Reflux Esophagitis: Assessment of Therapy Effects and Observer Variation by Video Documentation of Endoscopy Findings

Abstract

Twenty-eight patients with endoscopically confirmed erosive or ulcerative esophagitis completed an 8-week placebo-controlled trial evaluating the symptomatic and endoscopic improvement obtained with ranitidine, 150 mg twice daily. Twice daily the patients recorded the number of episodes of retrosternal pain, regurgitation, and pyrosis on a diary card during a trial period of 1 week and during the 1st and 5th study week. Video documentation of endoscopy findings was undertaken before and at the end of the trial. The symptomatic relief obtained with ranitidine was significantly better than that obtained with placebo. The videotapes were assessed blindly and independently by three experienced fiberoptic endoscopists. The tapes were also recoded and reassessed by the same endoscopist. No systematic difference between different observers, either before or after treatment, could be detected. The interobserver variation, expressed as Kendall's τ_b correlation coefficient, was 0.44 to 0.74. This coefficient was higher in intra-observer variation (0.63 to 0.91). Corresponding k-values for inter- and intra-observer variations were 0.12 to 0.30 and 0.27 to 0.85, respectively. The esophagitis, as judged by all observers, improved more in the ranitidine group than in the placebo group, but the difference did not reach statistical significance.

Key Words:

• Endoscopy
• observer bias
• observer variation
• ranitidine
• reflux esophagitis