Background Newborn screening (NBS) for cystic fibrosis (CF) is associated with improved early nutritional outcomes and improved spirometry in children. The aim of this study was to determine whether early diagnosis and treatment of CF with NBS in New South Wales in 1981 led to better clinical outcomes and survival into early adulthood.

Methods Retrospective observational study comprising two original cohorts born in the 3 years before (‘non-screened cohort’, n=57) and after (‘screened’; n=60) the introduction of NBS. Patient records were assessed at transfer from paediatric to adult care by age 19 years and survival was documented to age 25 years.

Results Non-screened patients (n=38) when compared with screened patients (n=41) had a higher rate and lower age of Pseudomonas aeruginosa acquisition at age 18 years (p≤0.01). Height, weight and body mass index (BMI) z scores (all p<0.01) and forced expiratory volume in 1 s (FEV₁)% were better in the screened group (n=41) (difference: 16.7±6.4%; p=0.01) compared to non-screened (n=38) subjects on transfer to adult care. Each 1% increase in FEV₁% was associated with a 3% (95% CI 1% to 5%; p=0.001) decrease in risk of death and each 1.0 kg/m² increase in BMI contributed to a 44% (95% CI 31% to 55%; p<0.001) decrease in risk of death. This accumulated in a significant survival difference at age 25 years (25 vs 13 deaths or lung transplants; p=0.01).

Conclusion NBS for CF leads to better lung function, nutritional status and improved survival in screened patients in early adulthood.