A Prognostic Model Of Excessive Lung Function Decline Among Quebec Apprentices: A Cohort Exposed To Occupational Sensitizing Agents

BACKGROUND Forced expiratory volume in 1 second (FEV 1) decline as a predictor of lung-related health problems is widely observed, but not fully investigated. This study aimed to develop models to predict FEV 1 decline among apprentices exposed to sensitizing agents.METHODS Of 692 apprentices recruited and followed in 3.6-17.3 years, 292 were exposed to low-molecular-weight agents. The analysis was restricted to 357 apprentices with complete lung function assessment at the end of their training with a minimum of 5-year follow-up. According to the American Thoracic Society guideline, a mean FEV1 decline >60 ml/year was defined as "accelerated." Descriptive statistics and Cox regression analysis were utilized to determine its predictors. To develop the prognostic models, we used a logistic regression analysis adjusted for the follow-up duration. The accuracy of the models was quantified using calibration and discrimination measures.RESULTS Of 357 subjects, 62 (17.4%) had an excessive FEV 1 decline post-apprenticeship. The questionnaire model (model 1), which included male sex, wheezing, and exposure to isocyanate or animal allergens during the apprenticeship, showed a reasonable discriminative ability (area under the receiver operating characteristics curve [AUC] of 0.67, 95% CI = 0.59-0.75). Adding the percent-predicted FEV1 value at the end of apprenticeship significantly increased the discriminative ability of the model (model 4) (AUC = 0.762, 95% CI = 0.694-0.829) with a good calibration and reasonable internal validity.CONCLUSIONS We developed a model for accelerated lung function decline with a good accuracy and internal validity. However, external validation of the model is necessary.