| Age years | Subjects | Acceptable manoeuvres per child | |||
| 0 | 1 | 2 | ≥3 | ||
| 4– <6 | 1052 | 457 (43) | 117 (11) | 120 (11) | 358 (34) |
| 6– <10 | 1510 | 322 (21) | 170 (11) | 201 (13) | 817 (54) |
| 10– <15 | 1599 | 254 (16) | 124 (8) | 143 (9) | 1078 (67) |
| 15– <19 | 1228 | 191 (16) | 103 (8) | 105 (9) | 829 (68) |
| Total¶ | 5415 | 1228 (23) | 519 (10) | 572 (11) | 3096 (57) |
Data are presented as n or n (%). #: n=5415 children with lung function testing from the LUNOKID study; ¶: includes children aged slightly <4 or >18 years.