Low-Volume Polyethylene Glycol Improved Patient Attendance in Bowel Preparation Before Colonoscopy: A Meta-Analysis With Trial Sequential Analysis

Background: Polyethylene glycol (PEG) has been regarded as the primary recommendation for bowel preparation before colonoscopy. However, a conclusive conclusion has not yet been generated. Aim: We performed this updated meta-analysis to further investigate the comparative efficacy and safety of low volume preparation based on PEG plus ascorbic acid related to 4L PEG. Methods: A systematic search was conducted to retrieve potential randomized controlled trials (RCTs) in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) from January 2000 to April 2018. Two independent searchers critically searched all potential citations, extracted data, and appraised risk of bias accordingly. Moreover, we used the STATA 12.0 and trial sequential analysis (TSA) 0.9 to complete all analyses. Results: A total of 13 RCTs enrolling 3910 patients met inclusion criteria. Meta-analysis based on PP analysis indicated that compared to standard volume PEG regime, low volume regime improved patient compliance (RR=1.01; 95% CIs=1.00,1.03 ; P=0.143 (≥75% intake); RR=1.07; 95% CIs=1.00,1.14; P=0.046 (100% intake), the willingness to repeat the same regime (RR=1.30; 95% CIs=1.07,157; P=0.007) and patient acceptability (RR=1.18; 95% CIs=1.07,1.29; P=0.001), and decreased the overall adverse events (RR=0.86; 95% CIs=0.77,0.96; P=0.009). However, no difference was observed between these two different solutions for bowel preparation efficacy (RR=0.98; 95% CIs=0.95,1.02; P=0.340). These all results were further confirmed by TSA. Conclusions: The effect of low volume regime was not inferior to the standard volume PEG regime, and low volume regime was associated with better compliance when subjects ingested all the solution, willingness to repeat the same regime, higher acceptability and lower nausea in non-selected population.