Adenoma detection rate and tolerability of 2 ultra-low-volume bowel preparations in screening: a noninferiority randomized controlled trial

The adenoma detection rate (ADR), recognized as a surrogate marker for colorectal cancer (CRC) incidence and mortality reduction, is closely linked to the efficacy of bowel cleansing. However, there is a dearth of evidence examining the impact on ADR when using 2 distinct very-low-dose bowel cleansing products. This study sought to compare ADR in an immunochemical fecal occult blood test (iFOBT)-based organized screening program by using 1 L of polyethylene glycol plus ascorbate (1L-PEGA) versus sodium picosulfate with magnesium citrate (SPMC), both administered in a split-dose regimen. We conducted a comparative, parallel, randomized, noninferiority, and low-intervention clinical trial targeting individuals from a population CRC screening program aged 50 to 69 years with a positive iFOBT result scheduled for a workup colonoscopy in the morning. Participants were randomized to either 1L-PEGA or SPMC for bowel cleansing. The main outcome was ADR, whereas secondary outcomes were bowel preparation quality, safety, tolerability, and satisfaction. A total of 1002 subjects, 501 were included in each group. There were no differences between groups with respect to pooled ADR (SPMC, 56.5% [95% CI, 52.1-60.8]; 1L-PEGA, 53.7% [95% CI, 49.3-58.0]; relative risk, .95 [95% CI, .85-1.06]); therefore, SPMC demonstrated noninferiority in ADR compared with 1L-PEGA (difference, 2.8%; 2-sided 95% lower confidence limit, –3.4). In addition, there were no significant differences in mean lesions regardless of size and location between arms. Bowel preparation favored 1L-PEGA (96.2% vs 89.2%, P < .001), whereas SPMC exhibited significantly higher safety and tolerability, as shown by fewer nonserious treatment-emergent adverse events. SPMC emerged as a noninferior laxative compared with 1L-PEGA concerning ADR. Despite the superior bowel preparation quality associated with 1L-PEGA, the safety, tolerability, and overall satisfaction of participants were higher with SPMC. (Clinical trial registration number: EudraCT: 2019-003186-18.)