The impact of fair colonoscopy preparation on colonoscopy use and adenoma miss rates in patients undergoing outpatient colonoscopy

BackgroundThe impact of fair bowel preparation on endoscopists' recommendations and adenoma miss rates in average-risk patients undergoing colonoscopy is unknown.ObjectiveTo assess the impact of fair bowel preparation on endoscopists' interval colonoscopy recommendations and miss rates in colonoscopies performed within 3 years of the index colonoscopy in average-risk patients undergoing colorectal cancer screening.DesignRetrospective chart review.SettingTertiary-care center.PatientsAverage-risk patients undergoing index colonoscopy for colorectal cancer screening between 2004 and 2006.InterventionColonoscopy.Main Outcome MeasurementsEndoscopists' interval recommendations, adenoma miss rates.ResultsA total of 16,251 colonoscopy records were reviewed over a 2-year period. Of these cases, 1943 colonoscopies were performed for the sole indication of average risk or screening. Of these, fair bowel preparation was reported in 619 patients (31.9%). A repeat colonoscopy within 5 years was recommended in 70.4% of patients. The follow-up colonoscopy compliance rate within 3 years was 55.9%. Adenoma detection rates at index and follow-up colonoscopy were 20.5% and 28.2%, respectively. Of the 39 patients with follow-up colonoscopy within 3 years, the overall adenoma miss rate was 28%. Of the patients with an adenoma identified on follow-up colonoscopy, 13.6% had normal colonoscopy results on index examination.LimitationsRetrospective design.ConclusionFair bowel preparation led to a deviation from national guidelines with early repeat colonoscopy follow-up recommendations in nearly 60% of average-risk patients with normal colonoscopy results. In patients who returned for repeat colonoscopy within 3 years, the overall adenoma miss rate was 28%. Further guidelines on timing for repeat colonoscopy for fair bowel preparation are needed.