Prospective Clinical Study on the Clinical Efficacy and Prognostic Outcome of ICS/LABA Combined With Liqin Zhike Formula in the Treatment of Cough Variant Asthma

Inclusion criteria

• ✓. Positive bronchodilator test: An increase in Forced Expiratory Volume in one second (FEV1) of ≥12% and an absolute increase in FEV1 of ≥200 ml after inhalation of a bronchodilator; OR an increase in FEV1 of ≥12% compared to baseline and an absolute increase of ≥200 ml after 4 weeks of anti-inflammatory treatment containing Inhaled Corticosteroids (ICS) (excluding respiratory infections).
• ✓. Positive bronchial provocation test: Commonly used inhaled agents are methacholine or histamine. A positive result is typically defined as a ≥20% decrease in FEV1 after inhalation of the provoking agent, indicating the presence of airway hyperresponsiveness. Bronchial provocation test can be performed when FEV1 is ≥70% of predicted value (excluding respiratory infections within 4 weeks). If FEV1 is \<70% of predicted value, a bronchodilator test is prioritized.
• ✓. Average daily diurnal variation in Peak Expiratory Flow (PEF) \>10% (calculated as the sum of daily PEF diurnal variation for at least 7 consecutive days divided by the total number of days), excluding respiratory infections.