Objectives: The success of colonoscopy depends on high-quality bowel preparation by patients; yet inadequate preparation is common. We developed and tested an educational booklet to improve bowel preparation quality.
Methods: We conducted patient cognitive interviews to identify knowledge and belief barriers to colonoscopy preparation. We used these interviews to create an educational booklet to enhance preparatory behaviors. We then prospectively randomized patients scheduled for outpatient colonoscopy at a VA Medical Center to receive usual instructions vs. the booklet before colonoscopy. Patients in both groups received standard pharmacy instructions for single-dose bowel preparation; the protocol did not specify which purgatives to prescribe. The primary outcome was preparation quality based on blinded ratings using the validated Ottawa score. We performed bivariate analyses to compare mean scores between groups using a t-test, and logistic regression to measure the booklet effect on preparation quality, adjusting for potential confounders.
Results: A total of 436 patients were randomized between arms. In an intention-to-treat analysis of the primary outcome, mean Ottawa scores were superior in patients allocated to booklet vs. controls (P=0.03). An intention-to-treat analysis of the secondary outcome revealed a "good" preparation in 68 vs. 46% of booklet and control patients, respectively (P=0.054). In a per-protocol analysis limited to patients who actually received the booklet, preparation was good in 76 vs. 46% patients, respectively (P<0.00001). Regression analysis revealed that booklet receipt increased the odds of good preparation by 3.7 times (95% confidence interval=2.3-5.8).
Conclusions: Provision of a novel educational booklet considerably improves preparation quality in patients receiving single-dose purgatives. The effect of the booklet on split-dose purgatives remains untested and will be evaluated in future research.
Trial registration: ClinicalTrials.gov NCT00975247.