Values for the lower limits of normal
| Sex | Male | Male | Female | |||
| Age (years) | 30 | 70 | 70 | |||
| Height (m) | 1.80 | 1.80 | 1.55 | |||
| LLN as % pred | 80% pred as centile | LLN as % pred | 80% pred as centile | LLN as % pred | 80% pred as centile | |
| FEV1 | 81 | 4 | 74 | 10 | 65 | 18 |
| FVC | 81 | 4 | 76 | 8 | 67 | 24 |
| FEV1/FVC | 86 | 1 | 84 | 2 | 86 | 2 |
| PEF | 80 | 5 | 76 | 9 | 72 | 19 |
| FRC | 71 | 13 | 74 | 11 | 68 | 20 |
| RV | 62 | 19 | 75 | 10 | 70 | 17 |
| TLC | 84 | 2 | 84 | 2 | 78 | 10 |
| RV/TLC | 65 | 17 | 78 | 7 | 78 | 6 |
| TLco | 81 | 4 | 75 | 9 | 70 | 18 |
| Kco | 75 | 9 | 66 | 17 | 79 | 12 |
Showing the LLN when expressed as per cent of predicted (pred) and 80% of predicted when expressed as population centile for a range of lung function indices for three different subjects.
Source: Professor MR Miller.
FEV1, forced expiratory volume in 1 s; FRC, functional residual capacity; FVC, forced vital capacity; Kco, gas transfer coefficient for carbon monoxide; LLN, lower limit of normal; PEF, peak expiratory flow; RV, residual volume; TLC, total lung capacity; TLco, carbon monoxide transfer factor.