@article {Hedman00074-2022, author = {Linn{\'e}a Hedman and Linn{\'e}a Almqvist and Anders Bjerg and Martin Andersson and Helena Backman and Matthew S. Perzanowski and Eva R{\"o}nmark}, title = {Early-life risk factors for development of asthma from 8 to 28 years of age {\textendash} a prospective cohort study}, elocation-id = {00074-2022}, year = {2022}, doi = {10.1183/23120541.00074-2022}, publisher = {European Respiratory Society}, abstract = {Aim To estimate the incidence rate of asthma from age 8 to 28 years and evaluate early-life risk factors for asthma onset at different ages.Methods In 1996, within the Obstructive Lung disease In Northern Sweden studies, a cohort of 3430 schoolchildren (97\% of invited) was recruited at age 8 years to a prospective study about asthma. The cohort was followed annually from 8{\textendash}19 years and at 28 years by questionnaire surveys (67\% of the original cohort participated). Asthma was categorised as never asthma, onset <=8 years, 9{\textendash}13 years, 14{\textendash}19 years, or \>19 years.Results Of 3430 individuals in the cohort, 690 (20.1\%) reported asthma in any survey. The average incidence was 10.0/1000 per year <=8 years, 11.9/1000/year from 9 to 13 years, 13.3/1000/year from 14 to 19 years, and 6.1/1000/year \>19 years. The incidence was higher among boys until age 10y, but from age 15y, it became higher among girls. Family history of asthma, allergic sensitisation, and breastfeeding \<3 months were associated with asthma onset throughout the study. Low birthweight, maternal smoking during pregnancy, severe respiratory infection, rhinoconjunctivitis and eczema were associated with asthma onset <=8 years and 9 to 13 years.Conclusions The incidence of asthma was high during childhood and the teenage period and decreased substantially during young adulthood. Early life factors were associated with asthma onset throughout childhood but had also a lasting effect on asthma incidence until adulthood.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: Helena Backman has received payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Astra Zeneca and Boehringer Ingelheim, outside the submitted work.Conflict of interest: The remaining authors have nothing to disclose.}, URL = {https://openres.ersjournals.com/content/early/2022/06/16/23120541.00074-2022}, eprint = {https://openres.ersjournals.com/content/early/2022/06/16/23120541.00074-2022.full.pdf}, journal = {ERJ Open Research} }