Lung function predicts mortality: 10-year follow-up after lung cancer screening among asbestos-exposed workers

Abstract

Purpose: To assess the predictive value of lung function impairment on mortality among asbestos-exposed workers.

Methods: A total of 590 workers originally screened for occupational lung disease including spirometry and pulmonary diffusing capacity measurements were followed up for mortality data (ICD-10 classification). The mean follow-up time was 10.5 years. Associations of different lung function parameters with mortality from all causes and from cardiovascular (I00-I99) and non-malignant respiratory diseases (J00-J99) were analysed. Factor analysis was used to create obstructive and restrictive factors.

Results: A total of 191 deaths were found altogether. Most measured lung function variables were associated with increased mortality when studied separately. Both decreased forced expiratory flow in one second (hazard ratio/measurement unit = 0.977, 95 % CI 0.969-0.988, p < 0.001) and impaired diffusing capacity (0.973, 0.965-0.981, p < 0.001) were independently associated with mortality from all causes, as well as from cardiovascular and non-malignant respiratory diseases. Both obstructive factor alone and the sum of obstructive and restrictive factors were associated with all studied mortality categories. The restrictive factor alone was associated with all-cause and respiratory mortality.

Conclusions: Deteriorated lung function predicts deaths. The reasons for impaired lung function should be medically explored to enable restoring measures aiming thus to prevent premature deaths.