The computer graded the QFVC=A and the QFEV1=F. The lower computer FEV1 grade is because the FEV1 is not repeatable. The second highest FEV1 is 372 ml lower than the highest FEV1 -- much greater than the 150 ml repeatability criteria. The lack of a repeatable FEV1 is due to both an incomplete inhalation, as shown by variations in the FVC, and due to variations in initial effort as shown by lower peak flows. Only one curve (#1, black) has both a good start of test (larger peak flow) and a good inhalation (within 89 ml of the largest FVC). Although the FEV1 is not repeatable, the shape of curve #1 and its corresponding FVC indicate that its FEV1 likely represents a maximal effort FEV1 and thus the revised grades of QFVC=B and QFEV1=C. A slightly lower FVC grade is used to indicate the variability in the volume-time curve at the end of the test.
