The National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK) Inflammatory Bowel Disease (IBD) Genetics Consortium collects DNA and phenotypic data from IBD subjects to provide a resource for genetic studies.
No previous studies have been performed on the reliability and validity of phenotypic determinations in either Crohn's disease or ulcerative colitis using primary records.
Dr Hillary Steinhart and colleagues from Canada determined the reliability and validity of these phenotypic assessments.
The de-identified records of 30 IBD patients were reviewed by 2 phenotypers per center using a standard protocol for phenotypic assessment.
Each phenotyper evaluated 10 charts on 2 occasions 5 months apart.
Reliability was expressed as the kappa statistic.
|Area under the receiver of operating curves was more than 0.84 for diagnosis|
|Inflammatory Bowel Diseases|
The investigative team determined performance characteristics by comparison to a consensus-derived gold standard.
The team also generated receiver operating characteristic curves.
The investigators reported that agreement for diagnosis was excellent.
Agreement for Crohn's disease location was good for jejunal, ileal, colorectal, and perianal disease with between 0.6 and 0.7.
The team noted that agreement for Crohn's disease location was fair for esophagogastroduodenal disease at 0.4.
Agreement for ulcerative colitis extent, and Crohn's disease behavior were very good.
The investigators noted that area under the receiver of operating curves was greater than 0.84 for diagnosis, Crohn's disease behavior, ulcerative colitis extent, and ileal and colonic Crohn's disease location.
Dr Steinhart's team commented, "IBD phenotype classification using a standard protocol exhibited very good to excellent inter- and intrarater agreement and validity."
"This study highlights the importance of standard protocols in generating reliable and valid phenotypic assessments."
"The data will facilitate estimates of phenotyping misclassification rates that should be considered when making inferences from IBD genotype-phenotype studies."