CC BY-NC-ND 4.0 · Endosc Int Open 2023; 11(09): E908-E919
DOI: 10.1055/a-2131-4797
Original article

Measuring the observer (Hawthorne) effect on adenoma detection rates

Mahsa Taghiakbari
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
,
Diana Elena Coman
2   Internal Medicine, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, Canada
,
Mark Takla
3   Faculty of Medicine, University of Montreal Hospital Centre, Montreal, Canada (Ringgold ID: RIN25443)
,
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
,
Mickael Bouin
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
,
Simon Bouchard
4   Gastroenterology, Centre de Recherche de l'Université de Montréal (CHUM), Montreal, Canada
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
,
Eric Deslandres
4   Gastroenterology, Centre de Recherche de l'Université de Montréal (CHUM), Montreal, Canada
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
,
Sacha Sidani
4   Gastroenterology, Centre de Recherche de l'Université de Montréal (CHUM), Montreal, Canada
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
,
1   Gastroenterology, Centre Hospitialier de l'Université de Montréal (CHUM), Montreal, Canada
› Author Affiliations

Abstract

Background and study aims An independent observer can improve procedural quality. We evaluated the impact of the observer (Hawthorne effect) on important quality metrics during colonoscopies.

Patients and Methods In a single-center comparative study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the index group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the reference group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure.

Results We included 327 index individuals and 360 referents in the final analyses. The index group had significantly higher PDRs (62.4% vs. 53.1%, P=0.02) and ADRs (39.4% vs. 28.3%, P=0.002) compared with the reference group. The SLDR and AADR were not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (relative risk [RR] 1.51; 95%, CI 1.05–2.17) and more than twofold (RR 2.17; 95%, CI 1.05–4.47) more likely to be higher in the index group than in the reference group.

Conclusions The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in practice.

Supporting information



Publication History

Received: 05 November 2022

Accepted after revision: 13 July 2023

Accepted Manuscript online:
17 July 2023

Article published online:
06 October 2023

© 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

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