Adenoma detection rate in high-risk patients differs from that in average-risk patients

Background: Adenoma detection rates (ADRs) are established as quality targets in average-risk (AR) individuals undergoing colorectal cancer (CRC) screening colonoscopy. Little is known about the ADR in high-risk (HR) individuals undergoing index or surveillance colonoscopy. Objective: To determine and compare ADR in HR versus AR individuals undergoing colonoscopy. Design and Setting: Retrospective study, tertiary care center. Patients and Intervention: We reviewed records of 7357 patients who underwent colonoscopy by 66 multispecialty endoscopists at our institution during the period 2008 to 2009. Both screening and surveillance colonoscopies in AR and HR patients for CRC were studied. HR patients were further divided into 3 subgroups: those with a (1) personal history of polyps (PHP), (2) family history of polyps (FHP), and (3) family history of CRC (FHCRC). Multivariable logistic regression analysis was performed to evaluate differences in ADR between the groups after adjusting for possible confounders. Main Outcome Measurements: ADR in HR patients. Results: The study included 4141 patients, of whom 2170 were AR and 1971 were HR. Patients in the HR group were older (64.5 +/- 9.1 years vs 59.1 +/- 7.9 years, P <.001). HR patients were more likely to have adenomas (30.7% vs 25.6%, P <.001). Adenomas were detected more often in the proximal colon than in the distal colon (29.3% vs 21.0%, P <.001 and 22.8% vs 15.8%, P <.001, respectively). Patients with a PHP had the highest ADR (33.1%, P <.001). However, after adjusting for confounders, HR status was not found to be associated with ADR (odds ratio [OR] 1.2; 95% confidence interval [CI], 0.93-1.6; P =.15 for females and 0.93; 95% CI, 0.70-1.2; P =.61 for males). HR females were found to have a 40% greater likelihood of having proximal adenomas than AR females (1.4; 95% CI, 1.01-2; P =.04). Limitations: Retrospective design, single tertiary center. Conclusions: Patients with a PHP have a significantly higher ADR compared with AR patients. Defining a minimum target ADR for individuals with a PHP undergoing surveillance colonoscopy is important.