Derya Karadeniz SİR, Adem YAĞAN, Tuncay ULU, Sevcan SAĞLAM
Van Medical Journal - 2026;33(4):437-444
Introduction: This study retrospectively evaluated the performance of the newborn cystic fibrosis (CF) screening program in Van Province between 2021 and 2025 by determining screening positivity and positive predictive value (PPV) and comparing findings with national and international data. Materials and Methods: This retrospective, descriptive, cross-sectional study analyzed aggregated records of newborns screened using the IRT/IRT algorithm within the National Newborn Screening Program. Annual and pooled screening positivity rates and PPVs were calculated. Exploratory temporal trends were assessed using binomial generalized linear models (GLMs), with quasi-binomial models used to account for overdispersion. Given the small number of annual observations (n=5), trend analyses were interpreted cautiously. Results: A total of 99,868 newborns were screened, of whom 370 (0.37%) were referred and 20 were confirmed to have CF, yielding a pooled positivity rate of 0.37% and PPV of 5.41%. Screening positivity decreased over time, whereas PPV increased, reaching its highest value (10.26%) in 2023. Conclusion: The PPV of the IRT/IRT-based newborn CF screening program in Van Province was substantially below the >=30% level recommended by the European Cystic Fibrosis Society, indicating a need to improve the diagnostic performance of the current screening algorithm. Multicenter prospective studies incorporating patient-level data and systematic monitoring of false-negative cases are warranted.
