Inter-reader agreement in HRCT detection of pleural plaques and asbestosis in participants with previous occupational exposure to asbestos

Our plain-English summary of Inter-reader agreement in HRCT detection of pleural plaques and asbestosis in participants with previous occupational exposure to asbestos, by F. Laurent, C. Paris, G.R. Ferretti, et al (Occupational and Environmental Medicine, 2014).

The study

• Authors: F. Laurent, C. Paris, G.R. Ferretti, C. Beigelman, M. Montaudon, V. Latrabe, A. Jankowski, Y. Badachi, B. Clin, A. Gislard, M. Letourneux, A. Luc, E. Schorlé, P. Brochard, J. Ameille, J.C. Pairon
• Journal: Occupational and Environmental Medicine
• Published: 2014;71(12):865-70
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: To investigate inter-reader agreement for the detection of pleural and parenchymal abnormalities using CT in a large cross-sectional study comprising information on individual cumulative exposure to asbestos.

Methods: The project was approved by the hospital ethics committee, and all patients received information on the study and gave their written informed consent. In 5511 CT scans performed in a cohort of retired workers previously exposed to asbestos and volunteering to participate in a multiregional survey programme (Asbestos Related Diseases Cohort, ARDCO), double randomised standardised readings, triple in case of disagreement, were performed by seven trained expert radiologists specialised in thoracic imaging and blind to the initial interpretation. Inter-reader agreement was evaluated by calculating the κ-weighted coefficient between pairs of expert readers and results of routine practice and final diagnosis after expert reading.

Results: κ-Weighted coefficients between trained experts ranged from 0.28 to 0.52 (fair to good), 0.59 to 0.86 (good to excellent) and 0.11 to 0.66 (poor to good) for the diagnosis of asbestosis, pleural plaques and fibrosis of the visceral pleura, respectively. κ-Weighted coefficients between results of routine practice and final diagnosis after expert reading were 0.13 (poor), 0.53 (moderate) and 0.11 (poor) for the diagnosis of asbestosis, pleural plaques and fibrosis of the visceral pleura, respectively.

Conclusions: Interpretation of benign asbestos-related thoracic abnormalities requires standardisation of the reading and trained readers, particularly for participants asking for compensation, and with a view to the longitudinal survey of asbestos-exposed workers.

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

In plain English

This French study measured how consistently radiologists read chest CT scans for asbestos-related disease. It used scans of 5511 retired or unemployed men formerly exposed to asbestos at work, screened in four French regions between 2003 and 2005. Radiologists who were not chest specialists first read the scans in routine practice. Two of seven trained expert chest radiologists then read each scan independently, with a third when they disagreed. Agreement (weighted kappa) between experts ranged from 0.28 to 0.52 (fair to moderate) for asbestosis, 0.59 to 0.86 (moderate to excellent) for pleural plaques, and 0.11 to 0.66 (poor to good) for visceral pleural fibrosis. Agreement between routine and final expert diagnoses was 0.13 (poor; 95% CI 0.08 to 0.17), 0.53 (moderate; 95% CI 0.50 to 0.56) and 0.11 (poor; 95% CI 0.04 to 0.18) for these three conditions. Routine practice identified 335 asbestosis cases; experts confirmed 26 and added 11 more. The authors recommended dedicated training and standardised reading, particularly when medicolegal issues are involved. They noted there was no tissue proof of asbestosis and no control group.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional study of inter-reader agreement on CT scans within a screening programme. Routine readings by qualified radiologists who were not chest radiologists were compared with independent double readings by trained expert chest radiologists, with a third reading when the two disagreed.
• Who was studied: 5511 asbestos-exposed men, retired or unemployed workers previously occupationally exposed to asbestos, in the APEXS screening programme in four regions of France (Aquitaine, Rhône-Alpes, Haute-Normandie and Basse-Normandie), October 2003 to December 2005. Mean age was 63.1 years.
• Exposure: Previous occupational asbestos exposure. Fiber types were not specified. Exposure was assessed by standardised questionnaire as a cumulative exposure index ('exposure units×years') grouped into quintiles. Mean duration of exposure was 31.0 years.
• Main results:
  • Final expert diagnoses: asbestosis in 37 of 4899 participants (0.8%); pleural plaques in 1118 of 5446 (20.5%).
  • Between pairs of trained experts, weighted kappa for asbestosis ranged from 0.28 to 0.52 (fair to moderate).
  • Between pairs of trained experts, weighted kappa for thoracic wall or diaphragmatic pleural plaques ranged from 0.59 to 0.86 (moderate to excellent).
  • Between pairs of trained experts, weighted kappa for fibrosis of the visceral pleura ranged from 0.11 to 0.66 (poor to good).
  • Kappa between routine practice and the final expert diagnosis was 0.13 (95% CI 0.08 to 0.17, poor) for asbestosis, 0.53 (95% CI 0.50 to 0.56, moderate) for pleural plaques and 0.11 (95% CI 0.04 to 0.18, poor) for fibrosis of the visceral pleura.
  • Routine practice identified 335 cases of asbestosis. Expert reading confirmed 26 of them and added 11 cases that routine practice had not identified.
• The authors' conclusion: The authors concluded that agreement on pleural plaques was moderate to excellent between trained experts but lower between experts and the initial reading. They recommended dedicated training and standardised reading methods when medicolegal issues are involved and for studies of the prognostic value of pleural plaques.
• Limitations the authors state:
  • There was no histopathological (tissue) proof of asbestosis.
  • There was no control group.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: High-Resolution CT (HRCT), Pleural Plaques, Occupational Exposure, Cumulative Exposure, Informed Consent, CT Scan, Fibrosis, Visceral Pleura.

Related studies

• Do asbestos-related pleural plaques on HRCT scans cause restrictive impairment in the absence of pulmonary fibrosis? — B. Clin, C. Paris, et al. (2011)
• 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 — E. Ochsmann, T. Carl, et al. (2010)
• Pleural plaques and asbestosis: dose- and time-response relationships based on HRCT data — C. Paris, S. Thierry, et al. (2009)
• Pleural plaques and the risk of pleural mesothelioma — J.C. Pairon, F. Laurent, et al. (2013)
• Asbestos exposure, pleural plaques, and the risk of death from lung cancer — J.C. Pairon, P. Andujar, et al. (2014)
• Asbestos-related cancer risk in patients with asbestosis or pleural plaques — J. Ameille, P. Brochard, et al. (2011)

Browse more research in Occupational and Environmental Medicine, or return to medical research.