Assessment of quality in screening colonoscopy for colorectal cancer

Introduction: The effectiveness of screening colonoscopy in decreasing the incidence of colorectal cancer (CRC) is largely dependent on the detection of polyps and the quality of the procedure. Several key quality measures have been proposed to improve the effectiveness of screening colonoscopies. Aim: To evaluate quality indicators of screening colonoscopy in a tertiary hospital. Methods: All CRC screening colonoscopies performed between 2005 and 2009 in a single tertiary center were reviewed for internationally accepted quality measures. Results: Of the 1545 individuals who underwent first-time screening colonoscopy 38% were male and 62% were female. The mean age of the patients was 60.4 years and the mean difference in ages was +/- 10.3 years. Cecal intubation rate was 91% (1336), however ileocecal valve photo documentation was performed in only 81% (1248) colonoscopies. The quality of bowel -preparation was classified as: good 76% (1171), reasonable 11% (174), and poor 13% (200). Polyp detection rate (PDR) was 33% (503). The prevalence of polyps >= 1 cm in size was 5% (82). PDR was significantly higher in men than in women (44% [260] vs 25% [243], P = 0.0001). Other factors significantly influencing PDR were quality of bowel preparation (odds ratio [OR]: 1.28, 95% confidence interval [CI]: 0.9-1.6) and age over 50 (OR: 1.9, 95% CI: 1.3-2.9). Left colonic polyps were associated with a risk ratio of 2.3 (95% CI: 1.8-2.9) of lesions in the other colonic segments compared to no polyps in the left colon. None of the colonoscopists reported withdrawal time. Conclusion: Cecal intubation rate and quality of bowel preparation were suboptimal. The polyp detection rate compares favorably to accepted standards and its main determinants are male sex, age >50 years, quality of bowel preparation, and the presence of left colonic polyps.