Risk-adjusted analysis of surgeon performance: a 1-year study.

A 1-year prospective analysis was undertaken of all non-day-case general surgery in a district general hospital. Using the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) scoring system 3004 patients were assessed. From the predictions of mortality and morbidity so obtained, a quality measure, the ratio of observed to expected numbers of deaths and complications (O:E ratio) was determined for each surgeon, both overall and within specialty zones. The present study demonstrates the serious hazard in using 'raw' uncorrected mortality and morbidity statistics to compare surgeon performance. Mortality rates varied from 1.0 to 4.9 per cent whereas O:E ratios ranged from 0.83 to 1.06; morbidity rates varied from 5.3 to 12.6 per cent with O:E ratios 0.86-1.02. Great misunderstanding may result from the publication of surgeon or hospital 'league tables'. The present study demonstrates a technique that might allow surgeon performance to be monitored adequately and accurately.