Abbreviations and definitions for grouping participants based on lung function
| Abbreviation | Definition |
| PLD | Prematurity-associated lung disease |
| POLD-reversible | Prematurity-associated obstructive lung disease with evidence of bronchodilator reversibility (FEV1<LLN; FEV1/FVC ratio<LLN; bronchodilator response ≥10%) |
| POLD-fixed | Prematurity-associated obstructive lung disease with NO bronchodilator reversibility (FEV1<LLN; FEV1/FVC ratio<LLN; bronchodilator response <10%) |
| pPRISm | Prematurity-associated preserved ratio of impaired spirometry (FEV1<LLN; FEV1/FVC ratio≥LLN) |
| pDysanapsis | Prematurity-associated dysanapsis (FEV1≥LLN; FEV1/FVC<LLN) |
| Preterm controls | FEV1≥LLN; FEV1/FVC ratio≥LLN |
| Term controls | FEV1≥LLN; FEV1/FVC ratio≥LLN |
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LLN, lower limit of normal.