1. The addition of histology to continuous audit has significantly increased adenoma detection rate in a private endoscopy unit
AG Fraser 1, GD Gamble 1, T Rose 2 and the endoscopists of MercyAscot Hospital2, Department of Medicine1, University of Auckland, New Zealand.
The use of polyp detection rate as a surrogate marker for adenoma detection rate is the simplest approach for continuous audit.
This crude index can encourage detection of small non-significant polyps and includes polyps reported as removed but not confirmed at histology.
Recording and feeding back data on polyp histology (in addition to the crude polypectomy rate) may encourage improved detection of significant polyps (adenomas and serrated polyps).
METHODS
Data on polyp histology was added to a continuous audit over a two-year period. Data on age, sex, time to caecum and withdrawal time were recorded.
Data for nine endoscopists with total volume > 150 procedures was compared for polyp detection and withdrawal time (where no polyps were detected) between the two years (2012 compared with 2013). Mean polyp detection rate was correlated with mean withdrawal time for each endoscopist.
Individual performance data from the first year was discussed at an audit meeting (allowing comparison with other endoscopists and international literature).
HYPERPLASTIC
SESSILE SERRATED
ADENOMA
RESULTS
Data was collected on 5046 procedures.
The crude polyp detection rate 57% (range 32 to 79%).
Adenoma detection rate 26% (range 15% to 41%).
Hyperplastic polyps detection rate 29% (range 13% to 36%).
Sessile serrated polyp detection rate 7% (range 3% to 12%).
For adenomas, hyperplastic polyps and sessile serrated polyps there were significant differences in detection rates between endoscopists after adjusting for age and sex ( p< for all types of polyps).
Polyp detection rate increased from 54.0% to 60.3% from 2012 to 2013.
Adenoma detection rate increased from 26.5% to 32.2%.
For patients > 50 years the change in adenoma detection rate was 27.7% to 33.3%; all p<
Serrated polyp detection rate did not change (7.3% cf. 7.4%). (additional data from 2014 shows this rate to have improved to 12%).
Adenoma detection rate increased in 6 endoscopists.
The mean withdrawal time increased for all 6.
Adenoma detection rates was reduced for 3 endoscopists.
The mean withdrawal time was decreased for all 3.
CONCLUSION
For each endoscopist, the mean detection rate for adenomas, serrated polyps and hyperplastic polyps is closely correlated with mean withdrawal time.
Feedback on histology through the audit process appears to provide experienced endoscopists with more incentive to improve polyp detection.
There were significant increases in adenoma detection rates for all six endoscopists who increased their withdrawal times.
Presentation of results with comparison to other endoscopists and to international literature is likely to be an important motivating factor for improved polyp detection.
The key behavioral change may be an increase in withdrawal time but participation in an audit is also likely to increase vigilance for polyp detection.
Future studies are planned assessing the value of the number of adenomas and sessile serrated polyps for the audit process.