What criteria do you use to classify a response as significant, borderline and no response?

Indices we are looking at are:

  1. FVC
  2. FEV1
  3. FEF25-75

Be careful with FEF25-75. If the FVC volume changes you cannot use the change in FEF25-75. The mid portion of FVC (FEF25-75) can shift to left (steep portion) or right (flat portion) if the FVC volume changes.