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

Abstract

Objective: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.Methods: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.Results:Of 31 workers with RCS-related CT abnormalities, 25 were classified as silicosis. Fixed cutoff predicted values (FCO) for FEV1 and FVC of <80% and FEV1/FVC of <0.7, FEV1% predicted decline >15%, and FEV1 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 (AUCROC = 0.84).Conclusions:To identify RCS-exposed workers requiring diagnostic referral, priority should be given to those with FCO, PPM, and annual FEV1 decline abnormalities.