Inter- and intra-observer variability of the Los Angeles classification: a reassessment.
BACKGROUND
Los Angeles classification is widely adopted for reporting endoscopic gastroesophageal reflux disease. We assessed the inter- and intra-observer variability of the Los Angeles classification.


METHODS
Still images (n = 254) of the lower esophagus were presented to 9 gastroenterologists (6 experts and 3 trainees) and they were asked to report the images according to the Los Angeles classification. After 2 weeks the images were reordered and they were asked to report them again. Kappa statistic was calculated for intra- and inter-observer variability.


RESULTS
The kappa for intra-observer agreement was 0.54 (attendings: 0.54; trainees; 0.55; P = not significant) and the inter-observer agreement was 0.22 (attendings: 0.20; trainees: 0.31; P = 0.027). The inter- and intra-observer kappa values in differentiating nonerosive from erosive cases were 0.22 (attendings: 0.21; trainees: 0.31, P = not significant) and 0.57 (attendings: 0.58; trainees: 0.55, P = not significant), respectively.


CONCLUSIONS
According to our data, the Los Angeles classification has acceptable intra-observer variability, both for detecting presence or absence of erosions and for differentiating between different degrees of esophagitis, while its inter-observer performance seems to be less acceptable. It may be reasonable and timely to have another look at the Los Angeles classification to see whether its performance can be improved even further.
Nasseri-Moghaddam
Siavosh
S
Digestive Disease Research Center (DDRC), Tehran University of Medical Sciences Tehran, Iran. sianm@ams.ac.ir.
Razjouyan
Hadi
H
Nouraei
Mehdi
M
Alimohammadi
Maysam
M
Mamarabadi
Mansoureh
M
Vahedi
Homayoon
H
Pourshams
Akram
A
Mohamadnejad
Mehdi
M
Zamani
Farhad
F
Sadr
Farhad
F
Darvish-Moghaddam
Sodaif
S
Farsi
Pantea
P
Malekzadeh
Reza
R
D003937:Diagnosis, Differential; D016099:Endoscopy, Gastrointestinal / Q000706:statistics & numerical data*; D005764:Gastroesophageal Reflux / Q000145:classification* / Q000175:diagnosis; D006801:Humans; D015141:Los Angeles; D015588:Observer Variation