Elsevier

Urology

Volume 69, Issue 5, May 2007, Pages 871-875
Urology

Adult urology
Volume, Process of Care, and Operative Mortality for Cystectomy for Bladder Cancer

https://doi.org/10.1016/j.urology.2007.01.040Get rights and content

Objectives

High-volume hospitals have lower mortality rates for a wide range of surgical procedures, including cystectomy for bladder cancer. However, the processes of care that mediate this effect are unknown. We sought to identify the processes that underlie the volume-outcome relationship for cystectomy.

Methods

Within the Surveillance, Epidemiology, and End Results (SEER)-Medicare data set, we used International Classification of Diseases (ICD)-9 procedure codes to identify 4465 patients who underwent cystectomy for bladder cancer between 1992 and 1999. The preoperative and perioperative processes of care were abstracted from the inpatient, outpatient, and physician files using the procedure and diagnosis codes available through 2002. Logistic models were used to assess the relationship between the process and hospital volume, adjusting for differences in patient characteristics.

Results

Substantial variation was found in the use of specific processes of care across the hospital volume strata. High-volume hospitals had greater rates of preoperative cardiac testing (odds ratio [OR] 1.57, 95% confidence interval [CI] 1.24 to 1.98), intraoperative arterial monitoring (OR 3.73, 95% CI 3.11 to 4.46), and the use of a continent diversion (OR 4.01, 95% CI 3.03 to 5.30), among many others. Patients treated at low-volume hospitals were 48% more likely to die in the postoperative period (4.9% versus 3.5%, adjusted OR 1.48, 95% CI 1.03 to 2.13). Differences in the use of processes of care explained 23% of this volume-mortality effect.

Conclusions

High-volume and low-volume hospitals differ with regard to many processes of care before, during, and after radical cystectomy. Although these practices have partly explained the volume-outcome relationships for cystectomy, the primary mechanisms underlying this effect remain unclear.

Section snippets

Subjects

Incident bladder cancer cases diagnosed from 1992 to 1999 in patients aged 65 to 99 years were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare files. The demographic composition, as well as the cancer incidence and mortality trends, of the SEER registry is considered representative of the entire U.S. population.10 For each Medicare patient within SEER, the SEER-Medicare linked files contain 100% of inpatient (part A) and outpatient and physician (part B) claims.

Results

From 1992 to 1999, 4465 patients were treated with partial (n = 1375, 30.8%) or radical (n = 3090, 69.2%) cystectomy for bladder cancer within the SEER-Medicare database. Differences in patient characteristics for low, medium, and high-volume hospitals are given in Table 1. In general, high-volume hospitals treated a slightly younger patient population and a greater proportion of blacks. Although patients had a similar cancer stage distribution across the hospital volume strata, those treated

Comment

After adjusting for differences in health status and disease severity, patients treated at low-volume hospitals were nearly 50% more likely to die in the postoperative period. We observed substantial disparities in the use of processes of care by hospital volume for all phases of patient care. With regard to most processes, high-volume hospitals had substantially greater rates of use, exhibiting a more intensive practice style overall. Cumulatively, these processes had a moderate effect in

Conclusions

This study is among the first to suggest differences in processes of care according to hospital volume. These differences explain some, but not all, of the volume-mortality effect among patients undergoing cystectomy for bladder cancer. Ultimately, the exportation of processes of care identified at high-volume to low-volume hospitals might be the most practical means of reducing the variation in mortality rates across hospitals.

References (17)

There are more references available in the full text version of this article.

Cited by (0)

The views expressed herein do not necessarily represent the views of Center for Medicare and Medicaid Services or the United States Government.

This study was supported by the National Cancer Institute (1 R01 CA098481-01A1).

View full text