Aims To determine the stability of lung function test results of extremely preterm (EPT; < 28 weeks’ gestational age) or extremely low birthweight (ELBW; birthweight < 1000g) survivors between 8 and 18 years of age compared with term controls.
Methods Eighteen-year follow-up of participants born either EPT/ELBW in 1991–92 in the state of Victoria and randomly selected term, normal birthweight controls. Lung volumes and flows, including the forced expired volume in 1 second (FEV1), forced vital capacity (FVC), the FEV1/FVC, and the forced expiratory flow (FEF25–75%) were measured at 8 and 18 years of age according to standard guidelines and results converted to Z-scores for age, height and gender.
Results Lung function data were obtained from 187/298 (63%) EPT/ELBW subjects and 147/262 (56%) controls at both 8 and 18 years. There were strong positive relationships between lung function results at 18 years with results obtained at 8 years in both groups (Table).
Data are regression coefficients (SE); *P<0.001
Relationships between 8 and 18 years were significantly stronger for EPT/ELBW subjects for both FEV1 and FEF25–75% compared with controls.
Conclusions There are strong linear relationships between lung function values at 8 and 18 years in both EPT/ELBW survivors and controls.