Objectives: The impact of bowel preparation on the cost and efficiency of colonoscopy is uncertain. The aim of this study was to measure the impact of bowel preparation on total direct cost as well as procedure time and volume.
Methods: For 200 consecutive outpatient colonoscopies in persons with intact colons both at a private university hospital and at a public university hospital, we recorded the time spent suctioning fluid and feces from the colon and the time spent washing the colon to clean the mucosa. We prospectively asked colonoscopists to designate examinations that should be repeated at an interval sooner than would otherwise be recommended because of imperfect preparation. The data were used to perform a cost analysis of the economic effect of bowel preparation on direct costs of colonoscopy.
Results: Suctioning fluid and washing occupied 6% and 1.5% of total examination time (including insertion and withdrawal) at the public hospital and 9% and 1.3% at the private hospital. Patients at the public hospital were more likely to have an aborted examination (6.5% vs 1%, p = 0.004) and to be brought back earlier than suggested or required by current practice standards because of imperfect bowel preparation (20% vs 12.5%, p = 0.04). Cost analysis indicated that to complete the initial examinations and the first round of surveillance, imperfect bowel preparation resulted in a 12% increase in costs at the university hospital and a 22% increase at the public hospital.
Conclusions: The increase in colonoscopy costs associated with imperfect preparation is substantial, and seems likely to vary among practices. Aborted examinations and surveillance examinations performed earlier than recommended because of imperfect preparation are appropriate targets for continuous quality improvement programs. More reliable bowel preparations, or measures to improve patient compliance with bowel preparation, could significantly reduce the costs of colonoscopy in clinical practice.