Poster (15W123)

High adenoma detection rate: a prospective analysis of the factors influencing this outcome in Bowelscreen patients.


Ann Cooney, Dr J. Keohane, Dr H. Sengupta


LCH Dundalk, Our Lady Of Loudes, Drogheda


The adenoma detection rate (ADR) is an important metric in the measurement of quality at colonoscopy . ADR OF 25- 35% is expected in a screening colonoscopy. Many factors influence the ADR in particular the quality of bowel preparation and studies show that the ADR is directly proportional to the length of time taken by endoscopists to withdraw from caecum to anus.


To compare our screening endoscopy performance against the standards recommended by the National QA programme for GI endoscopy.


A prospective analysis of data collected from all patients attending for colonoscope on the Bowelscreen programme. Data was collated from the Endoraad (electronic reporting system), patient charts and endoscopy log books. The parameters analysed for this study included bowel preparation adequacy, sedation type /amount, caecal intubation rate, cancer detection rate and ADR. Withdrawal time was calculated from a clearly identifiable appendicle orifice photo and also from the retroflex photo taken in the rectum.


In total 268 colonoscopies were included in this analysis. Scopes were carried out by gastroenterologists only. All patients were between the screening age of 62-70 and all had a positive FIT test. Patients were preassessed and were given both verbal and written instructions on how/when to take their Moviprep© and all patients were given a split dosage regime. Bowel preparation standard achieved, 250 patients( 93.2%) scored excellent /adequate, 18 (6.8%) patients scored poor and had a repeat preparation/CT COLON. Recommended standard >90%. Caecal intubation rate was 95.9%, standard recommended >90%. Caecum was not reached in 11 patients due to pathology encountered (n=9) or patient intolerance (n=2) Intravenous sedation; Midazolam 0-5mgs IV & Fentanyl 0-100mgs was administered. Median administered Midazolam 2.5 /Fentanyl 50mgs.Reversal agents were not required in this cohort. Cancer detection rate was 6.8%. Standard expected 11%. Caecal withdrawal time was 6-105 minutes with an average time for withdrawal 21.86 mins. Recommeded time ;>6mins. ADR was 71.5%, standard recommended 25-35%


Many factors influence ADR. Our ADR is higher than minimum standard rate. Good quality bowel preparation and slow withdrawal times are the two important factors to achieve a high ADR.