The effect of hospital volume on mortality and resource use after radical prostatectomy

PURPOSE: The value of radical prostatectomy for patients with prostate cancer depends on low morbidity and mortality. We assessed whether patient outcome is associated with how many of these procedures are performed at hospitals yearly. MATERIALS AND METHODS: Using the Nationwide Inpatient Sample, which is a stratified probability sample of American hospitals, we identified 66,693 men who underwent radical prostatectomy between 1989 and 1995. Cases were categorized into volume groups according to hospital annual rate of radical prostatectomies performed, including low-fewer than 25, medium-25 to 54 and high-greater than 54. We performed multivariate logistic regression to control for patient characteristics when assessing the associations of hospital volume, in-hospital mortality and resource use. RESULTS: Overall adjusted in-hospital mortality after radical prostatectomy was relatively low (0.25%). However, patients at low volume centers were 78% more likely to have in-hospital mortality than those at high volume centers (adjusted odds ratio 1.78, 95% confidence interval 1.7 to 2.6). Overall length of stay decreased at all hospitals between 1989 and 1995. However, average length of stay was longer and total hospital charges were higher at low than at high volume centers (7.3 versus 6.1 days, p<0.0001, and $15,600 versus $13,500, p<0.0001, respectively). CONCLUSIONS: Hospital volumes inversely related to in-hospital mortality, length of stay and total hospital charges after radical prostatectomy. Further study is necessary to examine the association of hospital volume with other important outcomes, including incontinence, impotence and long-term patient survival after radical prostatectomy.