PT - JOURNAL ARTICLE AU - Suarthana, Eva AU - Moons, Karel G M AU - Heederik, Dick AU - Meijer, Evert TI - A simple diagnostic model for ruling out pneumoconiosis among construction workers AID - 10.1136/oem.2006.027904 DP - 2007 Sep 01 TA - Occupational and Environmental Medicine PG - 595--601 VI - 64 IP - 9 4099 - http://oem.bmj.com/content/64/9/595.short 4100 - http://oem.bmj.com/content/64/9/595.full SO - Occup Environ Med2007 Sep 01; 64 AB - Background: Construction workers exposed to silica-containing dust are at risk of developing silicosis even at low exposure levels. Health surveillance among these workers is commonly advised but the exact diagnostic work-up is not specified and therefore may result in unnecessary chest x ray investigations. Aim: To develop a simple diagnostic model to estimate the probability of an individual worker having pneumoconiosis from questionnaire and spirometry results, in order to accurately rule out workers without pneumoconiosis. Methods: The study was performed using cross-sectional data of 1291 Dutch natural stone and construction workers with potentially high quartz dust exposure. A multivariable logistic regression model was developed using chest x ray with ILO profusion category ⩾1/1 as the reference standard. The model’s calibration was evaluated with the Hosmer–Lemeshow test; the discriminative ability was determined by calculating the area under the receiver operating characteristic curve (ROC area). Internal validity of the final model was assessed by a bootstrapping procedure. For clinical application, the diagnostic model was transformed into an easy-to-use score chart. Results: Age 40 years or older, current smoker, high-exposure job, working 15 years or longer in the construction industry, “feeling unhealthy” and FEV1 were independent predictors in the diagnostic model. The model showed good calibration (a non-significant Hosmer–Lemeshow test) and discriminative ability (ROC area 0.81, 95% CI 0.74 to 0.85). Internal validity was reasonable; the optimism corrected ROC area was 0.76. By using a cut-off point with a high negative predictive value the occupational physician can efficiently detect a large proportion of workers with a low probability of having pneumoconiosis and exclude them from unnecessary x ray investigations. Conclusions: This diagnostic model is an efficient and effective instrument to rule out pneumoconiosis among construction workers. Its use in health surveillance among these workers can reduce the number of redundant x ray investigations.