Reinforced education improves the quality of bowel preparation for colonoscopy: An updated meta-analysis of randomized controlled trials

BACKGROUND AND AIMS: Inadequate bowel preparation (BP) is an unfavorable factor that influence the success of colonoscopy. Although standard education (SE) given to patients are proved useful to avoid inadequate BP. Studies concerning the effects of reinforced education (RE) on the quality of BP were inconsistent. The aim of this updated meta-analysis of randomized controlled trial was to compare the quality of BP between patients receiving RE in addition to SE and those receiving SE alone. METHODS: MEDLINE, EMBASE, Web of Science and the Cochrane Library were systemically searched to identify the relevant studies published through April 2019. The primary outcome was the rate of adequate BP. Subgroup analyses were conducted. Secondary outcomes included BP score, adenoma detection rate (ADR), polyp detection rate (PDR), insertion time, withdrawal time, adverse events, >80% purgative intake and diet compliance. Dichotomous variables were reported as odds ratio (OR) with 95% confidence interval (CI). Continuous data were reported as mean difference (MD) with 95%CI. Pooled estimates of OR or MD were calculated using a random-effects model. Statistical heterogeneity was accessed by calculating the I2 value. A P value less than 0.05 was considered significant. RESULTS: A total of 18 randomized controlled trails (N = 6536) were included in this meta-analysis. Patients who received RE had a better BP quality than those only receiving SE (OR 2.59, 95%CI: 2.09–3.19; P<0.001). A higher ADR (OR 1.35; 95%CI: 1.06–1.72; P = 0.020) and PDR (OR 1.24, 95%CI: 1.02–1.50; P = 0.030), shorter insertion (MD -0.76; 95%CI: -1.48-(-0.04); P = 0.040) and withdrawal time (MD -0.83; 95%CI: -1.83-(-0.28); P = 0.003), less nausea/vomiting (OR 0.78; 95%CI: 0.64–0.97; P = 0.020) and abdominal distension (OR 0.72; 95%CI: 0.68–0.92; P = 0.020) were achieved in the RE group. More patients had >80% purgative intake (OR 2.17; 95%CI, 1.09–4.32; P = 0.030) and were compliant with diet restriction (OR 2.38; 95%CI: 1.79–3.17; P<0.001) in the RE group. CONCLUSION: RE significantly improved BP quality, increased ADR and PDR, decreased insertion and withdrawal time and adverse events.