Comparing cystic fibrosis outcomes across the pond

Comparative analysis of coverage data in CF registries has demonstrated how this can influence outcomes when registries are differentially representative of their respective total estimated population. 3 In the UK, the registry is estimated to capture almost all of the CF population, and any patients attending the National Health Service clinics will have data routinely collected into the database. 4 By contrast, the US registry collects data on patients seen in US accredited CF centres and may have lower coverage. 5 Older estimates suggest that coverage in the US registry was about 75% in the 1990s, 3 during a period when the UK CF survey, a precursor of the UK registry, had almost complete coverage of the UK population. 6 It is possible that the US registry does not capture individuals across the full range of the socio-economic spectrum to the same extent as the UK registry due to the nature of the healthcare system in the USA, where the uninsured and those with poorer access to care may be under-represented. [...]a consequence of the high level of population coverage in the UK, coupled with a universal healthcare system, is that the UK registry may more accurately represent more disadvantaged groups, which we know from studies in the UK and the USA have worse clinical outcomes. 4 7 Let us assume that the US dataset does not represent the most disadvantaged to the same extent: could this create the differences observed?