One of two controls that have been evaluated over the last 28 days gives a result on day 29 between 2 and 3 SDs of the mean;the other control is within 2 SDs of its mean.What is the correct procedure to follow?
A)Ignore the result unless it happens again the next day.
B)Rerun the control and, if acceptable, continue with patients.
C)Recalibrate the instrument.
D)Open new vials of controls and repeat both controls.

Question

Quizplus · Accepted Answer

One control is acceptable,whereas the other is a warning that the method may be going out of control.The test option in this case is to repeat the analysis of the control,and if it is acceptable,continue with patient analysis,reporting the results.The instrument does not appear to need recalibration because one control is acceptable and the other is within 3 SDs (1 result of 20 can acceptably be within ±3 SDs).If the repeat on the "out of control" vial is still out between 2 and 3 SDs,then a new vial of that control should be opened and analyzed.The control that was acceptable does need to be repeated.

One of Two Controls That Have Been Evaluated Over the Last