Original Article: Clinical Endoscopy
Intraobserver and interobserver consistency for grading esophagitis with narrow-band imaging

https://doi.org/10.1016/j.gie.2006.10.056Get rights and content

Background

Narrow-band imaging (NBI) is a novel, noninvasive optical technique that adjusts reflected light to enhance the contrast between the esophageal mucosa and the gastric mucosa. Whether the use of this optical technique may increase consistency in describing the presence and severity of mucosal breaks remains elusive.

Objectives

We compared the intra- and interobserver variations in the endoscopic scoring of esophagitis by using conventional imaging with and without NBI.

Design

Cross-sectional study of consecutive patients with reflux.

Setting

Single center in Taiwan.

Patients

Endoscopic photographs of 230 patients with gastroesophageal reflux were obtained with both methods. Images were randomly displayed twice to 7 endoscopists, who independently scored each photograph by using the Los Angeles classification.

Main Outcome Measurements

We calculated intra- and interobserver κ statistics to measure the consistency in interpretations.

Results

With the addition of NBI, intraobserver reproducibility significantly improved with 3 of the 7 endoscopists. Interobserver reproducibility was more consistent with the combined approach than with conventional imaging alone, with an improved overall κ value of 0.62 versus 0.45 (P < .05). Discordance between these methods was substantial in the grading of class A or B esophagitis.

Limitations

A small sample of class D esophagitis might have produced insufficient statistical power in this category.

Conclusions

Intra- and interobserver reproducibilities in grading esophagitis could be improved when NBI was applied with conventional imaging. The benefit appeared to derive from better depictions of small erosive foci.

Section snippets

Patients and design

Between October 2005 and March 2006, we prospectively recruited 230 consecutive subjects with symptoms suggestive of GERD. Participants provided informed consent, and the ethics committee of National Taiwan University Hospital approved the study protocol.

All subjects received conventional endoscopic imaging, as well as imaging with the NBI system by using video endoscopes (GIF-H260; Olympus Optical Co, Ltd, Tokyo, Japan). Four experienced endoscopists performed the examinations (Y.C.L., H.M.C.,

Intraobserver variability

The percentages of photographs graded to each grade of esophagitis, as determined by using the conventional system with or without NBI, are shown in Table 1. The most frequent category was ENRD, followed by esophagitis of classes A, B, C, and D. A significant difference was noted in the distribution of grades between the rating approaches (χ2[4] = 40.63, P < .0001).

Intraobserver κ values for evaluations done without and with NBI are shown in Table 2, Table 3, respectively. With only

Discussion

Videoendoscopy is based on the different abilities of various wavelengths of light to penetrate tissues. The blue band is used for evaluating superficial layers; the green band, for intermediate layers; and the red band, for deep layers. In NBI, the central wavelengths of the dichromatic optical filters are 415 and 540 nm, and each has 30-nm bandwidths. These properties allow enhanced and real-time observation of the microvascular architecture of the superficial mucosa.10 Performed in the usual

Acknowledgments

We thank Jiann-Hwa Chen, MD, Wei-Chih Su, MD, Buddhist Tzu Chi General Hospital, Taipei Branch; Fu-Jen Lee, MD, Taiwan Adventist Hospital; and Chi-Huang Yeh, MD, Xiang-An Clinics, for participating in the assessment of GERD.

References (24)

  • P. Bytzer et al.

    Interobserver variation in the endoscopic diagnosis of reflux esophagitis

    Scand J Gastroenterol

    (1993)
  • W.M. Wong et al.

    Clinical practice pattern of gastroenterologists, primary care physicians, and otolaryngologists for the management of GERD in the Asia-Pacific region: the FAST survey

    J Gastroenterol Hepatol

    (2004)
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