We have identified at least 35 reasons why physicians order laboratory tests.1 Many of them are applicable in explaining why the vast majority of hospitals and physicians in this country perform routine preoperative laboratory tests. These reasons include the following: screening, peer pressure, personal reassurance, ease of performance with ready availability, hospital policy, medical-legal need, documentation, hospital profit, curiosity, insecurity, habit, and to establish a baseline.
Elsewhere in this issue, Kaplan and colleagues from San Francisco2 report on a major, comprehensive, retrospective study of preoperative laboratory tests performed on patients admitted to their teaching hospital for elective surgery. They demonstrate that in those patients for whom there were no clinical indications for such tests, the likelihood of finding any abnormality that might influence perioperative management was extremely small. Furthermore, what few abnormalities were found were not even mentioned in the progress notes or discharge summaries and seemed to have