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Occup Environ Med. 2019 Jul;76(7):495-501. doi: 10.1136/oemed-2018-105593. Epub 2019 Apr 20.

Novel clinical scores for occupational asthma due to exposure to high-molecular-weight agents.

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Centre de Recherche, Hôpital du Sacré-Coeur de Montréal, Montreal, Quebec, Canada.
Service de pneumologie, Institute for Work and Health, Epalinges-Lausanne, Switzerland.
Department of Social and Preventive Medicine, School of Public Health, Université de Montréal, Montreal, Quebec, Canada.
Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec, Canada.



Specific inhalation challenge (SIC) as the reference diagnostic test for occupational asthma (OA) is not widely available worldwide. We aimed to develop non-SIC-based models for OA.


Of 427 workers who were exposed to high-molecular-weight agents and referred to OA clinic at Montréal Sacré-Cœur Hospital between 1983 and 2016, we analysed 160 workers who completed non-specific bronchial hyper-responsiveness (NSBHR) tests and still worked 1 month before SIC. OA was defined as positive SIC. Logistic regression models were developed. The accuracy of the models was quantified using calibration and discrimination measures. Their internal validity was evaluated with bootstrapping procedures. The final models were translated into clinical scores and stratified into probability groups.


The final model, which included age ≤40 years, rhinoconjunctivitis, inhaled corticosteroid use, agent type, NSBHR, and work-specific sensitisation had a reasonable internal validity. The area under the receiver operating characteristics curve (AUC) was 0.91 (95% CI 0.86 to 0.95), statistically significantly higher than the combination of positive NSBHR and work-specific sensitisation (AUC=0.84). The top 70% of the clinical scores (ie, the high probability group) showed a significantly higher sensitivity (96.4%vs86.9%) and negative predictive value (93.6%vs84.1%) than the combination of positive NSBHR and work-specific sensitisation (p value <0.001).


We developed novel scores for OA induced by high-molecular-weight agents with excellent discrimination. It could be helpful for secondary-care physicians who have access to pulmonary function test and allergy testing in identifying subjects at a high risk of having OA and in deciding on appropriate referral to a tertiary centre.


asthma; clinical scores; diagnostic model; logistic regression; occupational sensitizers


Conflict of interest statement

Competing interests: CL has received consultancy fees from GlaxoSmithKline Inc (Canada), AstraZeneca Canada, Teva Canada Innovation and Merck Canada Inc; research support from GlaxoSmithKline Inc (Canada); lecture fees from AstraZeneca Canada and Merck Canada Inc; and royalties from UpToDate. AC has received research support from Merck Canada Inc and AstraZeneca Canada; lecture fees from Merck Canada Inc; and royalties from UpToDate. GM has received research support from AstraZeneca Canada and lecture fees from Boehringer-Ingelheim. The rest of the authors declare that they have no relevant conflicts of interest.

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