Carotid endarterectomy in Scotland: 1981-1996.

Background: Our aim was to assess the geographical, social and hospital variation in carotid endarterectomy (CEA) over time in Scotland using routinely generated data, and to assess the outcome of CEA in terms of the 7 day case-fatality.

Methods: A descriptive, retrospective study was carried out using computerized medical records at national level of all patients in Scotland who had a CEA during 1981-1996. Medical record linkage was used to identify the study population with the index event specified as CEA. The annual rate of CEA in Scotland and length of hospital stay for the procedure were determined. The geographical distribution of CEA, and the social circumstances of these CEA patients were described. Hospitals where CEAs were performed were evaluated in terms of high-, medium- and low-volume hospitals.

Results: A total of 2,892 CEA patients were identified for the period 1981-1996. The CEA rate increased from 1.2/100,000 (1989) to 8.6/100,000 (1996) with a maximum of 19/100,000 in Tayside Health Board (1994). Most of the CEAs in Scotland after the publication of the trials were in a small number of 'high'-volume hospitals (> 50 operations/year). There was no gender inequality in the provision of CEA in Scotland but substantial social and regional variation was observed. The 7 day operative mortality of 1.5 per cent was higher than that observed in the randomized trials.

Conclusions: CEA in Scotland is performed now at about the expected rate, but there are still probably too many operations being carried out in low-volume hospitals. Length of stay has decreased over time. The operative mortality, however, was higher than in the randomized trials.