Diagnosing Barrett's esophagus: reliability of clinical and pathologic diagnoses

Background

The accuracy of a Barrett's esophagus diagnosis is not well studied.

Objective

Our purpose was to evaluate the accuracy of a clinical Barrett's esophagus diagnosis and the reproducibility of an esophageal intestinal metaplasia diagnosis.

Methods

All patients with a Barrett's esophagus diagnosis between 1994 and 2005 were identified by use of International Classification of Disease (ICD) and Systematized Nomenclature of Medicine (SNOMED) coding. Subsets received manual record review (endoscopy/pathology reports), slide review by a referral pathologist (interrater reliability), and 2 blinded reviews by the same pathologist (intrarater reliability).

Setting

An integrated health services delivery system.

Main Outcome Measurements

Accuracy of electronic clinical diagnosis and reproducibility of esophageal intestinal metaplasia diagnosis.

Results

A total of 2470 patients coded with Barrett's esophagus underwent record review; a subgroup (616) received manual pathology slide review. Review confirmed a Barrett's esophagus diagnosis for 1533 (61.9%) patients: 437 of 798 subjects (54.8%) with a SNOMED diagnosis alone, 153 of 671 subjects (26.8%) with an ICD diagnosis alone, and 940 of 1101 subjects (85%) who had both a SNOMED and an ICD diagnosis. The same metaplasia diagnosis occurred with 88.3% of subjects (original vs referral pathologist, interrater reliability; κ = .42, 95% CI, 0.34-0.48). The referral pathologist made the same metaplasia diagnosis twice for a given patient for 88.6% of subjects (intrarater reliability, 2 reviews by same pathologist; κ = 0.65, 95% CI, 0.35-0.93).

Limitations

The accuracy of a Barrett's esophagus diagnosis likely represents the minimum number, given the strict criteria.

Conclusions

A community pathologist's diagnosis of esophageal intestinal metaplasia is likely to be confirmed by a referral pathologist. Electronic diagnoses of Barrett's esophagus overestimate the prevalence, although they are usually confirmed in patients with both a SNOMED and ICD diagnosis of Barrett's esophagus.

Abbreviations: H&E, hematoxylin and eosin, ICD, International Classification of Disease, KPNC, Kaiser Permanente, Northern California, SNOMED, systematized nomenclature of medicine coding