Specific Verbal vs. Usual Instructions for Inpatients Undergoing Colonoscopy

Introduction Adequate bowel preparation constitutes one of the most important endoscopy quality indicators: it is related with increased detection of pathologic findings, reduces the need for repeated colonoscopies and leads to burden lightening for both patients and endoscopy departments. Different factors have been related to inadequate preparation. Among them, inpatient status has been identified as a major independent risk factor. It has been shown that providing outpatients with simple, but specific instructions regarding the importance and mode of adequate preparation - either through a leaflet, a sms or on the web - improves significantly the level of bowel cleanliness. However, data regarding the success of such an intervention in inpatients lack. Aim To study the impact of providing specific verbal instructions in inpatients (and/or their relatives) undergoing colonoscopy on the quality of bowel preparation. Patients - Methods Study Design This is a prospective, randomized, single-blinded study. Four Greek academic endoscopy departments will competitively enroll patients during a period of 6 months. Randomization A central randomization list will be computer-assisted, created and sent to one collaborator of each center. Endoscopists will be blinded to participant's group. 300 patients will be randomized in 2 groups, in blocks of 10 with an analogy 1:1. They will also be stratified in a 60%-40% percentage depending on whether the patient is bedridden or not at the time of the examination Statistical Analysis According to the literature similar interventions showed a gain of 20% in favor of the intervention. Statistical significance level α is defined 5% and the study is powered at the level of 80%. According to data from Hepatogastroenterology Unit of Attikon University General Hospital regarding the adequateness of bowel preparation of patients undergoing colonoscopy and with an expected 10% drop out, 300 patients are needed (including a 10% drop out) in order to succeed 18% improvement of the primary endpoint (from 66% for inpatients during 2015 to 84% for outpatients during the same period) favoring the intervention group. Interim analysis and sample size re-estimation will be undergone after data collection from 90 patients. Both an intention to treat (ITT) and a per protocol (PP) analysis are planned. Data will be recorded in predefined CRFs.