Regional distribution(% ex-actuator dose corrected for tissue attenuation) of extrafine aerosol (QVARTM; 3M Health Care Ltd, Loughborough, UK) in groups using the single maximal inhalation with breath-hold
| Age group yrs | Lungs % | Oropharynx+gastrointestinal % | Spacer % | Expiratory filter % |
| 5–7 | 58.1±6.7 | 12.9±3.2 | 24.1±7.0 | 4.9±4.7 |
| 8–10 | 56.6±5.2 | 20.1±9.5 | 18.2±1.6 | 5.1±4.6 |
| 11–17 | 58.4±9.2 | 20.8±8.8. | 20.3±4.5 | 0.6±0.6 |
Data are presented as mean±sd