Objective:

To investigate population-level changes in asthma exacerbation trends before and after the onset of the respiratory biologics boom in 2015.

Approach:

• Study Design: Cohort study approved by the Mass General Brigham institutional review board, utilizing preexisting retrospective data.
• Patient Inclusion: Patients aged 18 years and older with physician-diagnosed asthma seen between January 1, 2006, and May 31, 2025, were included.
• Data Collection: Exacerbation events were defined and assigned to calendar years based on the index date, with annual exacerbation rates estimated.
• Statistical Analysis: Interrupted time series models and segmented multivariable linear regression were employed to estimate trends.
• Subgroup Analysis: Conducted by demographic and clinical characteristics, including age, sex, BMI, smoking status, and baseline eosinophil count.

Key Findings:

• Biologics have transformed treatment for severe asthma, reducing exacerbations and corticosteroid use.
• Limited data exist on the population-level impact of biologics on asthma exacerbations.
• The study aims to fill this gap by analyzing trends in exacerbations before and after the introduction of biologics.

Interpretation:

The study seeks to provide insights into the effectiveness of respiratory biologics at a population level, particularly in relation to asthma exacerbations.

Limitations:

• Exclusion of patients with other chronic lung diseases may limit generalizability.
• Potential misclassification in ICD coding could affect results.
• The study relies on retrospective data, which may have inherent biases.

Conclusion:

The study aims to clarify the impact of respiratory biologics on asthma exacerbation trends at the population level.