Perseveration of Laboratory Test Ordering: A Syndrome Affecting Clinicians

Why do physicians order laboratory tests? Wertman and co-workers, in one of the few large studies of this question, reported that diagnosis, monitoring, and screening were most frequent, with responses of 37, 33, and 32, respectively.1Other reasons cited were previous abnormal result (12%), prognosis (7%), education (2%), and medicolegal (1%). I have performed a less sophisticated but more wide ranging study of the same question during the past five years. Groups of physicians and laboratory workers in various states and countries have been challenged verbally with the question "Why do physicians order laboratory tests?" Remarkable similarities and a few sharp differences in responses between various groups have appeared. The reasons offered include the following: A classic example of physicians ordering laboratory tests for reasons other than appropriate is the so-called CBC. It is common for a CBC to be ordered repetitively without a rational basis, such as in