1L- vs. 4L-Polyethylene glycol for bowel preparation before colonoscopy among inpatients: A propensity score-matching analysis

Abstract Background Inpatients are at risk for inadequate colon cleansing. Experts recommend 4L-polyethylene-glycol (PEG) solution. A higher colon cleansing adequacy rate for a hyperosmolar 1L-PEG plus ascorbate prep has been recently reported. Aims We aimed to determine whether 1L-PEG outperforms 4L-PEG among inpatients. Methods post-hoc analysis of a large Italian multicenter prospective observational study among inpatients (QIPS study). We performed a propensity score matching between 1L-PEG and 4L-PEG group. The primary outcome was the rate of adequate colon cleansing as assessed by unblinded endoscopists through Boston scale. Secondary outcome was the safety profile. Results Among 1,004 patients undergoing colonoscopy, 724 (72%) were prescribed 4L-PEG and 280 (28%) 1L-PEG. The overall adequate colon cleansing rate was 69.2% (n = 695). We matched 274 pairs of patients with similar distribution of confounders. The rate of patients with adequate colon cleansing was higher in 1L-PEG than in 4L-PEG group (84.3% vs. 77.4%, p = 0.039). No different shift in serum concentration of electrolytes (namely Na+, K+, Ca2+), creatinine and hematocrit were observed for both preparations. Conclusion We found a higher rate of adequate colon cleansing for colonoscopy with the 1L-PEG bowel prep vs. 4L-PEG, with apparent similar safety profile, among inpatients. A confirmatory randomized trial is needed. (ClinicalTrials.gov no: NCT04310332)