The role of the laboratory is to produce results that will be used by clinicians to diagnose disease and monitor response to treatment, but a key issue that is now becoming more apparent is that over ordering of tests can actually lead to patient harm . Inappropriate investigations or treatments which can be invasive may follow results that are imprecise. Clinicians also need sufficient information to identify true change in the patient. For laboratories to reduce the likelihood of these poor outcomes they need to understand not just the imprecision of their assays, but also the variation introduced by collection, biological variation and disease and to communicate these to the clinicians. Laboratory staff must understand not only when to suggest a test may be useful in the differential diagnosis but also when a test should not be repeated because the test results will not be able to be interpreted .
Available at: http://works.bepress.com/tony_badrick/7/