When using the Quanjer GLI-2012 spirometry equations, how do I deal with predicted values for lung volumes and transfer factor?

Manufacturers and their clientele may be wondering how to deal with predicted values for lung volumes (RV, TLC, FRC) and for transfer factor (‘diffusion capacity’). As long as no updated reference values for these indices are available, the obvious avenue is to continue using prediction equations that were hitherto used. The new GLI TL,CO equations can be used for transfer factor, and GLI lung volume equations are currently being derived.