According to ATS standards, a patient's FEV1 must increase by a minimum of what percent to demonstrate significant postbronchodilator improvement?

The correct answer is that a patient's FEV1 must increase by a minimum of 12 percent to demonstrate significant postbronchodilator improvement according to ATS (American Thoracic Society) standards. This percentage is based on clinical guidelines and research that aim to assess the effectiveness of bronchodilator therapy in patients with obstructive airway diseases, such as asthma and COPD (chronic obstructive pulmonary disease).

A 12 percent increase in FEV1 indicates a clinically relevant improvement in airflow, which can help guide treatment decisions and evaluate the response to bronchodilator medications. This standard also helps distinguish between meaningful changes in lung function as opposed to variations that may occur due to measurement error or other factors.

While other percentages, like 15 or 20, might be referenced in different contexts or studies, the ATS specifically identifies 12 percent as the threshold for significant clinical improvement in this scenario.