2
Key Points
➤ Interpretation of pulmonary function tests (PFTs) must take into
account a level of uncertainty relating to:
i. how representative the obtained result was of the individual's lung function at the
time of testing,
ii. how the pre-test probability of disease may influence what is the appropriate
threshold for that individual, and
iii. how valid for the individual the reference population is against which the test is
being judged.
➤ In the future it may also be reasonable to set clinical decision-making
thresholds for a test based on clinical risk and observed clinical
outcomes.
➤ A more comprehensive approach to interpretation (not simply
relying on whether results are within or outside the normal range)
is imperative for appropriate interpretation of lung function when
pre-screening for employment, for tracking the effects of exposure,
for disability assessment, and for risk assessment for therapies
potentially toxic to the lungs.
➤ The interpretation of PFT results must always consider the inherent
biological variability of the tests and the uncertainty of the test result.
