Effect of Hospital Volume on Operative Mortality for Major Cancer Surgery

Abstract & Commentary

Synopsis: Major cancer surgery appears to be safer at hospitals that perform a high volume of cases.

Source: Begg CB, et al. JAMA 1998;280:1747-1751.

Various studies in the past have indicated that hospitals that perform complex surgical procedures for cancer, but perform only a small volume of these procedures, have poorer outcomes than hospitals that treat more cases. One of the major limitations to these past studies has been the fact that they have used hospital mortality and/or days of hospitalization as their end points. Because discharge practices vary greatly, these studies might miss deaths that are clearly related to surgery but occurred after discharge.

Begg and colleagues attempted to circumvent the problem of using hospital discharge diagnoses by using the Surveillance Epidemiology and End Results (SEER)-Medicare database. By using this source of information, they were able to examine mortality occurring within 30 days following hospital admission. The major weakness of their study was the fact that all cases were 65 years of age or older.

Begg et al restricted their analyses to five procedures: Pancreatectomy, esophagectomy, pneumonectomy, hepatectomy, and pelvic exenteration. They used appropriate coding procedures using the ICD-9-CM classification system. Appropriate statistical analyses were performed. The time period of interest was 1984-1993.

The results were largely consistent with previously published studies. Specifically, Begg et al found that hospitals performing a larger volume of these complicated procedures had lower mortalities. The only exception was pneumonectomy where the difference between mortality at the low- and high-volume hospitals did not meet the criterion for statistical significance.

A co-morbidity case mix study did not identify this as a reason for the observed difference, though Begg et al found co-morbidity to be a difficult subject to study.

Comment by Kenneth Noller, MD

I believe this is an important paper (and, apparently, the JAMA editorial board also had the same thought since an editorial accompanies the article). Yet, the results are so "common sense" it almost seems ridiculous to study it. Why wouldn’t surgeons at a hospital that performs several pelvic exenterations a year be better and have less mortality than a hospital that performed only one such procedure in a decade? Nonetheless, 112 hospitals did exactly that (i.e., performed 1 pelvic exenteration during the entire study decade).

Few would argue with the conclusion of this study since it dealt with complex procedures. However, I think it is important for each of us to constantly evaluate our own abilities and limitations. Clearly, there are many conditions we were familiar with during our days in resident training that we now only see rarely, if at all. Referral to an appropriate subspecialist—at a facility that performs a large volume of the evaluation/procedures—is clearly desirable.

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