The study was conducted by Maritta S. Jaakkola, MD, DSc, of the University of Birmingham and the Finnish Institute of Occupational Health and colleagues. They studied in the Pirkanmaa District in southern Finland with 485 cases of adult-onset asthma and 665 controls. Asthmatics ages 21 to 63 who were diagnosed six months to two years previously participated in the study. Questionnaire asking for information such as personal characteristics and work environment to whether or not they smoked had to be answered by the patients.
Results from the study give valuable insight into why some adults may develop asthma and offer ways to reduce the risk of developing adult-onset asthma: they are avoid allergens, avoid mites and molds, avoid allergens like pets and other domestic animals, mites and molds that are often caused by indoor dampness problems.