Impact of Using Pre- and Postbronchodilator Spirometry Reference Values in a Chinese Population

Area of Science:

• Pulmonary Medicine
• Respiratory Physiology
• Epidemiology

Background:

• Spirometry is essential for diagnosing and managing respiratory diseases.
• Nationally representative spirometry reference equations are needed for the Chinese population.
• The impact of pre-bronchodilator (pre-BD) versus post-bronchodilator (post-BD) reference values in Chinese adults remains unassessed.

Purpose of the Study:

• To establish pre-BD and post-BD spirometry reference values for Chinese adults.
• To evaluate the differences in disease prevalence and severity grading using pre-BD versus post-BD references.
• To assess the clinical utility of post-BD reference values in identifying obstructive lung diseases.

Main Methods:

• Utilized data from the China Pulmonary Health (CPH) Study, including 17,969 healthy non-smokers for reference value calculation.
• Calculated pre-BD and post-BD reference values for FEV1, FVC, and FEV1/FVC ratio.
• Applied these reference values to the entire CPH cohort (N=50,991) to compare disease prevalence and severity.

Main Results:

• Airflow limitation prevalence was 5.36% using pre-BD and 8.02% using post-BD references.
• Individuals with a post-BD FEV1/FVC below the post-BD reference but above the pre-BD reference reported more respiratory symptoms and had poorer spirometry.
• An additional 3.51% of participants were identified with grade II-IV COPD when using post-BD FEV1 predicted values.

Conclusions:

• Generated and applied pre- and post-BD spirometry reference values for a representative Chinese adult population.
• Post-BD reference values enhance the identification of individuals at risk for obstructive pulmonary diseases.
• Further investigation into the diagnostic and prognostic value of post-BD reference values is warranted.