Volume-outcome relationships for head and neck cancer surgery in a universal health care system.
OBJECTIVE
We aimed to assess whether surgeon and/or institution resection volume predicts long-term overall survival in head and neck cancer in a publicly funded healthcare system.


METHODS
Population-based retrospective cohort study.


METHODS
Head and neck cancer patients in Ontario, Canada, who underwent a resection confirmed by both hospital-level and physician-level administrative data between 1993 and 2010, comprised our cohort (N = 5,720). Physician and hospital volumes were calculated based on number of cases performed in the year prior by the physician and at an institution performing each case, respectively. A multilevel hierarchical Cox regression model was used to estimate the effect on overall survival of each 25 increase in procedure volume.


RESULTS
A crude model without patient or treatment characteristics demonstrated that both surgeon volume (hazard ratio [HR]: 0.927, 95% confidence interval [CI]: 0.879-0.978, P = .006) and hospital volume (HR: 0.980, 95% CI: 0.970-0.991, P = .0003) were associated with improved overall survival. After controlling for clustering and patient/treatment covariates, hospital volume (HR: 0.976, 95% CI: 0.955-0.997, P = .02), but not physician volume (HR: 1.042, 95% CI: 0.941-1.155, P = .43), remained a statistically significant predictor of overall survival. This translates into a 2.4% decrease in the HR for every 25 additional cases performed at an institution.


CONCLUSIONS
Both high-volume surgeons and hospitals are predictors of better overall survival in head and neck cancer patients. However, the effect is largely explained by hospital volume. This benefit, at the institution level, could potentially be explained by important processes of care that contribute to overall survival.
Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, Ontario, Canada.
Antoine
A
Eskander
Jonathan
J
Irish
Patti A
PA
Groome
Jeremy
J
Freeman
Patrick
P
Gullane
Ralph
R
Gilbert
Stephen F
SF
Hall
David R
DR
Urbach
David P
DP
Goldstein
D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000601:surgery*; D003695:Delivery of Health Care; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality* / Q000601:surgery*; D061847:Hospitals, High-Volume / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck; D013514:Surgical Procedures, Operative / Q000706:statistics & numerical data*; D015996:Survival Rate; D016896:Treatment Outcome; D019472:Universal Health Insurance
Head and neck cancer; clinical epidemiology; health services research; hospital volume; outcomes research; surgeon volume