Here is a link to comments about the new GOLD COPD guidelines and here are the guidelines. Even with references it is only a merciful 26 pages.
The category of Stage 0 was eliminated which makes sense to those among us who wondered abut the logic of defining the first stage of a disease as a condition that poses the increased risk of that disease.
I was glad to see that mention was made of the problem of overestimating the degree of impairment using spirometry in elderly patients, particularly if one uses the percent predicted methods. This method designates a given FEV1 , for example, as 76 or some other number percent of predicted. This method works fairly well, although it never had sound statistical basis, it just happens to work reasonably well but older folks and shorter people tend to get short shrift and appear to be more imparted that they should be. Further there is a normal decrement in lung function which is incompletely "Corrected for" when one use the percent predicted formula.I don't have a solution for that other than be aware that the old folks' pulmonary function impairment may not be a severe as the percent predicted value would indicate.
Some of the old time lung doctor treatments are not recommended including mucolytic agents and continuous antibiotic prophylaxis.