Hospital volume and operative mortality in cancer surgery: a national study.

BACKGROUND

Although initiatives to regionalize cancer surgery are already under way, the relative importance of volume in cancer surgery is disputed.

HYPOTHESIS

We examined surgical mortality with 8 cancer resections in the US population to better quantify the influence of hospital volume.

METHODS

Using information from the all-payer Nationwide Inpatient Sample (1995-1997), we examined mortality with 8 cancer resections (N = 195 152). After dividing patients into 3 evenly sized volume groups based on hospital procedure volume (low, medium, and high), we used regression techniques to describe relationships between hospital volume and in-hospital mortality, adjusting for patient characteristics.

RESULTS

Trends toward lower operative risks at high-volume hospitals were observed for 7 of the 8 procedures. However, differences between low- and high high-volume hospitals were statistically significant for only 3 operations (esophagectomy, 15.0% vs 6.5%; pancreatic resection, 13.1% vs 2.5%; and pulmonary lobectomy, 10.1% vs 8.9%, respectively). Although they did not reach statistical significance, absolute differences in mortality between low- and high-volume hospitals were greater than 1% for the following 3 procedures: gastrectomy, 8.7% vs 6.9%; cystectomy, 3.6% vs 2.5%; and pneumonectomy, 10.6% vs 8.9%, respectively. Mortality reductions for nephrectomy and colectomy were small. In general, in terms of absolute differences in mortality, the effect of volume was greatest in elderly patients.

CONCLUSIONS

Operative mortality decreases with increasing hospital volume for several cancer resections. However, volume may be most important in patients who are older and at higher risk.