Does current reporting of lung function by the UK cystic fibrosis registry allow a fair comparison of adult centres?

BACKGROUND: Outcome data for UK cystic fibrosis centres are publicly available in an annual report, which ranks centres by median FEV1 % predicted. We wished to assess whether there are differences in lung function outcomes between adult centres that might imply differing standards of care.

METHODS: UK Registry data from 4761 subjects at 34 anonymised adult centres were used to calculate mean FEV1 % and rate of change of lung function for 2007-13. These measures were used to rank centres and compare outcomes.

RESULTS: There are minor differences between centres for mean FEV1 % for some years of the study and for rate of change of lung function over the study period. However, rankings are critically dependent on the outcome measure chosen and centre variation becomes negligible once patient population characteristics are taken into account.

CONCLUSIONS: We have demonstrated that the ranking of centres is biased and any apparent difference in respiratory outcomes is unlikely to be related to differing standards of care between centres.