Elsevier

Gastrointestinal Endoscopy

Volume 72, Issue 6, December 2010, Pages 1233-1240
Gastrointestinal Endoscopy

Original Article: Clinical Endoscopy
Colonoscopy yields fewer polyps as the day progresses despite using social influence theory to reverse the trend

Presented at the American Gastroenterology Association Health Services Research Symposium, Digestive Disease Week, May 30 to June 4, 2009, Chicago, Illinois.
https://doi.org/10.1016/j.gie.2010.08.034Get rights and content

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.

Design

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

Setting

University-based Veterans Affairs medical center.

Patients

Patients undergoing outpatient screening, surveillance, or diagnostic colonoscopies.

Intervention

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?”

Main Outcome Measurement

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).

Limitations

Nonrandomized study design.

Conclusion

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.

Section snippets

Study design and patients

We performed a controlled before-and-after study in 2 patient groups undergoing outpatient screening, surveillance, or nonurgent diagnostic colonoscopy in the GI procedure unit of the West Los Angeles VA Medical Center: (1) a cohort scheduled for colonoscopy during a baseline period in 2007, and (2) a cohort scheduled for colonoscopy during a 3-month intervention period in 2008. Both periods began in September to provide distance from the start of the academic year. During the intervention

Patient characteristics and descriptive statistics

After excluding inpatient, emergent, urgent, and repeat colonoscopies, there were 477 and 301 patients in the control and intervention periods, respectively. There were important differences between periods, as shown in Table 1. Patients in the intervention period were less likely to have a personal history of polyps, to have previously undergone colonoscopy, and to have a family history of colon cancer. In addition, patients in the intervention period had worse bowel-preparation quality and

Discussion

Polyp detection with colonoscopy may partly depend on when the study is performed.1, 2, 3 It is possible that fatigue may play a role in detecting fewer polyps later in an endoscopic work shift.1, 2, 3, 5 In the present study, we tested an inexpensive and minimally invasive informational poster, based on the tenets of social influence theory,13 to stabilize the relationship between time of day and polyp yield in our unit. We hypothesized that an informational poster would remind clinicians to

References (28)

  • D.K. Rex et al.

    Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the U.S. Multi-Society Task Force on Colorectal Cancer

    Am J Gastroenterol

    (2002)
  • C.H. Chan MY et al.

    Fewer polyps detected by colonoscopy as the day progresses at a Veteran's Administration teaching hospital

    Clin Gastroenterol Hepatol

    (2009)
  • M.R. Sanaka et al.

    Adenomas are detected more often in morning than in afternoon colonoscopy

    Am J Gastroenterol

    (2009)
  • A. Lee et al.

    Queue position in the day's endoscopic schedule impacts effectiveness of colonoscopy

    Gastroenterol

    (2010)

    • Cited by (0)

    DISCLOSURE: Supported by a Veterans Affairs Merit Award (IIR 08-310) to Dr Spiegel. All authors disclosed no financial relationships relevant to this publication.

    If you would like to chat with an author of this article, you may contact Dr Spiegel at [email protected].

    View full text
    Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.