Hospital volume and surgical outcomes for elderly patients with colorectal cancer in the United States.

BACKGROUND: Recent emphasis has been placed on the quality of surgical care in the United States. As such, patients, providers, and payers are increasingly aware of the outcomes of surgical care as a marker of quality. The objective of this study was to determine the impact of hospital volume on mortality for patients of different age groups to determine whether elderly patients would derive more benefit from selective referral policies.

METHODS: Data from the Nationwide Inpatient Sample for all patients undergoing surgery for colorectal cancer during 1997 were obtained (N = 20,862). Differences in mortality associated with increasing age and hospital volume quartiles were determined. Risk-adjusted analyses of mortality were performed using multiple logistic regression.

RESULTS: The overall mortality rate was 3.1% for the 842 hospitals included. Patient age breakdown was the following: age <50, 7%; age 50 to 64, 19%; age 65 to 80, 51%; and age >80, 22%. Increasing age was associated with higher mortality rates: age <50, 0.8%; age 51 to 65, 1.3%; age 66 to 80, 2.9%; and >80, 6.9%. Overall, the highest volume hospitals (HVH) (>150/year) had lower mortality than the lowest volume hospitals (LVH) (<55/year) (2.5% vs. 3.7%; P = 0.006). However, the effect of volume on mortality was primarily due to differences in older patients. For patients greater than 65 years old, the mortality rate was 3.1% at HVH and 4.5% at LVH (P = 0.03). For patients greater than 80 years old, the mortality rate was 4.6% at HVH and 7.3% at LVH (P = 0.04). The results were unchanged after adjustment for patient demographics, comorbid disease, site of cancer, and type of resection.

CONCLUSIONS: The majority of deaths after surgery for colorectal cancer occur in older patients. Hospitals that perform higher volumes of colorectal resection have lower mortality rates, especially for older patients. In the absence of other information about the quality of surgical care, provider volumes are a useful marker of postoperative outcomes for older patients in need of surgery for colorectal cancer.