ABSTRACT
COPD, various attempts have been made to
produce categories of severity. These are based
on the degree of loss of FEV1 compared with
predicted values.1 Although they generally
relate to the severity of symptoms and the
intensity of treatment, there is no strict
rationale for the levels chosen, and some of
the major international guidelines published
over the last few years have chosen different
levels. These have been used to guide the
advice on categories of treatment within the
guidelines.
