Colonoscopy yields fewer polyps as the day progresses despite using social influence theory to reverse the trend.
BACKGROUND
We previously reported that fewer polyps are detected by colonoscopy as the day progresses, a phenomenon that could be modified with "social influence theory" by using auditing and feedback.


OBJECTIVE
To measure the impact of a social influence informational poster on the relationship between time of day and colonoscopy yield.


METHODS
Controlled before-and-after study comparing the polyp yield and time of day relationship in a historical cohort versus a 3-month intervention period.


METHODS
University-based Veterans Affairs medical center.


METHODS
Patients undergoing outpatient screening, surveillance, or diagnostic colonoscopies.


METHODS
Placement of informational posters in endoscopy rooms within view of operators and nurses. The poster depicted a bar graph of the previously documented hour-by-hour decreases in polyp yield coupled with prominent text: "What Time Is It Now?"


METHODS
Polyp yield, including secondary end point limited to adenoma detection. We performed regression to measure the effect of start time on polyp yield.


RESULTS
There were 477 and 301 patients in the control and intervention periods, respectively. There was a negative relationship between start time and polyp yield, including adenoma detection, for both periods (P = .001). Start time remained negatively predictive of polyp and adenoma yield after adjusting for poster exposure and confounders (P = .01).


CONCLUSIONS
Nonrandomized study design.


CONCLUSIONS
An informational poster did not alter the relationship between colonoscopy start time and polyp yield. This strengthens the previous finding that start time may affect polyp yield and suggests that passive use of social influence theory is inadequate to modify this effect. Shortening endoscopy shifts and active auditing with feedback may be necessary.
Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA.
Marc
M
Kaneshiro
Andrew
A
Ho
Michael
M
Chan
Hartley
H
Cohen
Brennan M R
BM
Spiegel
D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology*; D000368:Aged; D002940:Circadian Rhythm; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D003111:Colonic Polyps / Q000175:diagnosis* / Q000453:epidemiology*; D003113:Colonoscopy / Q000193:education / Q000706:statistics & numerical data*; D017598:Efficiency, Organizational / Q000706:statistics & numerical data*; D005246:Feedback; D005260:Female; D006787:Hospitals, Veterans; D006801:Humans; D007396:Internship and Residency; D015141:Los Angeles; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D008485:Medical Audit; D008875:Middle Aged; D057175:Posters as Topic; D014940:Work Schedule Tolerance