BackgroundMany patients and healthcare professionals believe that workârelated psychosocial stress, such as job strain, can make asthma worse, but this is not corroborated by empirical evidence. We investigated the associations between job strain and the incidence of severe asthma exacerbations in workingâage European men and women.MethodsWe analysed individualâlevel data, collected between 1985 and 2010, from 102 175 workingâage men and women in 11 prospective European studies. Job strain (a combination of high demands and low control at work) was selfâreported at baseline. Incident severe asthma exacerbations were ascertained from national hospitalization and death registries. Associations between job strain and asthma exacerbations were modelled using Cox regression and the studyâspecific findings combined using randomâeffects metaâanalyses.ResultsDuring a median followâup of 10Â years, 1 109 individuals experienced a severe asthma exacerbation (430 with asthma as the primary diagnostic code). In the ageâ and sexâadjusted analyses, job strain was associated with an increased risk of severe asthma exacerbations defined using the primary diagnostic code (hazard ratio, HR: 1.27, 95% confidence interval, CI: 1.00, 1.61). This association attenuated towards the null after adjustment for potential confounders (HR: 1.22, 95% CI: 0.96, 1.55). No association was observed in the analyses with asthma defined using any diagnostic code (HR: 1.01, 95% CI: 0.86, 1.19).ConclusionsOur findings suggest that job strain is probably not an important risk factor for severe asthma exacerbations leading to hospitalization or death.