Registries such as the CFFPR are important tools for research, clinical care, and tracking incidence, mortality and population trends.

Background In 2011, the median age of survival in cystic fibrosis (CF) reported in the United States (US) was 36.8 years compared to 48.5 years in Canada; however direct comparison of survival estimates between national registries is challenging because of inherent differences in methodologies used, data processing techniques, and ascertainment bias. Objectives To use a standardized approach to calculate CF survival estimates and to explore differences between Canada and the United States (US). Design Population-based study. Setting 42 Canadian CF clinics and 110 CF care centers in the US. Patients Patients followed in the Canadian CF Registry (CCFR) and the US Cystic Fibrosis Foundation (CFF) Patient Registry (CFFPR) between 1990 and 2013. Measurement Cox proportional hazards models were used to compare survival between patients followed in the CCFR (n=5,941) and CFFPR (n=45,448). Multivariable models were used to adjust for factors known to be associated with survival. Results Median age of survival in patients with CF increased in both countries between 1990 and 2013; however in 1995 and 2005, survival in Canada increased at a faster rate relative to the US (p<0.001). Using contemporary data from 2009-2013, the median age of survival in Canada was ten years greater than the US (50.9 vs. 40.6 years, respectively). The adjusted risk of death was 34% lower in Canada compared to the US (hazard ratio 0.66, 95% CI 0.54-0.81). A greater proportion of patients had transplants in Canada (10.3% vs. 6.5% respectively, SD 13.7). Differences in survival between US and Canadian patients varied according to the US patients' insurance status. Limitations Ascertainment bias as a result of missing data or non-random lost to follow-up could impact the results. Conclusions Differences in CF survival between Canada and the US persisted after adjusting for risk factors associated with survival. Differential access to transplantation, improved post-transplant survival and differences in the healthcare systems may, in part, explain the Canadian survival advantage.

BACKGROUND AND OBJECTIVES: Cystic fibrosis transmembrane conductance regulator-related metabolic syndrome (CRMS) describes asymptomatic infants with a positive cystic fibrosis (CF) newborn screen (NBS) but inconclusive diagnostic testing for CF. Little is known about the epidemiology and outcomes of CRMS. The goal of this study was to determine the prevalence, clinical features, and short-term outcomes of infants with CRMS. METHODS:We analyzed data from the US CF Foundation Patient Registry (CFFPR) from 2010 to 2012. We compared demographic, diagnostic, anthropometric, health care utilization, microbiology, and treatment characteristics between infants with CF and infants with CRMS.

Background People with cystic fibrosis are managed differently in the US and UK providing an opportunity to learn from differences in practice patterns. Objectives To compare cross-sectional demographics, practice patterns and clinical outcomes between US and UK cystic fibrosis patients. Methods This was a cross-sectional study using 2010 data from patients in the US Cystic Fibrosis Foundation and the UK Cystic Fibrosis patient registries. The a priori outcome measures of interest were lung function and nutritional status. Descriptive statistics and two sample comparisons were performed. Stratification and multivariable linear regression was used to adjust for confounding. Results The study cohort included 13,777 children and 11,058 adults from the US and 3,968 children and 3,965 adults from the UK. In children, mean body mass index percentiles were similar. Lung function (FEV1 and FVC% predicted) was significantly higher in US patients ages 6 through 25 years of age. In a regression model adjusted for only age, FEV1% predicted was on average 3.31% of predicted (95% CI: 2.65, 3.96) higher in the US compared to the UK. When adjusted for age, age at diagnosis, gender, pancreatic insufficiency and genotype, FEV1% predicted was on average 3.03% of predicted (95% CI: 2.37, 3.69) higher in the US compared to the UK These differences persisted despite adjustment for possible confounders. Hypertonic saline and dornase alfa were much more commonly prescribed in US children. Conclusions Children and young adults with cystic fibrosis have better lung function in the US compared to the UK despite similar nutritional status.

The reasons for the observed improvements, and catch-up in the United States, are likely multifactorial and include the introduction of high-fat, high-calorie diets; introduction of newborn screening; and/or improved access to care for CF children in the United States.