Although there is nearly universal agreement that laboratory tests are overutilized, the degree of overutilization in a given institution is difficult to quantify and monitor across time.
To detect and clearly document repetitive daily ordering of a commonly ordered laboratory test (serum sodium) by employing a simple, focused, computerized query of a test result database followed by chart review and validation.
A retrospective computerized query of our clinical data repository was performed to find inpatients who displayed normal serum sodium test results on 4 or more consecutive days, without any abnormal values during the same admission. The search was limited to a 1-month period. A subset of these patients was selected for chart review.
One hundred sixteen patients met our criteria, and the tests ordered for those patients comprised 5.1% of the monthly volume of serum sodium tests ordered in our institution. Chart review revealed a consistent lack of documentation of medical necessity for repeat testing as well as persistence of repeat serum sodium orders until the end of the patients' hospital course.
We conclude that a focused query of data derived from a clinical data repository can detect and document overutilization of a common laboratory test in a convincing fashion within a given institution.