Effectiveness of 1-L polyethylene glycol plus ascorbate versus 4-L polyethylene glycol for colonoscopy cleansing in split-dose: a multicentre, randomized, clinical trial (OVER2019)

Aims Adequate bowel cleansing is essential for a HQ colonoscopy. A novel 1-L polyethylene glycol plus ascorbate (1L-PEG+ASC) solution has been recently introduced. Nevertheless, the effectiveness of 1L-PEG+ASC over high-volume bowel preparations in IPs and OPs is still unclear.

Methods In a single-blinded phase-IV study, patients undergoing colonoscopy were randomized 1:1 to receive split-dose 1L PEG+ASC or a split-dose 4-L PEG-based regimen in 10 Italian centers. Preparation was assessed with the BBPS by local blinded colonoscopists. The primary endpoint was noninferiority of 1L-PEG+ASC in CS. Secondary endpoints were EC, HQC-RC, PDR, ADR, patient compliance and safety ([Table 1]).

Table 1  Patient characteristics in the full analysis set (n = 446).

Results 478 pts were randomized: 242 to 4L-PEG and 236 to 1L-PEG+ASC.The 1L-PEG+ASC showed higher cleansing success rate (98.4% vs 96.0%;[RR], 2.207; 95% [CI], 1.207-4.033; p=.009), excellent cleansing (39.1% vs 27.7%; RR, 1.675; 95% [CI], 1.118-2.510; p=.012) and HQC-RC (52.3% vs 38.5%; RR, 1.750; 95% [CI], 1.194-2.564; p=.004).No differences in PDR (34.1% vs 32.9%, p=.787), ADR (25.5% vs 23.5%, p=.632) were found; also in subgroup analysis (OPs vs IPs), the 1L-PEG+ASC showed higher BBPS (7.8 ± 1.4 vs 7.4 ± 1.7; p=.035), CS (96.3% vs 88.6%; p=.018) and HQC-RC (62.2% vs 46.3%; p=.010)in OPs. Compliance and safety were comparable between the two arms. No serious AEs or deaths occurred ([Table 2]).

Table 2  Bowel cleansing outcomes

Conclusions The 1L-PEG+ASC showed higher effectiveness compared with 4L-PEG in achieving adequate CS, with similar compliance, tolerability and safety both in OPs and IPs.

Conflicts of interest

Authors do not have any conflict of interest to disclose.

Publication History

Article published online:
14 April 2023