title: Meta-analysis: The effect of patient education on bowel preparation for colonoscopy.
abstract: OBJECTIVE
  The proportion of outpatients with inadequate bowel preparation before colonoscopy is high owing to patient unawareness of its importance and poor adherence to instructions. This meta-analysis aimed to determine the effect of educational intervention on the quality of bowel preparation before colonoscopy.
  
  
  METHODS
  A comprehensive literature review identified randomized controlled trials measuring the effect of educational intervention on the quality of bowel preparation. Two reviewers independently screened relevant articles, extracted data, and assessed the risk of bias. The primary outcome was the quality of each bowel preparation before colonoscopy, using a particular assessment scale. The secondary outcomes were polyp detection rates during the procedure and the need for a repeat colonoscopy due to incomplete examination.
  
  
  RESULTS
  Nine randomized controlled trials were included in this meta-analysis. In all, 2885 patients were enrolled, with 1458 receiving education and 1427 assigned to the control group. An educational intervention before colonoscopy significantly improved bowel preparation (relative risk [RR] = 1.22; 95 % confidence interval [CI], 1.10 - 1.36), however, no significant differences were identified in polyp detection rates (RR = 1.14; 95 %CI 0.87 - 1.51) or the need for repeat colonoscopy (RR = 0.52; 95 %CI 0.25 - 1.04) between the groups. Asymmetry in the appearance of the funnel plot and the result of Egger test (P < 0.001) suggested that publication bias existed.
  
  
  CONCLUSIONS
  Evidence from these randomized controlled trials shows that a brief counseling session with patients before colonoscopy ensures better bowel preparation. However, evidence is insufficient to assess improvements in polyp detection rate and avoidance of a repeat colonoscopy. Despite these encouraging observations, this meta-analysis had some limitations, including potential publication bias and significant heterogeneity of the types of bowel purgatives. These results should be interpreted with caution.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; Evidence Base Medicine Center, Department of Medical Education, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Chen-Wang
authors.initials: CW
authors.lastname: Chang
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Shou-Chuan
authors.initials: SC
authors.lastname: Shih
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Horng-Yuan
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Cheng-Hsin
authors.initials: CH
authors.lastname: Chu
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Tsang-En
authors.initials: TE
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan.
authors.forename: Chien-Yuan
authors.initials: CY
authors.lastname: Hung
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Tze-Yu
authors.initials: TY
authors.lastname: Shieh
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Yang-Sheng
authors.initials: YS
authors.lastname: Lin
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan ; Evidence Base Medicine Center, Department of Medical Education, Mackay Memorial Hospital, Taipei, Taiwan ; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan ; MacKay Medical College, New Taipei, Taiwan.
authors.forename: Ming-Jen
authors.initials: MJ
authors.lastname: Chen