DS will be turning 7 in a few weeks. He has pulmonary function tests every 6 months and has since he was 5. His pulmonologist says that these are "practice" tests as she doesn't feel that they are 100% but give enough information to have value. DS loves taking the pulmonary function tests as he gets to blow in a tube and on a computer screen can make toast pop up or a balloon pops. It makes a HUGE difference with who does the test. DS pulmonologist is very familiar with DS and makes sure that only certain people perform his test.