FEV1: GLI-2012 Equation-Derived Percentiles
No published paper provides pre-tabulated FEV1 percentile tables covering the full 3 to 95 year age range at the bracket granularity used here. The Global Lung Function Initiative 2012 (GLI-2012) equations (Quanjer et al., DOI: 10.1183/09031936.00080312) provide sex-specific regression equations that predict FEV1 as a function of age, height, and ethnicity using the LMS method. Percentiles are derived as follows:
- Equations: the coefficient set GLI labels "Caucasian" is used (all ethnicity flags set to zero), representing 81% of male and 86% of female subjects in the GLI dataset. Lspline, Mspline, and Sspline values are read from the GLI supplementary lookup table (
lookuptables.xls) and linearly interpolated at each bracket midpoint age. - Height assumption: FEV1 is height-dependent. Each age-sex bracket uses the NHANES median standing height for that group (Fryar et al. 2021, DOI: 10.15620/cdc:103734). Heights used (cm): see table below.
- Percentile formula:
P = M × (1 + L × S × z)1/L, where z is the standard normal quantile. All five percentiles (P5, P25, P50, P75, P95) are computed natively, with no approximation or substitution.
| Bracket | Males (cm) | Females (cm) |
|---|---|---|
| 5-9 | 119.5 | 118.5 |
| 10-14 | 149.0 | 151.5 |
| 15-19 | 175.5 | 162.5 |
| 20-29 | 176.4 | 162.1 |
| 30-39 | 176.0 | 162.0 |
| 40-49 | 175.7 | 161.8 |
| 50-59 | 174.5 | 161.0 |
| 60-69 | 172.5 | 159.5 |
| 70-79 | 170.0 | 157.5 |
| 80+ | 168.0 | 155.0 |
These pages reproduce a specific GLI-2012 equation and therefore inherit its population model and limitations, including its use of ethnicity-specific coefficients. In a 2023 official statement, the American Thoracic Society recommended against race- and ethnicity-specific reference equations for spirometry interpretation, favouring race-neutral reference values (Bhakta et al. 2023; endorsed by the European Respiratory Society). The percentiles here document a reproduction of the 2012 model, not current clinical guidance; an individual spirometry result should be interpreted from the full report with a qualified clinician.
Full source details and limitations are on the GLI-2012 reference page.