Enhanced instructions improve the quality of bowel preparation for colonoscopy: a meta-analysis of randomized controlled trials

Background and Aims The success of a colonoscopy is highly dependent on the quality of bowel preparation (BP). Many patients have poor BP due to non-compliance with regular instructions. Reports concerning the effects of enhanced instructions on BP quality are inconsistent. The aim of this meta-analysis was to compare BP quality between patients receiving enhanced instructions in addition to regular instructions and those who received regular instructions only. Methods MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched to identify relevant studies published for August 2015. The quality of BP (adequate/inadequate), adenoma detection rate, polyp detection rate, willingness to repeat preparation, and adverse events were estimated by using odds ratios (OR) and 95% confidence intervals (CI) with random effects models. Results Eight randomized controlled trials (n = 3795) were included. Patients who received enhanced instructions showed significantly better BP quality than those receiving only regular instructions (OR, 2.35; 95% CI, 1.65-3.35; P < .001). Subgroup analysis showed that the beneficial effects of enhanced instructions on BP quality were consistent among patients receiving different purgative types, administration methods, or diet restriction (all P < .05). Patients in the enhanced instructions group showed more willingness to repeat the preparation (OR, 1.91; 95% CI, 1.20-3.04; P = .006). Conclusions Enhanced instructions significantly improved the quality of BP and willingness to repeat the preparation in patients undergoing colonoscopy. Factors related to patient instructions appear to be as important as the preparation method itself in improving BP quality.