Spirometry reference equations for central European populations from school age to old age.

Spirometry reference values are important for the interpretation of
spirometry results. Reference values should be updated regularly,
derived from a population as similar to the population for which
they are to be used and span across all ages. Such spirometry
reference equations are currently lacking for central European
populations. To develop spirometry reference equations for central
European populations between 8 and 90 years of age. We used data
collected between January 1993 and December 2010 from a central
European population. The data was modelled using "Generalized
Additive Models for Location, Scale and Shape" (GAMLSS). The
spirometry reference equations were derived from 118'891
individuals consisting of 60'624 (51%) females and 58'267 (49%)
males. Altogether, there were 18'211 (15.3%) children under the age
of 18 years. We developed spirometry reference equations for a
central European population between 8 and 90 years of age that can
be implemented in a wide range of clinical settings.