Shorter time between bowel prep completion and colonoscopy initiation is associated with improved bowel prep adequacy, but not necessarily adenoma detection rates, according to results of a meta-analysis.
In the pooled analysis, shorter intervals between bowel prep and colonoscopy were associated with adequate preparation 94% of the time (95% CI, 91%-97%), which was significantly greater than the adequacy rate seen with longer intervals (84%; 95% CI, 79%-89%) (Turk J Gastroenterol 2023; 34[1]: 26-34).
The meta-analysis included data from 20 studies that reported results with regard to the time interval between bowel prep completion and colonoscopy. Ten of the studies were randomized controlled trials, six were non-randomized prospective studies and four were retrospective studies. In total, 10,341 participants were included in the 20 studies.
Although there was variability in what individual studies defined as a short versus a long interval, when analyzing specific time intervals, there was a time-dependent trend. Adequacy rates were highest for intervals of less than five hours (94%; 95% CI, 92%-97%), closely followed by rates for intervals of six to 11 hours (92%; 95% CI, 86%-96%), with the lowest rates for intervals of 11 to 20 hours (85%; 95% CI, 77%-91%) and more than 20 hours (85%; 95% CI, 76%-92%).
Shorter prep-to-colonoscopy intervals (47%; 95% CI, 27%-68%) also were associated with higher polyp detection rates than longer intervals (30%; 95% CI, 24%-38%) in the analysis. However, there was wide variability in the individual study estimates for polyp detection rate in short intervals, which resulted in a relatively imprecise pooled estimate with a confidence interval that overlapped with that of the pooled estimate of the longer intervals.
Of note, the researchers found no difference in the adenoma detection rates of the short (18%; 95% CI, 9%-29%) versus long (19%; 95% CI, 15%-22%) prep-to-colonoscopy intervals.
The researchers stated that further studies are needed to determine “an optimal time interval between bowel preparation and colonoscopy,” given the fact that it is a relatively easily “modifiable factor” that can “improve diagnostic efficiency and reduce health care costs.”
The variability in the definitions of short and long intervals and the bowel prep quality scales used across studies were noted limitations of the meta-analysis. Thus, the researchers recommend standardization of these definitions and consideration of patient health literacy and risk factors for poor bowel prep adequacy in future studies to help define “individualized bowel preparation schedule[s]” to optimize quality.
—Natasha Albaneze, MPH