Managing laboratory test ordering through test frequency filtering.

Background: Modern computer systems allow limits to be set on the periods allowed for repetitive testing. We investigated a computerised system for managing potentially overtly frequent laboratory testing, calculating the financial savings obtained.

Methods: In consultation with hospital physicians, tests were selected for which 'spare periods' (periods during which tests are barred) might be set to control repetitive testing. The tests were selected and spare periods determined based on known analyte variations in health and disease, variety of tissues or cells giving rise to analytes, clinical conditions and rate of change determining analyte levels, frequency with which doctors need information about the analytes and the logistical needs of the clinic.

Results: The operation and acceptance of the system was explored with 23 analytes. Frequency filtering was subsequently introduced for 44 tests, each with their own spare periods. The proportion of tests barred was 0.56%, the most frequent of these being for total cholesterol, uric acid and HDL-cholesterol. The financial savings were 0.33% of the costs of all testing, with HbA1c, HDL-cholesterol and vitamin B12 yielding the largest savings. Following the introduction of the system the number of barred tests ultimately decreased, suggesting accommodation by the test requestors.

Conclusions: Managing laboratory testing through computerised limits to prevent overtly frequent testing is feasible. The savings were relatively low, but sustaining the system takes little effort, giving little reason not to apply it. The findings will serve as a basis for improving the system and may guide others in introducing similar systems.