Intended for healthcare professionals

Letters Surgical mortality

Hospital episode statistics v central cardiac audit database

BMJ 2007; 335 doi: (Published 25 October 2007) Cite this as: BMJ 2007;335:839
  1. Paul Aylin, clinical reader in epidemiology and public health1,
  2. Alex Bottle, lecturer in medical statistics1,
  3. Paul Elliott, professor of epidemiology and public health2,
  4. Brian Jarman, emeritus professor3
  1. 1Dr Foster Unit at Imperial College, Department of Primary Care and Social Medicine, London SW7 2AZ
  2. 2Department of Epidemiology and Public Health, Faculty of Medicine, Imperial College, London W2 1PG
  3. 3Dr Foster Unit at Imperial College
  1. p.aylin{at}

    We published the follow-up of the Bristol Royal Infirmary analysis to which Westaby et al refer1 2 and have some comments on their paper.

    The online version suggests that the clinical teams did not verify the data. We wrote to the clinical team at Oxford over a year before our paper was published. After some months and a reminder letter sent to them, we received a response from the medical director of the trust which did not dispute our figures. His letter also confirmed that the trust had become aware of a downturn in their results before 2000. This was noted in our paper.

    We have previously made clear the limitations of using OPCS4 codes in defining open operations, in that there is no explicit code for open heart surgery. We used a definition arrived at by consultation for the Bristol inquiry.3 Because this definition differs from that used within the central cardiac audit database (CCAD), they are not directly comparable. The Thames Valley Strategic Health Authority's report (on which Westaby et al say their report is based) came to the same conclusion.4

    The mortality rates quoted in the Oxford paper differ importantly from the mortality figures quoted to us by the medical director of the trust. There are also differences in comparison with the official CCAD figures published on the congenital heart disease website (

    Paediatric cardiac surgery is a highly specialised, complex field. The Oxford paper's conclusions suggest that surgeons don't agree among themselves how best to monitor outcomes. We agree that the CCAD could potentially provide an alternative and improved data source for paediatric cardiac surgery outcomes. We also support the Thames Valley report's conclusions that hospital episode statistics and the CCAD both have an important role in measuring activity and outcomes in the clinical setting.4 Ideally, clinical and administrative datasets should function as one, but in any case, all clinicians should be prepared to take an active part in institutional data collection.5


    • Competing interests: PA, AB, and BJ are employed by Imperial College and work within the Dr Foster Unit at Imperial. The Dr Foster Unit at Imperial is funded by a research grant from Dr Foster Intelligence (an independent health service research organisation).


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