Comparison of the US and Australian Cystic Fibrosis Registries: The Impact of Newborn Screening

Abstract

BACKGROUND AND OBJECTIVES: National data registries for cystic fibrosis (CF) enable comparison of health statistics between countries. We examined the US and Australian CF data registries to compare demographics, clinical practice and outcome measures. METHODS: We compared the 2003 US and Australian registries. Differences in pulmonary and growth outcomes were assessed by creating models controlling for differences in age, gender, genotype, and diagnosis after newborn screening. RESULTS: Data on 12 994 US and 1220 Australian patients aged ≤18 years were analyzed. A significant difference was noted in the proportion who had been diagnosed after newborn screening (Australian 65.8% vs United States 7.2%; P < .001). Australian children had significantly greater mean height percentile (41.0 vs 32.6; P < .001) and weight percentile (43.5 vs 36.1; P = .028) than US children. Mean forced expiratory volume in 1 second (FEV1) percent predicted adjusted for age, gender, and genotype was similar in the 2 countries (P = .80). Patients diagnosed after newborn screening had higher mean FEV1 (5.3 [95% confidence interval (CI): 3.6–7.0]) percent predicted and BMI (0.26 [95% CI: 0.09–0.43]). Mean FEV1 of Australian patients diagnosed after newborn screening was lower by 5.2 (95% CI: 2.8–7.6) percent predicted compared with US children. CONCLUSIONS: Children diagnosed with CF after newborn screening benefited from better lung function and BMI than those diagnosed clinically. The benefit of newborn screening on lung function was significantly less in Australian children compared with US children. Statistical comparisons between CF registries are feasible and can contribute to benchmarking and improvements in care.