Educational nurse-led telephone intervention shortly before colonoscopy as a salvage strategy after previous bowel preparation failure: a multicenter randomized trial

Background: The most important predictor of unsuccessful bowel preparation is previous failure. For those patients with previous failure, we hypothesized that a nurse-led educational intervention by telephone shortly before the colonoscopy appointment could improve cleansing efficacy. Methods: We performed a multicenter, endoscopist-blinded, randomized controlled trial. Consecutive outpatients with previous inadequate bowel preparation were enrolled. Both groups received the same standard bowel preparation protocol. The intervention group also received reinforced education by telephone within 48 hours before the colonoscopy. The primary outcome was effective bowel preparation according to the Boston Bowel Preparation Scale. Intention-to-treat (ITT) analysis included all randomized patients. Per-protocol analysis included patients who could be contacted by telephone and the control cases. Results: 657 participants were recruited by 11 Spanish hospitals. In the ITT analysis, there was no significant difference between the intervention and control groups in the rate of successful bowel preparation (77.3 % vs. 72 %; P = 0.12). In the intervention group, 267 patients (82.9 %) were contacted by telephone. Per-protocol analysis revealed significantly improved bowel preparation in the intervention group (83.5 % vs. 72.0 %; P = 0.001). Conclusion: Among all patients with previous inadequate bowel preparation, nurse-led telephone education did not result in a significant improvement in bowel cleansing. However, in the 83 % of patients who could be contacted, bowel preparation was substantially improved. Phone education may therefore be a useful tool for improving the quality of bowel preparation in those cases