Influence of hospital procedure volume on outcomes following surgery for colon cancer.
BACKGROUND
Survival following high-risk cancer surgery, such as pancreatectomy and esophagectomy, is superior at hospitals where high volumes of these procedures are performed. Conflicting evidence exists as to whether the association between hospital experience and favorable health outcomes also applies to more frequently performed operations, such as those for colon cancer.


OBJECTIVE
To determine whether hospital procedure volume predicts survival following colon cancer surgery.


METHODS
Retrospective cohort study of data from the Surveillance, Epidemiology and End Results-Medicare linked database on 27 986 colon cancer patients aged 65 years and older who had surgical resection for primary adenocarcinoma diagnosed between 1991 and 1996.


METHODS
Thirty-day postoperative mortality and overall and cancer-specific long-term survival, by hospital procedure volume.


RESULTS
We found small differences in 30-day postoperative mortality for patients treated at low- vs high-volume hospitals (3. 5% at hospitals in the top-volume quartile vs 5.5% at hospitals in the bottom-volume quartile). However, the correlation was statistically significant and persisted after adjusting for age at diagnosis, sex, race, cancer stage, comorbid illness, socioeconomic status, and acuity of hospitalization (P<.001). The association was evident for subgroups with stage I, II, and III disease. Hospital volume directly correlated with survival beyond 30 days and also was not attributable to differences in case mix (P<.001). The association between hospital volume and long-term survival was concentrated among patients with stage II and III disease (P<.001 for both). Among stage III patients, variation in use of adjuvant chemotherapy did not explain this finding.


CONCLUSIONS
Our data suggest that hospital procedure volume predicts clinical outcomes following surgery for colon cancer, although the absolute magnitudes of these differences are modest in comparison with the variation observed for higher-risk cancer surgeries.
Schrag
D
D
Department of Epidemiology and Biostatistics, Health Outcomes Research Group, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10021, USA. schragd@mskcc.org
Cramer
L D
LD
Bach
P B
PB
Cohen
A M
AM
Warren
J L
JL
Begg
C B
CB
D000230:Adenocarcinoma / Q000401:mortality / Q000601:surgery; D000368:Aged; D003110:Colonic Neoplasms / Q000401:mortality* / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000401:mortality* / Q000706:statistics & numerical data*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D006278:Medicare; D010043:Outcome and Process Assessment, Health Care; D012044:Regression Analysis; D012189:Retrospective Studies; D018426:SEER Program; D013503:Surgery Department, Hospital / Q000592:standards* / Q000706:statistics & numerical data*; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology