The Diagnostic Value of Routine Spirometry in Occupational Health Practice for Early Detection of Silicosis: A Retrospective Belgian Study Among Silica-Exposed Workers.

Abstract

Silicosis is a pneumoconiosis caused by respirable crystalline silica (RCS). As current surveillance methods have low sensitivity for early detection, we evaluated the value of prediagnostic occupational spirometry monitoring. To investigate the possibility of detecting disease, we assessed 58 RCS-exposed cases by linking lung function abnormalities to CT readings. Univariate, stepwise logistic regression and ROC analysis were performed. Of 31 workers with RCS-related CT abnormalities, 25 were classified as silicosis. Fixed cutoff predicted values (FCO) for FEV 1 and FVC of <80% and FEV 1 /FVC of <0.7, FEV 1 % predicted decline >15%, and FEV 1 decline >60 mL/year were significantly associated with pathological outcome. Combining FCO ( P  = 0.001) and percentage predicted method (PPM) ( P  = 0.023) best predicted silicosis (AUC ROC  = 0.84). To identify RCS-exposed workers requiring diagnostic referral, priority should be given to those with FCO, PPM, and annual FEV 1 decline abnormalities.