Assessing asthma control and severity of work-related asthma cases in the NutriNet-Santé cohort

<b>Background:</b> Over the last decade, attention was provided to better differentiate work-exacerbated asthma (WEA) from occupational asthma (OA). Clinical characteristics are likely to differ between WEA, OA and non work-related asthma (NWRA), however very few data from population-based epidemiological studies are available. <b>Objective:</b> To compare asthma control and severity between WEA and other asthma phenotypes. <b>Methods:</b> This study included 1,015 adults with current asthma (81.7% women, mean age 46.2 years, 541 NWRA cases, 312 WEA cases and 162 OA cases) from the French web-based NutriNet-Santé cohort. Current asthma was defined by lifetime asthma with symptoms or medication use in the past 12 months. Asthma control was assessed by the Asthma Control Test with the following groups: ≤ 19 (poor control), 20-24 (partly controlled asthma) and 25 (complete control), and asthma severity assessment was based on the 2018 Global Initiative for Asthma guidelines. Polytomous logistic regressions adjusted for gender, age, body mass index, smoking status, family history of allergy, educational level and other covariates were used to assess associations. <b>Results:</b> Compared to NWRA cases, OA cases had a significantly increased risk of partly controlled asthma (OR 2.09; 95%CI 1.27-3.44) and both OA cases and WEA cases had a higher risk of poor control (3.98; 2.20-7.19 and 2.52; 1.61-3.96 respectively). Severe asthma was only significantly associated with OA compared to NWRA (2.77; 1.40-5.50). No significant difference were observed between WEA and OA for asthma control or severity. <b>Conclusion:</b> This study suggests that both WEA and OA have poorer asthma control than NWRA and that OA was more severe than NWRA.