Redundancy of Result Verification

Having worked in a medical diagnostic lab all this while, I still don’t understand the point of result verification. For those of you not in the scientific field, when a test (for glucose or calcium levels in a blood sample for example) is done, the standard operating procedure (SOP) is if the result is normal (i.e. falls within normal human range), the result is accepted. But if the result is abnormal, the test has to be repeated to check for its validity.

Now here’s the part I don’t understand. Why do you doubt an abnormal result but gladly accept a normal one without any further investigation? Over-optimism, perhaps? A normal result has just the same chance of being false as an abnormal one.

Another thing that makes the whole procedure pointless is that in a lab, everyone wants perfect results. So let me give you a scenario of what happens in a lab (based on one of my true experiences). A glucose test is abnormally high, 340 mg/dl. The normal human glucose range is 50 – 300 mg/dl. So I repeat the test using a different machine. This is to check if the result was affected by machine error. The result comes out as 298 mg/dl. Yay, the machine was wrong and the patient is normal!

But wait, the supervisor says, “No, that can’t be right. Repeat it until you get the same results as the first test.” In conculsion, there are only two outcomes to repeating a test. Either you get back the same result, rendering the entire affair a waste of time, energy and reagents (which aren’t cheap), or you get a different result and your supervisor tells you to repeat it over until you get the same result, leading to… the same result, loss of time, energy and reagents and in addition a lecture from your supervisor.

If everyone wants an unchanging result, what’s the point of result verification? Why not just release the original result? But no, there’s the SOP. *sigh* The whole system is broken.

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