Association of preserved ratio impaired spirometry with mortality and airflow obstruction in the silicotics: A longitudinal cohort study

This longitudinal cohort study evaluated the association between PRISm and the risk of mortality and incident airflow obstruction in 4315 workers with silicosis in Hong Kong, China. Lung function testing (FEV1, FVC, FEV1/FVC ratio) was undertaken at diagnosis and at follow-up reassessments using a Vitalograph wedge bellows spirometer.