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

Abstract

ObjectiveSpecific 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.MethodsOf 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.ResultsThe 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).ConclusionsWe 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.

Occupational inhalant allergy in food handling occupations

“…Significant variables included those ≤40 years of age, rhino-conjunctivitis, inhaled corticosteroid use, agent type, nonspecific BHR and occupational-specific sensitization. This is a useful approach for clinics without access to specific inhalation challenge tests [49].…”

The validity of the Canadian clinical scores for occupational asthma in European populations

“…Therefore, Suarthana and colleagues developed non-SIC-based diagnostic models for OA using Quebec data of 160 symptomatic subjects who completed an SIC procedure (ie, development set). 4 These subjects were exposed to high-molecular-weight (HMW) protein agents such as flour, laboratory animal allergens, and latex. OA was defined as a positive SIC, namely a sustained fall in forced expiratory volume in one second (FEV 1 ) >20% from baseline value after exposure to the suspected occupational agent.…”

“…4 Sum scores ≥ 150 with a corresponding predicted probability of OA > 0.25 were recommended for referral cutoff with a sensitivity of 96%, specificity 59%, positive predicted value 72%, and negative predicted value 94%. 4 It is now available as a free app on Calculate by QxMD at: https://qxcalc.app.link/occ-asthma-hmw. In this study, we externally validated this model to evaluate its generalizability so that it could be used in practice with confidence.…”

“…To facilitate its use, it was transformed into clinical scores equipped with the corresponding predicted probability of OA. 4 Sum scores ≥ 150 with a corresponding predicted probability of OA > 0.25 were recommended for referral cutoff with a sensitivity of 96%, specificity 59%, positive predicted value 72%, and negative predicted value 94%. 4 It is now available as a free app on Calculate by QxMD at: https://qxcalc.app.link/occ-asthma-hmw.…”

“…Eva Suarthana 1,2 Mahsa Taghiakbari 1,2 Paramita Saha-Chaudhuri 3 Catherine Rifflart 4 Hille Suojalehto 5 Pirjo Hölttä…”