RT Journal Article SR Electronic T1 Occupation and subcategories of asthma: a population-based incident case–control study JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP oemed-2020-106953 DO 10.1136/oemed-2020-106953 A1 Maritta S Jaakkola A1 Taina K Lajunen A1 Behzad Heibati A1 Ying-Chuan Wang A1 Ching-Huang Lai A1 Jouni J K Jaakkola YR 2021 UL http://oem.bmj.com/content/early/2021/07/18/oemed-2020-106953.abstract AB Background We hypothesised that occupational exposures differently affect subtypes of adult-onset asthma.Objective We investigated potential relations between occupation and three subtypes of adult asthma, namely atopic asthma, non-atopic asthma and asthma–COPD overlap syndrome (ACOS).Methods This is a population-based case–control study of incident asthma among working-age adults living in Pirkanmaa Hospital District in Southern Finland. The determinant of interest was occupation at the time of diagnosis of asthma or the job that the subject had quit due to respiratory symptoms. Asthma was divided into three mutually exclusive subtypes on the basis of any positive IgE antibody (atopic and non-atopic asthma) and presence of persistent airways obstruction in spirometry (ACOS). We applied unconditional logistic regression analysis to estimate adjusted OR (aOR), taking into account gender, age and smoking.Results The following occupational groups showed significantly increased risk of atopic asthma: chemical industry workers (aOR 15.76, 95% CI 2.64 to 94.12), bakers and food processors (aOR 4.69, 95% CI 1.18 to 18.69), waiters (aOR 4.67, 95% CI 1.40 to 15.56) and those unemployed (aOR 3.06, 95% CI 1.52 to 6.17). The following occupations showed clearly increased risk of non-atopic asthma: metal workers (aOR 8.37, 95% CI 3.77 to 18.59) and farmers and other agricultural workers (aOR 2.36, 95% CI 1.10 to 5.06). Some occupational groups showed statistically significantly increased OR of ACOS: electrical and electronic production workers (aOR 30.6, 95% CI 6.10 to 153.35), fur and leather workers (aOR 16.41, 95% CI 1.25 to 215.85) and those retired (aOR 5.55, 95% CI 1.63 to 18.97).Conclusions Our results show that different occupations are associated with different subtypes of adult-onset asthma.Data are available upon reasonable request. The datasets generated and/or analysed during the current study are not publicly available due to issues of confidentiality, but are available from the corresponding author on reasonable request.