Interobserver Variation in the Endoscopic Diagnosis of Reflux Esophagitis

Abstract

The interobserver variation among three experienced endoscopists in the endoscopic diagnosis and grading of reflux esophagitis was investigated in 150 dyspeptic patients. The interobserver variation was analyzed with kappa statistics to correct for the extent of agreement expected by chance alone. The observers diagnosed esophagitis in 22.7%, 32.7%, and 35.3% of the patients, respectively (p < 0.0002). Kappa values for grade-1 esophagitis varied from 0.34 to 0.47, a level generally considered to signify poor agreement, and despite partial agreement on the diagnosis in the individual patient there was almost complete disagreement on the features used to characterize grade 1. Kappa values for diagnosing erosive esophagitis (grades 2-4) were 0.68-0.79. Considering all three observers and all grades of esophagitis (grades 0-4) the overall chance-corrected agreement was 0.55. In patients with low-grade esophagitis without reflux-like dyspepsia and when the observers expressed uncertainty in the diagnosis, the agreement rates were particularly poor. Due to a large chance-corrected interobserver variation, the endoscopic diagnosis grade 1 esophagitis is not reliable and thus may be problematic as a selection criterion for clinical trials. Interobserver variation on the presence of erosive/ulcerative esophagitis is acceptable and comparable to the level for peptic ulcer.

Los Angeles Classification of Esophagitis using Image Processing Techniques

“…Statistical, DCT and DWT parameters have good overall efficiency in the range of 74% to 76% compared to HSI parameters. The kappa values vary between 0.683 to 0.6 LA Classification by presenting images and video to experts and trainee gastroenterologists has been reported in [17][18][19][20][21][22]. The kappa for intra-observer agreement was 0.54 and interobserver agreement was 0.22 reported by [17].…”

Variations in the reporting of endoscopies by different endoscopists

“…Some studies have been 'head to head' comparisons of expert endoscopists, involving small numbers of consecutive procedures on the same patient. 13 Alternatively, some groups have investigated interobserver agreement using still photographic images. 11,12,16,17 However, the quality of the stored still images is a significant limitation and resolution is often suboptimal.…”

“…In particular, the degree of oesophagitis has been investigated by several authors. [11][12][13]16,18 In published studies, kappa values are often below 0.4, signifying poor interobserver agreement. This is often the case with inexperienced endoscopists, 11,12 and for more minor degrees of oesophagitis.…”

“…This is often the case with inexperienced endoscopists, 11,12 and for more minor degrees of oesophagitis. 13 Agreement on the complications of oesophagitis (stricture and ulceration) is better. 11,13 In addition, intraobserver agreement is often poor, 12 so perhaps it is not surprising that different endoscopists cannot agree.…”

“…9,10 There is little published literature regarding diagnostic consistency among endoscopists. 11,12,13 Some evidence suggests that there may be considerable variability in interpreting endoscopic appearances, with potentially important clinical consequences. 14,15 Many of the published studies concentrate on 'expert' endoscopists looking at relatively small numbers of patients.…”