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

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