Inter-reader variability in chest radiography and HRCT for the early detection of asbestos-related lung and pleural abnormalities in a cohort of 636 asbestos-exposed subjects.
OBJECTIVE
To compare inter-reader variability of chest X-ray and high resolution computed tomography (HRCT) scans of formerly asbestos-exposed employees over a 4-year period.


METHODS
In this longitudinal study, 636 formerly asbestos-exposed persons were annually examined with chest radiographs and HRCT scans. Ten observer pairs classified the radiographs and HRCT scans, using the ILO classification and a custom-made CT classification. Inter-observer variability was calculated using the kappa-coefficient.


RESULTS
Despite all expectations, HRCT inter-reader variability according to asbestos-related lung or pleura alterations at an early stage did not turn out to be better than X-ray inter-reader variability. Substantial inter-observer agreement was found for pleural calcifications (kappa(X-ray) = 0.63; kappa(CT) = 0.64). Averaging over kappa led to fair inter-observer agreement of both methods (kappa(X-ray) = 0.36; kappa(CT) = 0.34).


CONCLUSIONS
High resolution computed tomography scans are superior to X-rays in detecting lung alterations after asbestos exposure and are supposedly easier to interpret. Nevertheless, inter-observer variability did not differ between the two methods in this study. This was probably due to the only discrete asbestos-related lung or pleura alterations of this cohort and to the unfamiliar CT classification sheet, which was revised on the basis of the presented results.
Ochsmann
Elke
E
Institute of Occupational and Social Medicine, Medical Faculty, RWTH-Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany. eochsmann@ukaachen.de
Carl
Tanja
T
Brand
Peter
P
Raithel
Hans-Jürgen
HJ
Kraus
Thomas
T
D000368:Aged; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D001194:Asbestos / Q000633:toxicity*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D016273:Occupational Exposure / Q000009:adverse effects*; D010994:Pleura / Q000000981:diagnostic imaging* / Q000473:pathology; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D000395:Air Pollutants, Occupational; D001194:Asbestos