Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the FEV1/FVC ratio indicative of COPD?

1. Greater than 1.0

2. Equal to 0.7

3. Less than 0.7

4. Approximately 0.8

The correct answer is: Less than 0.7

The FEV1/FVC ratio is a critical measurement in the evaluation of lung function and is particularly important in diagnosing chronic obstructive pulmonary disease (COPD). In individuals with COPD, the key characteristic is airflow obstruction, which is reflected in a reduced ratio of FEV1 (Forced Expiratory Volume in one second) to FVC (Forced Vital Capacity). A ratio of less than 0.7 indicates that FEV1 is significantly reduced compared to FVC, which is consistent with the pathophysiological changes in COPD where there is an obstruction to airflow. This measurement helps distinguish COPD from other lung conditions, such as restrictive lung diseases, which typically do not show the same degree of obstruction and would present with a normal or altered ratio in a different manner. The values "greater than 1.0," "equal to 0.7," and "approximately 0.8" do not represent the typical findings in COPD. A ratio greater than 1.0 suggests restrictive patterns or normal function, while a ratio of 0.7 or higher may not indicate significant obstruction, which is crucial for diagnosing COPD. Therefore, a ratio of less than 0.7 is an important indicator of obstructive diseases like COPD,