is approximately the same as that of 4LPEG, and it can reduce the adverse reactions in the process of bowel preparation, and its intestinal cleansing effect is also better than that of 2LPEG.

Prediction of advanced colorectal neoplasia based on metabolic parameters among symptomatic patients

BACKGROUND AND AIM

Worldwide, colorectal cancer (CRC) is the third most common cancer and ranks second among the leading causes of cancer death. This study aims to devise and validate a scoring system based on metabolic parameters to predict the risk of advanced colorectal neoplasia (ACN) in a large Chinese population.

METHODS

This was a cohort study of 495 584 symptomatic subjects aged 40 years or older who have received colonoscopy in Hong Kong from 1997 to 2017. The algorithm's discriminatory ability was evaluated as the area under the curve (AUC) of the mathematically constructed receiver operating characteristic curve.

RESULTS

Age, male gender, inpatient setting, abnormal aspartate transaminase/alanine transaminase, white blood cell, plasma gamma-glutamyl transferase, high-density lipoprotein cholesterol, triglycerides, and hemoglobin A1c were significantly associated with ACN. A scoring of < 2.65 was designated as "low risk (LR)." Scores at 2.65 or above had prevalence higher than the overall prevalence and hence were assigned as "high risk (HR)." The prevalence of ACN was 32% and 11%, respectively, for HR and LR groups. The AUC for the risk score in the derivation and validation cohort was 70.12%.

CONCLUSIONS

This study has validated a simple, accurate, and easy-to-use scoring algorithm, which has a high discriminatory capability to predict ACN in symptomatic patients. Future studies should examine its predictive performance in other population groups.

Could atmospheric temperature impact on adequate colon cleansing for colonoscopy? An observational, single-institution study

PURPOSE

Several risk factors affecting the adequacy of colon cleansing have been proposed during the last decades. However, less is known about the impact that atmospheric aspects could have on adequacy of the bowel cleansing. The study aimed to investigate if the atmospheric temperature could impact on the bowel cleansing during colonoscopy.

METHODS

A prospective maintained database of the colonoscopies performed since 1^st August 2017 to 31^st March 2020 was retrospective reviewed. The primary outcome of the study was to identify if the atmospheric temperature was associated with inadequate colon cleansing during colonoscopy. Secondary outcome was to identify the other factors associated with an inadequate colon cleansing.

RESULTS

One thousand two hundred twenty patients were enrolled. High atmospheric temperature (> 25 °C) significantly influenced the colon cleansing (p < 0.0001). Adequate colon cleansing was negatively influenced by gender (female patients were associated with higher colon cleansing rate, p = 0.013), diabetes (p < 0.0001), previous pelvic surgery (p = 0.001), use of Beta-Blocker (p = 0.001), anti-platelet (p = 0.017), angiotensin converting enzyme inhibitors (p = 0.001), the adoption of 4 L Poly Ethylene Glycol solution (p = 0.009), single-dose regimen (p < 0.0001) low patients' compliance (p < 0.0001), higher age and body mass index (p < 0.0001 and p = 0.025), lower education levels (p < 0.0001). On the contrary, admission to the ward to perform bowel preparation positively impacted on colon cleansing (p = 0.002).

CONCLUSION

Atmospheric temperature could play an important role in the colon cleansing during colonoscopy, being high temperature (> 25 °C) associated with lower rate of adequate bowel cleansing. However, being this relationship never studied before, these results must be confirmed by other studies.

Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature

Adequate bowel cleansing is critical for a high-quality colonoscopy because it affects diagnostic accuracy and adenoma detection. Nevertheless, almost a quarter of procedures are still carried out with suboptimal preparation, resulting in longer procedure times, higher risk of complications, and higher likelihood of missing lesions. Current guidelines recommend high-volume or low-volume polyethylene glycol (PEG)/non-PEG-based split-dose regimens. In patients who have had insufficient bowel cleansing, the colonoscopy should be repeated the same day or the next day with additional bowel cleansing as a salvage option. A strategy that includes a prolonged low-fiber diet, a split preparation regimen, and a colonoscopy within 5 h of the end of preparation may increase cleansing success rates in the elderly. Furthermore, even though no specific product is specifically recommended in the other cases for difficult-to-prepare patients, clinical evidence suggests that 1-L PEG plus ascorbic acid preparation are associated with higher cleansing success in hospitalized and inflammatory bowel disease patients. Patients with severe renal insufficiency (creatinine clearance < 30 mL/min) should be prepared with isotonic high volume PEG solutions. Few data on cirrhotic patients are currently available, and no trials have been conducted in this population. An accurate characterization of procedural and patient variables may lead to a more personalized approach to bowel preparation, especially in patients undergoing resection of left colon lesions, where intestinal preparation has a poor outcome. The purpose of this review was to summarize the evidence on the risk factors influencing the quality of bowel cleansing in difficult-to-prepare patients, as well as strategies to improve colonoscopy preparation in these patients.

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.

Efficacy and Tolerability of Two Different Low-Volume Split-Dose Polyethylene Glycol Electrolytes Solution Bowel Preparation for Morning Colonoscopy

METHODS

A total of 120 patients were randomized to receive either the control group (n = 64) or the experimental group (n = 65). Patients in the control group adopted the low-volume split-dose regimen one, and patients in the experimental group adopted the low-volume split-dose regimen two. Those randomized to regimen one were instructed to take 0.75 L PEG two hours after dinner the day before the colonoscopy and 1.5 L PEG 4 hours before the colonoscopy. Patients assigned to regimen two were invited to consume 1.5 L PEG two hours after dinner the day before the colonoscopy and 0.75 L PEG 4 hours before the colonoscopy. The quality of bowel preparation, rated according to a Boston Bowel Preparation Scale (BBPS), represented the primary outcome measure. Tolerability, satisfaction, and lesions detection rated were secondary outcomes.

RESULTS

There was no significant difference between the transverse colon and right colon scores between the two groups (P > 0.05). The low-volume split-dose regimen two showed a higher success rate for cleansing of the right colon and overall colon (P < 0.05). For the comparison of the patients' bowel tolerance, there were no statistical differences between the two groups regarding thirst, abdominal pain or abdominal discomfort, abdominal distension, dizziness or headache, anal discomfort, and sleep disturbance (P > 0.05). However, regimen two had significantly less nausea, vomiting, and fatigue than regimen one (24.62% vs. 42.19%, P=0.034; 10.77% vs. 25.00%, P=0.035; 6.15% vs. 21.88%, P=0.010, respectively). Patient-reported satisfaction and willingness to repeat the bowel preparation were significantly higher for low-volume split-dose regimen two than for low-volume split-dose regimen one (P=0.011; P=0.015).

CONCLUSIONS

In early morning colonoscopies, the bowel-cleansing efficacy and patient tolerability of low-volume split-dose regimen two were superior to low-volume split-dose regimen one.

The efficacy and tolerability of sports drink versus water in bowel preparations: a randomised controlled study

Background

An optimal bowel preparation can result in an improved colonoscopy. This study was to compare the effectiveness and safety of the use of a sports drink (Mizone) plus polyethylene glycol (PEG) solution with a water plus PEG solution in bowel preparations.

Methods

This was a randomised controlled study. All of the included patients were randomly divided into the following two groups: the PEG + Mizone group and the PEG + water group. The palatability of the solution was measured through the use of questionnaires. Additionally, bowel cleanliness was evaluated according to the Ottawa Bowel Preparation Scale (OBPS, 0–14, with higher values indicating worse cleanliness), as well as with the aid of colonoscopy videos.

Results

A total of 270 patients were enrolled. The rate of adequate bowel preparation was 74.8% in the PEG + Mizone group and 68.9% in the PEG + water group, with a risk difference of 5.9% (95% CI: − 4.8–16.6%), which indicated noninferiority (noninferiority margin: − 9.5% <  − 4.8%). However, patients rated the palatability (65.9% vs 44.4%, P < 0.001) and willingness to recommend or repeat (88.9% vs 75.6%, P = 0.004) the administration of the PEG + Mizone preparation as being better than those of the PEG + water preparation. The rates of adverse events during the bowel preparations were not significantly different between the two groups, except for bloating (PEG + Mizone vs PEG + water, 4.4% vs 13.3%, P = 0.010).

Conclusion

The concomitant use of PEG + Mizone was a well tolerated and effective bowel preparation, compared with the PEG + water treatment.

Trial registration

ClinicalTrials.gov NCT04247386. Registered on 30 Jan 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06658-2.

High-Quality Colonoscopy: A Review of Quality Indicators and Best Practices

Colorectal cancer (CRC) continues to be the third leading cause of cancer-related deaths in the US. Colonoscopy remains the best preventative tool against the development of CRC. As a result, high-quality colonoscopy is becoming increasingly important. Specifically, recent guidelines have highlighted pre-procedural, peri-procedural, and post-procedural practices, which promise to improve patient outcomes and reduce the mortality and interval cancer rates in patients undergoing colonoscopies. Despite the guidelines and advances in modern endoscopy, the procedure remains provider-dependent, which results in differences in outcomes. As a result, incorporating high-quality colonoscopy approaches early in training is key to improving patient outcomes. Additionally, ensuring that high-quality colonoscopy is practiced widely by endoscopists can lead to the most cost-effective care.

Novel frontiers of agents for bowel cleansing for colonoscopy

The incidence of colorectal cancer (CRC) is characterized by rapid declines in the wake of widespread screening. Colonoscopy is the gold standard for CRC screening, but its accuracy is related to high quality of bowel preparation (BP). In this review, we aimed to summarized the current strategy to increase bowel cleansing before colonoscopy. Newly bowel cleansing agents were developed with the same efficacy of previous agent but requiring less amount of liquid to improve patients’ acceptability. The role of the diet before colonoscopy was also changed, as well the contribution of educational intervention and the use of adjunctive drugs to improve patients’ tolerance and/or quality of BP. The review also described BP in special situations, as lower gastrointestinal bleeding, elderly people, patients with chronic kidney disease, patients with inflammatory bowel disease, patients with congestive heart failure, inpatient, patient with previous bowel resection, pregnant/lactating patients. The review underlined the quality of BP should be described using a validate scale in colonoscopy report and it explored the available scales. Finally, the review explored the possible contribution of bowel cleansing in post-colonoscopy syndrome that can be related by a transient alteration of gut microbiota. Moreover, the study underlined several points needed to further investigations.

Bowel Preparation for Pediatric Colonoscopy

Colonoscopy is an important diagnostic and therapeutic tool in evaluating and treating gastrointestinal tract pathologies. Adequate visualization of the intestinal lumen is necessary for detection of lesions, and thus bowel preparation is a key component of the process. It is estimated that over 25% percent of pediatric patients have sub-optimal bowel preparations, which can lead to longer procedure times, missed pathology, unsuccessful ileal intubation, and possibly repeat procedure/anesthesia. There is no universal protocol for bowel preparation in pediatrics and there is a wide variability of practices around the world. The purpose of this paper is to review the recent published literature regarding bowel preparations for pediatric colonoscopy with focus on published work in the last decade exploring a number of factors involved in bowel preparation including the role of patient education, types of bowel preparation, and their efficacy and safety.

Efficacy and Patient Tolerability of Split-Dose Sodium Picosulfate/Magnesium Citrate (SPMC) Oral Solution Compared to the Polyethylene Glycol (PEG) Solution for Bowel Preparation in Outpatient Colonoscopy: An Evidence-Based Review

Background

Colonoscopy is the gold standard exam for evaluation of colonic abnormalities and for screening and surveillance for colorectal cancer. However, the efficacy of colonoscopy is dependent on the quality of the pre-colonoscopy bowel preparation. Polyethylene glycol (PEG) and sodium picosulfate/magnesium citrate (SPMC) have emerged as two of the most commonly used bowel preparation agents. We conducted an evidence-based review of current evidence to further investigate the efficacy and patient tolerability of split-dose SPMC oral solution compared to PEG solution for colonoscopy bowel preparation.

Methods

A systematic search was performed using Pubmed (MEDLINE), Web of Science, EMBASE, and Cochran Central Register of Controlled Trials databases. All studies on split-dose bowel preparation with SPMC and PEG were reviewed. Relevant studies regarding colonoscopy and bowel preparations were also included. Randomized controlled trials were prioritized due to the high quality of evidence.

Results

Eight randomized controlled trials were included. Split-dose SPMC and PEG were associated with similar results for adequacy of bowel preparation. Split-dose SPMC was associated with increased patient tolerability and compliance.

Conclusion

Split-dose SPMC and PEG are both adequate and safe for bowel preparation for outpatient colonoscopy, with split-dose SPMC being more tolerable for patients. Additional RCTs comparing these and other bowel preparation solutions are necessary to further investigate quality of bowel preparation, patient preference, and cost-effectiveness of the various options.

Constipation in adults

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Efficacy of Single- Versus Split-dose Polyethylene Glycol for Colonic Preparation in Children: A Randomized Control Study

OBJECTIVES

Polyethylene glycol (PEG) is the most effective colon-cleansing agent but volume-related adverse effects are common. Though split-dose PEG is used in adults, no pediatric study so-far has compared split-dose with single-dose PEG. We aimed at comparing the efficacy and tolerability of split-dose versus single-dose PEG for bowel preparation in children.

METHODS

Consecutive children (1-18 years) were randomized into either single-dose or split-dose PEG. Single-dose group received 4000 mL/1.73 m PEG solution day before colonoscopy whereas split-dose group received half dose day before and the remaining half on the day of colonoscopy. Effectiveness of bowel preparation was assessed on Aronchik scale, by the endoscopist who was blinded to the type of preparation. Interobserver variability was analyzed by comparing with independent scoring by the blinded trained endoscopy-nurse. The trial was registered with Clinical Trials Registry of India (Trail number 2017/08/009303).

RESULTS

Of the 220 randomized children, 179 completed the study (split-dose: 93, single-dose: 86). The mean age of the study population was 11.51 (4.82) years (72.6% boys). The efficacy of bowel preparation was better with split-dose (satisfactory preparation:76.34% vs 43.02%, P < 0.001) with almost perfect inter-observer agreement (k = 0.803). Nausea, vomiting, and sleep disturbance were significantly less in split-dose than single-dose group (P < 0.05). Split-dose patients were able to drink PEG solution faster (P = 0.002). Total sleep duration and uninterrupted sleep duration was also better in split-dose group as compared with single-dose (P = 0.001).

CONCLUSIONS

Split-dose PEG is more effective than single-dose regimen for bowel preparation with better tolerability and improved sleep quality in pediatric population.

A randomized clinical prospective trial comparing split-dose picosulfate/ magnesium citrate and polyethylene glycol for colonoscopy preparation

Background

Colonoscopy remains the gold standard for the investigation of abnormalities within the colon. However, its success is highly dependent on the quality of bowel preparation. The objective of this study was to compare the bowel preparation efficacy of picosulfate/magnesium citrate (PMC) vs polyethylene glycol (PEG) in a one-day vs two-day split dose regimen.

Methods

A prospective, randomized, controlled trial was conducted at the Forzani & MacPhail Colon Cancer Screening Centre in Calgary, Canada. 171 colonoscopy outpatients were randomized to split-dose PMC or PEG lavage as well as into one-day split or two-day split regimens in blocks of eight. Bowel preparation quality was recorded in a blinded manner by the endoscopist using the Ottawa Bowel Preparation Scale (OBPS) prior to washing or suctioning. The scale results were analyzed using a two-factor analysis of variance.

Results

141 patients received complete colonoscopies (PMC-71; PEG-70). PEG was found to be superior to PMC (mean OBPS: 4.14 ± 2.64 vs 5.11 ± 3.44, p = 0.019), when adjusted for administration regimen, leading to significantly more adequate bowel preparations (79.7% vs 59.7%, p = 0.007). A two-day split dose was superior to a one-day split dose regimen (mean OBPS: 3.68± 2.82 vs 5.69 ± 3.06, p<0.001). Two-day split dosing also resulted in a better right colon cleanliness score (right bowel OBPS 1.27±0.11 vs 2.10±0.12 for one-day split, P<0.001).

Conclusions

Optimal bowel preparation was achieved with the use of PEG lavage when administered in a two-day split dose regimen. This trial is registered with ClinicalTrials.gov under identifier NCT01415687.