Nonneoplastic polypectomy during screening colonoscopy: the impact on polyp detection rate, adenoma detection rate, and overall cost.

BACKGROUND: The frequency of nonneoplastic polypectomy (NNP) and its impact on the polyp detection rate (PDR) is unknown. The correlation between NNP and adenoma detection rate (ADR) and its impact on the cost of colonoscopy has not been investigated. OBJECTIVE: To determine the rate of NNP in screening colonoscopy, the impact of NNP on the PDR, and the correlation of NNP with ADR. The increased cost of NNP during screening colonoscopy also was calculated. DESIGN: We reviewed all screening colonoscopies. PDR and ADR were calculated. We then calculated a nonneoplastic polyp detection rate (patients with ≥1 nonneoplastic polyp). SETTING: Tertiary-care referral center. PATIENTS: Patients who underwent screening colonoscopies from 2010 to 2011. INTERVENTIONS: Colonoscopy. MAIN OUTCOME MEASUREMENTS: ADR, PDR, NNP rate. RESULTS: A total of 1797 colonoscopies were reviewed. Mean (±standard deviation) PDR was 47.7%±12.0%, and mean ADR was 27.3%±6.9%. The overall NNP rate was 10.4%±7.1%, with a range of 2.4% to 28.4%. Among all polypectomies (n=2061), 276 were for nonneoplastic polyps (13.4%). Endoscopists with a higher rate of nonneoplastic polyp detection were more likely to detect an adenoma (odds ratio 1.58; 95% confidence interval, 1.1-1.2). With one outlier excluded, there was a strong correlation between ADR and NNP (r=0.825; P<.001). The increased cost of removal of nonneoplastic polyps was $32,963. LIMITATIONS: Retrospective study. CONCLUSION: There is a strong correlation between adenoma detection and nonneoplastic polyp detection. The etiology is unclear, but nonneoplastic polyp detection rate may inflate the PDR for some endoscopists. NNP also adds an increased cost. Increasing the awareness of endoscopic appearances through advanced imaging techniques of normal versus neoplastic tissue may be an area to improve cost containment in screening colonoscopy.