Follow-up of asbestosis patients and predictors for radiographic progression

• Published in: International archives of occupational and environmental health 1998-10, Vol.71 (7), p.465-471
• Main Authors: OKSA, P, HUUSKONEN, M. S, JÄRVISALO, J, KLOCKARS, M, ZITTING, A, SUORANTA, H, TOSSAVAINEN, A, VATTULAINEN, K, LAIPPALA, P
• Format: Article
• Language: English
• Subjects: Adult; Aged; Asbestosis - blood; Asbestosis - diagnostic imaging; Asbestosis - pathology; Biological and medical sciences; Blood Sedimentation; Chemical and industrial products toxicology. Toxic occupational diseases; Disease Progression; Female; Fibronectins - blood; Follow-Up Studies; Humans; Inorganic dusts (pneumoconiosises) and organic dusts (byssinosis etc.); Logistic Models; Male; Medical sciences; Middle Aged; Odds Ratio; Peptidyl-Dipeptidase A - blood; Predictive Value of Tests; Radiography; Reproducibility of Results; Risk Factors; Toxicology
• ISSN: 0340-0131; 1432-1246
• DOI: 10.1007/s004200050307

We followed a group of 85 Finnish asbestosis patients radiographically for an average of 6.5 (range 2-10) years to examine the progression of the disease and to assess possible explanations for the progression. The examinations included full-size chest radiographs and a blood specimen analysis. The radiographs were classified according to the 1980 International Labor Office (ILO) classification. Progression was accepted if the second or third radiography was estimated (in a side-by-side comparison) to have more profusion of small opacities qualitatively than the first, even if the radiographs were classified into the same profusion category. In all, 38% of the patients showed progression during the follow-up period. The average progression of small opacities ranged from ILO 1/1 to ILO 2/2 (0.4 minor ILO categories/year). The asbestosis was progressive more often among the sprayers than among the insulators and asbestos factory workers [cross-tabulation, odds ratio (OR) 5.0, 95% confidence interval (95% CI) 1.2-20]. In the logistic regression model the ILO classification category at the beginning of the follow-up (OR 1.54; 95% CI 0.96-2.47), the fibronectin (OR 1.01; 95% CI 1.00-1.01) and angiotensin-converting enzyme (ACE; OR 1.10; 95% CI 1.00-1.20) levels, and the erythrocyte sedimentation rate (ESR; OR 1.05; 95% CI 1.00-1.10) were statistically associated with the radiographic progression of small opacities. Abnormalities of the pleura were found to progress more often among the patients with progressive parenchymal opacities. For the progression of small-opacity profusion the significant predictors in the logistic regression model were the ILO profusion category at the beginning of the follow-up period, the fibronectin level, the ACE value, and the ESR. The model correctly classified 94% of the patients with progression and 65% of those without progression. The differences in the mean values recorded for the biomarkers between the progressors and nonprogressors, however, were small and may therefore not be of any importance to the clinician.