Meta-Analysis
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Dec 16, 2018; 10(12): 422-441
Published online Dec 16, 2018. doi: 10.4253/wjge.v10.i12.422
Sodium picosulphate or polyethylene glycol before elective colonoscopy in outpatients? A systematic review and meta-analysis
Rodrigo Silva de Paula Rocha, Igor Braga Ribeiro, Diogo Turiani Hourneaux de Moura, Wanderley Marques Bernardo, Maurício Kazuyoshi Minata, Flávio Hiroshi Ananias Morita, Júlio Cesar Martins Aquino, Elisa Ryoka Baba, Nelson Tomio Miyajima, Eduardo Guimarães Hourneaux de Moura
Rodrigo Silva de Paula Rocha, Igor Braga Ribeiro, Diogo Turiani Hourneaux de Moura, Wanderley Marques Bernardo, Maurício Kazuyoshi Minata, Flávio Hiroshi Ananias Morita, Júlio Cesar Martins Aquino, Elisa Ryoka Baba, Nelson Tomio Miyajima, Eduardo Guimarães Hourneaux de Moura, Gastrointestinal Endoscopy Unit, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-010, Brazil
Diogo Turiani Hourneaux de Moura, Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, United States
Author contributions: Rocha RSP acquisition of data, analysis, interpretation of data, drafting the article, revising the article, final approval; Bernardo WM analysis and interpretation of data, drafting the article, final approval; Ribeiro IB acquisition of data, drafting the article, revising the article, final approval; de Moura DTH analyzed and interpreted of data, revised the article; Minata MK acquisition of data, drafting the article, revising the article, Morita FHA acquisition of data, drafting the article, revising the article; Aquino JCM drafting the article, revising the article; de Moura EGH, Baba ER and Miyajima NT analysis and interpretation of data, drafting the article, revising the article, final approval; de Moura EGH: conception and design of the study, critical revision, final approval.
Conflict-of-interest statement: The authors deny any conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author to: Igor Braga Ribeiro, MD, Academic Fellow, Surgeon, Gastrointestinal Endoscopy Unit, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Enéas de Carvalho Aguiar 255, Instituto Central, Prédio dos Ambulatórios, Pinheiros, São Paulo 05403-000, Brazil. igorbraga1@gmail.com
Telephone: +55-92-981377788 Fax: +55-11-26616467
Received: August 8, 2018
Peer-review started: August 9, 2018
First decision: October 4, 2018
Revised: October 17, 2018
Accepted: December 4, 2018
Article in press: December 5, 2018
Published online: December 16, 2018
Processing time: 135 Days and 8.6 Hours
ARTICLE HIGHLIGHTS
Research background

Colonoscopy reduces the incidence and mortality for colorectal cancer. Bowel preparation is the cornerstone for colonoscopy as the quality of bowel cleaning directly affects the effectiveness for detecting neoplastic lesions. Different options of purgatives exist as a result of the search for the ideal product and none of them have all the ideal features. PEG solutions are the most widely used and studied bowel cleanser, while SPMC is a recently developed one to overcome PEG’s poor palatability and large volume of solution to be ingested. Meta-analyses of RCTs are the best evidence for medical practice, but none of them compared SPMC and PEG for outpatients before colonoscopy, leaving a gap in the literature.

Research motivation

Most of elective colonoscopies are performed in outpatients and inpatient status is an independent risk factor for inadequate bowel preparation. As previous meta-analyses comparing SPMC and PEG before elective colonoscopy did not consider patient status for inclusion criteria, there is no established evidence for this subset of patients.

Research objectives

To determine the best option for bowel preparation in adult outpatients before elective colonoscopy by comparing cleaning efficacy, tolerability, AE prevalence, PDR and ADR between SPMC and PEG. This is the first meta-analysis to include only outpatients and to communicate effectiveness using NNT.

Research methods

Systematic review and meta-analysis followed PRISMA Statement. Eligibility criteria were based on PICOS strategy. Search was performed in MEDLINE, Scopus, EMBASE, CENTRAL/Cochrane, CINAHL and LILACS. Jadad scale was the tool adopted to evaluate the methodological quality of included RCTs and heterogeneity among studies was assessed by Higgins’ test (I2). Meta-analysis was preferably performed using intention-to-treat data by computing risk difference (RD) for dichotomous outcomes using Mantel-Haenszel (MH) method and NNT calculated for each outcome with statistical difference.

Research results

Sixteen RCTs with 6200 subjects were included for the meta-analysis and high heterogeneity was found among them. Sensitivity analysis and sub analysis by type of regime, volume of PEG solution and dietary recommendations were performed to interpret data. In the overall analysis, SPMC was better for bowel cleaning [RD 0.03, IC (0.01, 0.05), NNT 34], for tolerability [RD 0.08, IC (0.03, 0.13), NNT 13] and for adverse events [RD 0.13, IC (0.05, 0.22), NNT 7]. The small NNT for adverse events (NNT of 7) reveals a reduction of 14.2% when SPMC is used. Better tolerability for SPMC was also found in “Day-before preparations” [RD 0.17, IC (0.13, 0.21), NNT 6], “According to interval time” [RD 0.08, IC (0.01, 0.15), NNT 13], “Against high-volume of PEG” [RD 0.08, IC (0.01, 0.14), NNT 13] and “Liquid diet subgroup” [RD 0.14, IC (0.06,0.22), NNT 8].

Research conclusions

Data from published RCTs suggests SPMC is a better bowel cleanser than PEG before elective colonoscopy for healthy and mildly diseased adult outpatients because of its better tolerability, lower AE prevalence and cleaning efficacy at least equal to that of PEG. For split preparations, SPMC and PEG can be equally use, but for day-before preparations SPMC should be the standard choice.

Research perspectives

Future RCTs might influence the outcomes of this meta-analysis with few studies included and/or with borderline differences obtained (e.g., PDR, ADR, per type of regimen and per dietary recommendations) since Meta-analyzes are limited by the number of studies available and by the quality of the studies included. More homogeneous and definitive results should be obtained through a large intercontinental multi-center RCT, with the same bowel preparation protocol and tools for evaluating results. Although expensive and hard-working, it would be the best study format to compare purgatives and determine the best conditions for each of the available purgatives.