Comparison of UK paediatric cardiac surgical performance by analysis of routinely collected data 1984-96: was Bristol an outlier?
BACKGROUND
Reports of high mortality after paediatric cardiac surgery at the Bristol Royal Infirmary, UK, led to the establishment of an independent public inquiry. A key question was whether or not the mortality statistics in Bristol were unusual compared with other specialist centres. To answer this question, we did a retrospective analysis of mortality in the UK using two datasets.


METHODS
Data from the UK Cardiac Surgical Register (CSR; January, 1984, to March, 1996) and Hospital Episode Statistics (HES; April, 1991, to December, 1995) were obtained for all 12 major centres in which paediatric cardiac surgery is done in the UK. The main outcome measure was mortality within 30 days of a cardiac surgical procedure. We estimated excess deaths in Bristol using a random-effects model derived from the remaining 11 centres. Additionally, a sensitivity analysis was done and case-mix examined.


RESULTS
For children younger than 1 year, in open operations, the mortality rate in Bristol was around double that of the other centres during 1991-95: within the CSR, there were 19.0 excess deaths (95% interval 2-32) among 43 deaths; and in HES, there were 24.1 excess deaths (12-34) among 41 deaths recorded. There was no strong evidence for excess mortality in Bristol for closed operations or for open operations in children older than 1 year.


CONCLUSIONS
Our results suggest that Bristol was an outlier, and we do not believe that statistical variation, systematic bias in data collection, case-mix, or data quality can explain a divergence in performance of this size.
Aylin
P
P
Division of Primary Care and Population Health Sciences, Imperial College School of Medicine, London, UK. p.aylin@ic.ac.uk
Alves
B
B
Best
N
N
Cook
A
A
Elliott
P
P
Evans
S J
SJ
Lawrence
A E
AE
Murray
G D
GD
Pollock
J
J
Spiegelhalter
D
D
D000293:Adolescent; D000367:Age Factors; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D016208:Databases, Factual; D004739:England; D006801:Humans; D007223:Infant; D012042:Registries / Q000706:statistics & numerical data; D012189:Retrospective Studies; D015996:Survival Rate