Pulmolines is a group of studies investigating the obstructive airway, pulmonary disease, and ageing. The ATLANTIS cohort within Pulmolines was designed to focus on the prevalence and impact of asthma. ATLANTIS recruited over 700 participants aged 18 to 65 years who had received a clinical asthma diagnosis at least 6 months before recruitment from nine countries (Brazil, Canada, China, Germany, Italy, Spain, the Netherlands, the United Kingdom, and the United States of America). Around 100 participants without asthma were also recruited to serve as a control group. Control participants were also aged 18 to 65 years, from one of the nine recruitment countries and had no symptoms of asthma or chronic obstructive pulmonary disease. Data was collected from 2014, and all participants were followed up at baseline, 6 months, and 12 months.