The Global Lungs Initiative (GLI) equations are the first global multi-ethnic reference equations for spirometry that span all-ages. These are the result of unprecedented, unselfish and professional international cooperation endorsed by five international societies. Briefly, data from 74,187 healthy non-smokers (57.1% females) aged 3-95 years were used to derive multi-ethnic reference equations using modern statistical methods, including development of age dependent lower limits of normal.
A macro has been created for use in the statistical program SAS. You can find the zip file with everything you need here. Ensure you keep all the files in the zip folder together and follow the help file included. (Version2 4/7/13)
Note the SAS macro was recently updated to be consistent with the updated look-up tables (April 2013).