Chest HRCT signs predict deaths in long-term follow-up among asbestos exposed workers

Abstract

Objectives: To study associations between chest HRCT signs and subsequent deaths in long-term follow-up.

Methods: Lung and pleural signs of 633 asbestos exposed workers (age 45-86, mean 65) screened with HRCT were recorded by using the International Classification of Occupational and Environmental Respiratory Diseases (ICOERD) system, which contains detailed instructions for use and reference images. Subsequent mortality was checked from the national register. Cox regression adjusted for covariates (age, sex, BMI, asbestos exposure, pack-years) was used to explore the relations between HRCT signs and all-cause deaths, cardiovascular and benign respiratory deaths, and deaths from neoplasms - all according to the ICD-10 diagnostic system.

Results: The follow-up totalled 5271.9 person-years (mean 8.3 y/person, range .04-10.3). 119 deaths were reported. Irregular/linear opacities, honeycombing, emphysema, large opacities, visceral pleural abnormalities and bronchial wall thickening were all significantly related to all-cause deaths. Most of these signs were associated also with deaths from neoplasms and benign respiratory disease. Deaths from cardiovascular disease were predicted by emphysema and visceral pleural abnormalities.

Conclusions: Several HRCT signs predicted deaths. Careful attention should be paid on subjects with radiological signs predictive of deaths and new secondary preventive strategies developed. This calls for further focused studies among different populations.

Keywords: Classification; Follow-up studies; Lung diseases; Mortality; Tomography; X-ray computed.