The challenge of benchmarking: surgical volume and operative mortality in Veterans Administration Medical Centers.

Background: This study examines the relationship between hospital surgical volume and operative modality rate. Emphasis is placed on the role of referral patterns; the effects of variation in patient condition, operative procedures, and hospital characteristics, and the contribution of volume of related procedures, in addition to specific-procedure volume, the definition of operative mortality, and their influence on surgical outcome.

Methods: This cohort study included all Department of Veterans Affairs Medical Centers with surgery programs. All patients in five operation-diagnosis sets (colectomy for cancer, colectomy without cancer, amputation above the knee, coronary artery bypass grafting for old myocardial infarction, and open-heart valvuloplasty), discharged from 1987 through 1989, were assessed to determine the risk-adjusted 30-day postoperative morality rate.

Results: Only one of the studied groups, valvuloplasty, demonstrated a significant inverse relationship between hospital surgical volume and operative mortality rate. No additional effect on outcome owing to related procedure volume was noted.

Conclusions: This study demonstrates some of the difficulties in assessing surgical results and that we should be skeptical of the intuitively attractive notion that high annual volumes of operations will necessarily result in improved outcomes. This is congruent with recent literature in which there is no broad-based evidence that hospital surgical volume affects operative mortality rate.