Variability and determining the significance of changes in measurements over time are discussed in this second article in a series of four aiming to provide a framework for interpreting test results.
Random variability in pathology results needs to be minimised so that real change can be identified when results of sequential tests differ. As well as a difference being statistically significant it also needs to be clinically significant to prompt medical intervention.
This second article in a series of four outlining a framework for interpreting laboratory results focuses on variability. It discusses the source of variability between sequential laboratory measurements of the same variable within the same individual and discusses ways to minimise the background ‘noise’ of random variability, maximise the ‘signal’ of any biological change and interpret the significance of changes in measurements over time.
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