Pneumoconiosis combined with connective tissue disease in China: a cross-sectional study

ObjectiveTo describe the prevalence, clinical features and potential risk factors of pneumoconiosis in combination with connective tissue disease (CTD) or positive autoantibodies.DesignCross-sectional study.SettingA retrospective study of adults recruited in China between December 2016 and November 2021.ParticipantsA total of 931 patients with pneumoconiosis at Beijing Chao-Yang Hospital were enrolled in this study; of these, 580 patients were included in the final analysis.Main outcome measuresPneumoconiosis combined with CTD or positive autoantibodies was a major adverse outcome.ResultsIn total, 13.8% (80/580) of the patients had combined pneumoconiosis with CTD, among whom the prevalence of CTD was 18.3% (46/251) in asbestosis and 11.4% (34/298) in silicosis/coal mine workers’ pneumoconiosis. In comparison to the general Chinese adult population, the relative risk of various CTD in pneumoconiosis, including rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, primary Sjögren’s syndrome, idiopathic inflammatory myopathy and antineutrophil cytoplasmic antibodies-associated vasculitis, were 11.85, 12.12, 127.40, 4.23, 9.94 and 644.66, respectively. Multivariate analysis revealed that female sex (OR 2.55, 95% CI 1.56 to 4.17) and a later stage of pneumoconiosis (OR 2.04, 95% CI 1.24 to 3.34) were the independent risk factors for CTD in patients with pneumoconiosis (all p