Comparative audit between hospitals: the example of appendectomy.

How useful are routine, comparative audit systems? To attempt to answer this question, data from a system in North West Thames were used. A common procedure was selected (appendectomy) and data supplied by 17 surgeons between January and June 1990 were analysed. Aspects of the case-mix, clinical management, diagnostic accuracy and patient outcomes for the surgeons were compared. A total of 401 patients had been treated. All aspects of care varied between surgeons: mean age of patients (19-36 years), proportion of female patients (30-75 per cent), mean length of stay (2.1-7.1 days), prophylactic antibiotic use (0-85 per cent), diagnostic accuracy (40-100 per cent) and incidence of wound infections (0-4 per cent). As a result of the small sample sizes (mean number of cases per surgeon was 23.6) few of these differences were statistically significant. In addition, there were some doubts about the accuracy of some of the data. If such methodological difficulties can be overcome, comparative audit systems offer a practical and useful way of uncovering unusual clinical practices and generating hypotheses for evaluative research.