Elizabeth A. Cromwell

Introduction: The Canadian Cystic Fibrosis Registry (CCFR) was developed in the 1970s and has longitudinal demographic and clinical data on persons living with cystic fibrosis (CF) attending accredited clinics in Canada. We aimed to validate the data collection and identify potential limitations of the CCFR. Methods: Of 40 accredited CF clinics in Canada invited and based on an a priori sample size calculation, eight clinics were included. 15% of each CF clinic’s population in 2019 were randomly selected. Data variables were selected based on their importance to care, epidemiologic trends, and data related to demography, clinic visits, and hospitalizations. The accuracy of the registry data was compared to the medical records as the gold standard. Each data element was categorized as correct, incorrect, or not able to be validated. The accuracy rate was calculated as the percent correct out of all records validated. Results: A total of 4382 individuals had data entered into the CCFR in 2019. The validation cohort consisted of 208 individuals from 8 clinics, which were representative across location, size of clinic (small/medium/large), and type of clinic (adult, pediatric, and combined). The 208 individuals were 52% male and 95% White, and with a median age of 26.3 years (IQR: 15.2–36.6). Approximately 95% of CCFR data on clinical measurements, infections, treatments, and hospitalizations validated were accurate as compared to the medical record. For demography, sex and date of birth had 100% accuracy. Conclusion: Our validation of the CCFR demonstrated high accuracy for clinical and demographic variables used in clinical research.

Background: The benefit of antibiotic treatment of acute drops in FEV ₁ percent predicted (FEV ₁ pp) has been clearly established, but data from the early 2000s showed inconsistent treatment. Further, there is no empirical evidence for what magnitude of drop is clinically significant. Methods: We used data from the CF Foundation Patient Registry (CFFPR) from 2016 to 2019 to determine the association between treatment (any IV antibiotics, only oral or newly prescribed inhaled antibiotics, or no antibiotic therapy) following a decline of ≥5% from baseline FEV ₁ pp and return to 100% baseline FEV ₁ pp days using multivariable logistic regression including an interaction between the magnitude of decline and treatment category. Results: Overall, 16,495 PWCF had a decline: 16.5% were treated with IV antibiotics, 25.0% non‐IV antibiotics, and 58.5% received no antibiotics. Antibiotic treatment was more likely for those with lower lung function, history of a positive PA culture, older age and larger FEV ₁ decline ( p < 0.001). Treatment with IV antibiotics or oral/inhaled antibiotics was associated with a higher odds of recovery to baseline compared to no treatment across all levels of decline, including declines of 5%–10%. Conclusions: A large proportion of acute drops in FEV1 _pp continue to be untreated, especially in younger patients and those with higher baseline lung function. Acute drops as small as 5% predicted are less likely to be recovered if antibiotic treatment is not prescribed. These findings suggest the need for more aggressive antimicrobial treatment of acute drops in FEV ₁ , including those of a magnitude previously believed to be associated with self‐recovery.