An observational study to characterize asthma and severe asthma care and burden across a Canadian population

Summary

Client: Astrazeneca Canada Inc.

Project ID: P2024-219 / 2025 0980 003 000

Research Question/Objectives: Asthma is the third most common chronic disease in Canada, affecting more than 3.8 million Canadians, and worldwide its prevalence has doubled during the past 20 years. Asthma is associated with a significant burden of illness, psychological distress, diminished quality of life and higher healthcare resource utilization (HCRU) and healthcare direct costs. Although sub-types of asthma, such as severe asthma (SA) and eosinophilic asthma (EA), are estimated to make up less than 10% of asthma cases, SA is responsible for approximately 50% of direct healthcare costs. Similarly, SA patients with elevated eosinophils have higher annual hospitalization costs compared to those with normal eosinophil.

Objectives:
Primary objectives:

1. Asthma, SA (for patients 65+), and EA incidence and prevalence will be calculated per calendar year, stratified by regional setting of residence in the year of reporting, and presented as a crude proportion, and age- and sex-standardized rate.
2. For each respiratory-specific and asthma specific healthcare resource*, the following statistics will be reported per calendar year and stratified by regional setting of residence in the year of reporting:
   a. Number of events and number of patients with an event
   b. Crude rate per 1000 person-years
   c. Age-sex standardized rate per 1000 person-years
   d. Crude length of stay (LOS) rate per 1000 person-years and age-sex standardized LOS rate per 1000 person-years (only for hospitalizations)

Secondary objective:

1. Pharmacological treatments for patients aged 65+ stratified by regional setting, will be reported per calendar year and stratified by regional setting of residence in the year of reporting.
   a. Treatment regimens will be considered as monotherapy and combinations when there is at least 14 days of overlap between medication prescriptions.
   b. Treatment patterns will be evaluated as maintenance and non-maintenance treatment. Treatment maintenance will be considered when a patient has been receiving medication for at least 90 days

Status: In Progress