The International Severe Asthma Registry is a global initiative looking to ensure that the care of people with severe asthma will continue to improve by collecting detailed information about the health and treatment of as many people with the disease as possible. The study will gather anonymized longitudinal real-life data for participants with severe asthma for five years. The purpose of the registry is to track the progress of participants and determine how well they are responding to treatment. Medical research using data from the registry will give the investigators a better understanding of severe asthma and help the investigators develop and improve the care and treatment for severe asthma participants. The Canadian cohort of the registry will collect information from Canadian participants with severe asthma across seven different sites.

Study staff will collect medical information through reviewing participant medical charts and interviewing participants about their health/asthma. The information collected includes birth date, gender, ethnicity, height/weight, body mass index, medical history (smoking history and exacerbation history), current and past asthma related medications, and any recent test results available pertaining to blood work, lung function, allergen skin prick, and imaging. This information will be collected at the baseline visit, and then once a year at a follow up visit, for five years (total of five visits).

Participants will be assigned a unique study number to protect the confidentiality of their personal health care information. All study data will be de-identified and then stored in a secure information management system, hosted at the study sponsor, Optimum Patient Care Global Limited in Cambridge, United Kingdom. Participant identities will always be kept confidential and will not be included in any research that is published. Data collected across the Canadian sites will be used to find ways to improve asthma treatments in Canada, to report on current patterns of managing severe asthma in Canada, to identify different sub-groups of severe asthma, and to carry out various medical research to understand asthma better and develop new treatments.

Research records and health or other source records may be inspected in the presence of the Principal Investigator or by representatives of the University of British Columbia's Clinical Research Ethics Board for the purpose of monitoring the research. No information or records that disclose participants' identities will be published without subject consent, nor will any information or records that disclose participants' identities be removed or released without subject consent unless required by law.

Inclusion Criteria:

• Participants 18 years or older
• Participants receiving treatment according to GINA Step 5 or uncontrolled in GINA Step 4 (uncontrolled is defined as having severe asthma symptoms or frequent exacerbations)

Exclusion Criteria:

-Participants with mild to moderate asthma

The study population will be selected from respirology/pulmonary clinics across Canada. Participants will be identified and recruited by the study investigators and study staff based on their clinical presentation.