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Development of a definition and rules for causal attribution of post-colonoscopy bleeding
Robert J Hilsden1,2, Courtney M Maxwell3, Nauzer Forbes1,2
1Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
Insights
A new standardized definition for post-colonoscopy bleeding (PCB) and its attribution rules were developed. This definition achieved substantial agreement among reviewers, improving colonoscopy quality assessment.
Area of Science:
- Gastroenterology
- Clinical Quality Improvement
- Health Services Research
Background:
- Post-colonoscopy bleeding (PCB) is a critical indicator for colonoscopy quality.
- Standardized data collection for PCB is recommended for colorectal cancer screening and endoscopy quality programs.
Purpose of the Study:
- To develop and validate a standardized definition and attribution rules for post-colonoscopy bleeding (PCB).
- To assess the interrater reliability of the developed definition and rules among endoscopists and non-endoscopists.
Main Methods:
- A standardized definition and attribution rules for PCB were drafted and refined.
- Interrater reliability was assessed using a validation set of 32 bleeding events reviewed by endoscopists and a research assistant.
- The Kappa statistic was employed to measure agreement for both the PCB definition and attribution.
Main Results:
- The developed definition classified 28 of 32 events as PCB.
- Substantial interrater reliability was achieved for the PCB definition (Kappa=0.82) and attribution (Kappa=0.74).
- A non-endoscopist demonstrated high agreement with the definition (100%) and attribution (Kappa=0.95).
Conclusions:
- A standardized definition and attribution rules for PCB can achieve high interrater reliability.
- The developed framework provides a template for data required for PCB event adjudication in quality improvement programs.
Background:
Post-colonoscopy bleeding (PCB) is an important colonoscopy quality indicator that is recommended to be routinely collected by colorectal cancer screening programs and endoscopy quality improvement programs. We created a standardized and reliable definition of PCB and set of rules for attributing the relatedness of PCB to a colonoscopy.
Methods:
PCB events were identified from colonoscopies performed at the Forzani & MacPhail Colon Cancer Screening Centre. Existing definitions and relatedness rules for PCB were reviewed by the authors and a draft definition and set of rules was created. The definition and rules were revised after initial testing was performed using a set of 15 bleeding events. Information available for each event included the original endoscopy report and data abstracted from the emergency or inpatient record by a trained research assistant. A validation set of 32 bleeding events were then reviewed to assess their interrater reliability by having three endoscopists and one research assistant complete independent reviews and three endoscopists complete a consensus review. The Kappa statistic was used to measure interrater reliability.
Results:
The panel classified 28 of 32 events as meeting the definition of PCB and rated 7, 8 and 6 events as definitely, probably and possibly related to the colonoscopy, respectively. The Kappa for the definition of PCB for the three independent reviews was 0.82 (substantial agreement). The Kappa for the attribution of the PCB to the colonoscopy by the three endosocopists was 0.74 (substantial agreement). The research assistant had a high agreement with the panel for both the definition (100% agreement) and application of the causal criteria (kappa 0.95).
Conclusions:
A standardized definition of PCB and attribution rules achieved high interrater reliability by endoscopists and a non-endoscopist and provides a template of required data for event adjudication by screening and quality improvement programs.
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