Meta-Analysis
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World J Meta-Anal. May 26, 2013; 1(1): 10-15
Published online May 26, 2013. doi: 10.13105/wjma.v1.i1.10
Ascorbic acid and low-volume polyethylene glycol for bowel preparation prior to colonoscopy: A meta-analysis
Jonathan D Godfrey, Robert E Clark, Abhishek Choudhary, Imran Ashraf, Michelle L Matteson, Srinivas R Puli, Matthew L Bechtold
Jonathan D Godfrey, Robert E Clark, Abhishek Choudhary, Imran Ashraf, Michelle L Matteson, Matthew L Bechtold, Division of Gastroenterology, University of Missouri, Columbia, MO 65212, United States
Srinivas R Puli, OSF MG Gastroenterology, University of Illinois, Peoria, IL 61604, United States
Author contributions: Godfrey JD, Clark RE and Bechtold ML were responsible for the conception and design of the study; Godfrey JD, Clark RE, Choudhary A and Ashraf I collected the data and organized data extraction sheets; Matteson ML, Puli SR and Bechtold ML statistically analyzed the data; Godfrey JD and Clark RE drafted the manuscript with critical revision being performed by Ashraf I, Choudhary A, Matteson ML, Puli SR and Bechtold ML.
Correspondence to: Matthew L Bechtold, MD, FACG, Division of Gastroenterology, University of Missouri, Health Sciences Center, Five Hospital Drive, Columbia, MO 65212, United States. bechtoldm@health.missouri.edu
Telephone: +1-573-8821013 Fax: +1-573-8844595
Received: February 19, 2013
Revised: March 20, 2013
Accepted: April 9, 2013
Published online: May 26, 2013
Abstract

AIM: To evaluate the benefits of low-volume polyethylene glycol (PEG) with ascorbic acid compared to full-dose PEG for colonoscopy preparation.

METHODS: MEDLINE, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, CINAHL, PubMed, and recent abstracts from major conferences were searched (January 2012). Only randomized-controlled trials on adult subjects comparing low-volume PEG (2 L) with ascorbic acid vs full-dose PEG (3 or 4 L) were included. Meta-analysis for the efficacy of low-volume PEG with ascorbic acid and full-dose PEG were analyzed by calculating pooled estimates of number of satisfactory bowel preparations as well as adverse patient events (abdominal pain, nausea, vomiting). Separate analyses were performed for each main outcome by using OR with fixed and random effects models. Heterogeneity was assessed by calculating the I2 measure of inconsistency. RevMan 5.1 was utilized for statistical analysis.

RESULTS: The initial search identified 242 articles and trials. Nine studies (n = 2911) met the inclusion criteria and were analyzed for this meta-analysis with mean age range from 53.0 to 59.6 years. All studies were randomized controlled trials on adult patients comparing large-volume PEG solutions (3 or 4 L) with low-volume PEG solutions and ascorbic acid. No statistically significant difference was noted between low-volume PEG with ascorbic acid and full-dose PEG for number of satisfactory bowel preparations (OR 1.07, 95%CI: 0.86-1.33, P = 0.56). No statistically significant difference was noted between low-volume PEG with ascorbic acid and full-dose PEG for abdominal pain (OR 1.09, 95%CI: 0.81-1.48, P = 0.56), nausea (OR 0.70, 95%CI: 0.49-1.00, P = 0.05), or vomiting (OR 0.99, 95%CI: 0.78-1.26, P = 0.95). No publication bias was noted.

CONCLUSION: Low-volume PEG with the addition of ascorbic acid demonstrates no statistically significant difference to full-dose PEG for satisfactory bowel preparation and side-effects.

Keywords: Polyethylene glycol, Ascorbic acid, Colonoscopy, Meta-analysis, Bowel preparation

Core tip: Optimal visualization of the colon during colonoscopy requires adequate bowel preparation that is effective and tolerable to the patient. Low-volume polyethylene glycol (PEG) preparation coupled with ascorbic acid has been utilized to enhance patient tolerability without affecting the quality of bowel preparation. This meta-analysis shows that bowel preparation with low-volume PEG with ascorbic acid does not differ from full-dose PEG for quality of bowel preparation or patient tolerability.