Summary of data by centre before exclusions
| Participants n | Equipment | European ancestry | Obese | FEV1 z-score | |
| France | 184 | Jaeger MasterScreen | 97.8 | 10.9 | 0.24±0.92 |
| Italy | 3705 | SensorMedics Vmax | 100.0 | 24.0 | 0.31±0.96 |
| Australia | 128 | Eco Medics Exhalyzer | 93.0 | 8.6 | |
| Australia | 66 | SensorMedics Vmax | 100.0 | 4.6 | 0.26±0.91 |
| French Polynesia | 113 | CosMed | 22.1 | 39.8 | 0.67±1.00 |
| Australia | 123 | SensorMedics Spectra | 100.0 | 8.1 | 0.23±0.90 |
| Germany | 58 | ndd EasyOne Pro Lab | 100.0 | 8.6 | |
| Tunisia | 615 | Other | 100.0 | 22.8 | −0.31±1.16 |
| Australia | 91 | SensorMedics Spectra | 100.0 | 4.4 | |
| Mexico | 132 | Jaeger Master Screen | 100.0 | 7.6 | 0.20±0.97 |
| Spain | 545 | Jaeger Master Screen | 100.0 | 0.0 | −0.02±0.90 |
| Mexico | 164 | ndd EasyOne Pro Lab | 100.0 | 11.6 | 0.10±1.18 |
| Mexico | 453 | ndd EasyOne Pro Lab | 100.0 | 4.4 | |
| Switzerland | 82 | Eco Medics Exhalyzer | 100.0 | 2.4 | |
| Netherlands | 723 | Jaeger Master Screen | 100.0 | 4.0 | |
| United States | 59 | Medisoft BodyBox | 0.0 | 11.9 | 0.69±0.97 |
| United Kingdom | 160 | Jaeger Master Screen | 71.9 | 8.1 | −0.06±1.05 |
Data are presented as % or mean±sd, unless otherwise stated. Summary of data submitted to the Global Lung Function Initiative (GLI) lung volumes task force. Obesity was defined as body mass index (BMI) >95th centile in children and BMI >30 kg·m−2 in adults (aged >18 years). Some centres (n=11) submitted spirometry data from which the mean±sd of the forced expiratory volume in 1 s (FEV1) z-score was calculated using the GLI 2012 spirometry equations [1].