Abstract
OBJECTIVE: This study aimed to evaluate 5-year outcomes of a structured quality improvement (QI) program implemented as part of the standard of care at our CF center, focusing on changes in body mass index (BMI) and forced expiratory volume in 1 s (FEV₁) in pwCF followed at our institution. METHODS: The medical records of pwCF registered at our CF center between January 1, 2018, and December 31, 2022, were retrospectively reviewed. Demographic and clinical data of pwCF submitted by our center to the European Cystic Fibrosis Society Patient Registry (ECFSPR) were used for this analysis. Structured QI strategies were initiated in 2018 after collaboration with the University of Michigan CF Center and focused on nutrition, respiratory care, and treatment adherence. Time-dependent changes in FEV1 percent predicted (FEV1pp) were evaluated using a linear mixed-effects regression model. RESULTS: All 440 pwCF followed at our center during the study period were included in the analysis. Over 5 years, BMI z-scores improved significantly in children (p < 0.001), while adult BMI remained stable (p = 0.10). No significant linear change in mean FEV₁pp was observed in adjusted longitudinal models (p > 0.05), however, descriptive analyses showed an increase in median FEV₁pp among adults. Higher BMI was associated with better lung function (p < 0.001) and lower IV antibiotic burden in correlation analyses (children: p < 0.001; adults: p = 0.045). The estimated mean survival age of the analysis cohort was 46.1 years. CONCLUSION: To our knowledge, this is the first report of a cohort of Turkish pwCF summarizing 5-year longitudinal registry data with survival estimates. These findings suggest that sustained, center-wide QI efforts may help maintain or improve clinical outcomes, particularly in settings with limited access to CFTR modulators.