AAA benchmarking by Dr Foster: a cause for concern?

INTRODUCTION: The publication of interpretable performance data for hospitals is an important service. In November 2002, the medical benchmarking company Dr Foster published a league table based on the results of abdominal aortic aneurysm (AAA) repair. The purpose of our study was to establish the validity of the data used in benchmarking. PATIENTS AND METHODS: Data on elective infra-renal AAA (IRAAA) repair was obtained from three sources. Data used by Dr Foster was based on the hospital PAS system. The databases for both Dr Foster and PAS were analysed and cross-referenced to the vascular unit database maintained by a separately employed audit co-ordinator. RESULTS: Of 395 total aortic aneurysm repairs, 223 (56%) were identified as elective IRAAA repairs on the unit database. Of these, 125 were identified on the PAS database and 115 on the Dr Foster database. The number of deaths was the same in both the unit and Dr Foster databases (n = 11) but the Dr Foster database included deaths in patients who had undergone juxtarenal (n = 1), Type III TAAA (n = 2) and Type IV TAAA (n = 4) repairs and omitted 7 deaths following IRAAA. The sensitivity and specificity for the PAS dataset was 0.51 and 0.93, respectively. For Dr Foster, the results were worse with a sensitivity and specificity of 0.41 and 0.86, respectively. The accuracy of the data was 0.6 and 0.69 for Dr Foster and PAS, respectively. Standardised mortality ratios (SMRs) were used to rank hospitals. Dr Foster's published SMR for elective AAA repair for our unit was 160. The actual SMR was 67. CONCLUSIONS: Robust and accurate published league tables should be supported and commended but currently available data appear to be misleading and may cause unnecessary concern to patients.

Renal dysfunction and prolonged visceral ischaemia increase mortality rate after suprarenal aneurysm repair.

BACKGROUND: Elective juxtarenal abdominal aneurysm repair has a significantly lower mortality rate than suprarenal repair. Identification of factors affecting outcome may lead to a reduction in mortality rate for suprarenal repair. METHODS: Data were collected prospectively between 1993 and 2000 for 130 patients who underwent type IV thoracoabdominal aneurysm (TAA) repair and 44 patients who had juxtarenal aneurysm (JRA) repair. Preoperative risk factors and operative details were compared between groups and related to outcome after TAA repair (there were only two deaths in the JRA group). RESULTS: The in-hospital mortality rate was significantly higher following TAA repair (20.0 per cent; 26 of 130 patients) than JRA repair (4.5 per cent; two of 44). Raised serum creatinine concentration was the only preoperative factor (P = 0.013) and visceral ischaemia the only significant operative factor (P = 0.001) that affected mortality after TAA repair. CONCLUSION: JRA repair was performed with similar risks to those of infrarenal aneurysm repair. Impaired preoperative renal function was related to death following TAA repair and conservative treatment should be considered for patients with a serum creatinine level above 180 micromol/l. Reducing the duration of visceral ischaemia might improve outcome.