Age distribution
Due
to the study design relatively few young men and women were
recruited for the Vlaardingen-Vlagtwedde study.
Most participants were in the 30 - 50 year age range. The
number of participants diminishes quickly between 50 and 80
year of age. This is mostly to do with ‘survival of
the fittest’. As the population ages, i.e.
more people survive to an old age, the influence of ‘positive
selection’ is likely to become more pronounced. As the
number of elderly people is limited, predictions of ventilatory
function in this age group will always be less accurate than
in younger adults.