Certified Pulmonary Function Technologist (CPFT) Practice Exam

When conducting a spirometry test, how should data be analyzed to ensure accurate results?

1. Using only the FEV1 value

2. Comparing to the predicted values for age, gender, and height

3. Utilizing multiple testing sessions

4. Ignoring outlier results

The correct answer is: Comparing to the predicted values for age, gender, and height

The analysis of spirometry data requires comparing the obtained results to predicted values that take into account the individual's age, gender, and height. This comparison is crucial because it allows for an accurate assessment of lung function relative to what is expected for a person of similar demographics. Such predicted values indicate the normal ranges of various parameters, such as FEV1 (Forced Expiratory Volume in one second), FVC (Forced Vital Capacity), and the FEV1/FVC ratio, enabling healthcare professionals to identify possible obstructive or restrictive lung diseases. Using only the FEV1 value would not provide a comprehensive understanding of lung function, as it does not consider other important parameters like FVC or peak expiratory flow. Similarly, multiple testing sessions can be helpful in certain contexts, such as to check the reproducibility of results or if there’s variability; however, this is secondary to the initial comparison to predicted values. Ignoring outlier results can lead to misinterpretation and misdiagnosis; therefore, outliers should be contextualized rather than disregarded. Thus, comparing the observed results to the predicted values, with adjustments for individual characteristics, is fundamental in analyzing spirometry data accurately.