Dutch CF Registry 2017 - Symptoms and consequences
Half of the children (under 18) had a pulmonary function over 94%. In adults, the pulmonary function is already much lower: half of patients had a pulmonary function over 70%.
It is important to measure the pulmonary function of people with CF. Due to the disturbed water-salt balance, the mucus in the lungs becomes thick and sticky. This causes bacteria to stick and cause infections and inflammations. As a result, the function of the lungs slowly but surely deteriorates. In the end, many people with CF die because the lungs are ‘exhausted’. The longer the pulmonary function remains good, the better the chances of survival.
A commonly used measure for the pulmonary function is FEV1% predicted: the volume of air a person can exhale in 1 second, compared to people without lung problems but with the same age, body height and sex.
Figure 1 below shows how the pulmonary function slowly deteriorates as the age of people with CF goes up. The median FEV1% predicted is shown for each age category. The median divides the group of people exactly in half: half have a lower pulmonary function, the other half a higher pulmonary function than the median value.
In order to make an international comparison of patients with CF, the pulmonary function is classified into categories: lower than 40%, 40-70%, 70-90%, and 90% and higher. Figure 2 below shows that for the past three years, most children in the Netherlands had a pulmonary function over 90%. In adults, most people had a pulmonary function of 40-70%.
Figures 3 and 4 below show the pulmonary function of children and adults per CF centre.