Study type

Study topic

DiseaseĀ /health condition

Study type

Non-interventional study

Scope of the study

Disease epidemiology
Effectiveness study (incl. comparative)

Data collection methods

Secondary use of data
Non-interventional study

Non-interventional study design

Cohort
Study drug and medical condition

Medical condition to be studied

Asthma
Population studied

Short description of the study population

Severe asthma population in the International Severe Asthma Registry who are eligible for both anti-IL-5/5R and antiIgE, based on most frequent eligibility criteria (including those eligible and did not start biologic), at or before the date of initiating of the treatment, overall and per country.

Inclusion criteria:
1. 18 years or older
2. GINA (2018) Step 5 treatment
3. GINA (2018) Step 4 treatment and uncontrolled

Exclusion:
1. Patients who received bronchial thermoplasty

Age groups

Adults (18 to < 46 years)
Adults (46 to < 65 years)
Adults (65 to < 75 years)
Adults (75 to < 85 years)
Adults (85 years and over)

Special population of interest

Other

Special population of interest, other

Asthma patients

Estimated number of subjects

8395
Study design details

Main study objective

The aim is to describe the pattern of use and examine the impact on health outcomes of initiating biologic therapy in a real-world severe asthma population.

Outcomes

To describe and compare the demographic and clinical characteristics between the Anti-IgE and Anti-IL5 users, The two study arms will be balanced using propensity score weighting. Next, using weighted longitudinal regression analysis, the two groups will be compared to describe the health outcomes between the groups such as the rate of exacerbations, OCS use, healthcare resource utilization and lung function, if applicable.

Data analysis plan

The two groups will be identified based on those who initiated and maintained a biologic therapy (anti-lgE, anti-IL5/anti-IL5R, or anti-IL4R) for 6 months ("new biologic users"), and those who stayed on maintenance SCS therapy or used 4 or more courses of SCS bursts (10 mg/day) at the time and were also not on any biologic therapy ("high SCS users"). The two groups will then described and compared based on their demographic and clinical characteristics. Descriptive statistics will be provided for continuous and categorical variables. Summary statistics will be produced for variables measured on the interval or ratio scale, including sample size, mean and SD and categorical variables including range and the percentage by category. After propensity score matching, the two groups will be compared to describe outcomes via weighted longitudinal regression analyses such as negative binomial regression and generalized linear models depending on the outcome of interest.