1 An overview of manageable preanalyti- cal factors XXX Nordic Congress in Clinical Biochemistry  Copenhagen  Ulrik Gerdes Klinisk Biokemisk Laboratorium ∙ Center for Psykiatrisk Grundforskning ∙ Risskov

2 Contents Is the importance of preanalytical factors coming (back) into focus? What can preanalytical factors do to your results? An overview of preanalytical factors Which are manageable? Questions

3 Preanalytical factors (back) in focus? It appears so, at least in Denmark Total ‘measurement uncertainty budgets’ bring the importance of preanalytical factors into focus The lack of standards (consensus) appear increasingly odd in an otherwise standardized world Demands for efficiency and low-budget solutions often strain professional considerations for ‘the preanalytical phase’

4 Example :: Resting before blood sampling?

5 Effects of preanalytical factors Important determinants of some biochemical variables Increases total variation, i.e. the coverage interval for measurement results Can cause bias, i.e. systematic deviations of measurement results Can cause blunders, i.e. severe measurement errors

6 Overview of preanalytical factors Ungovernable factors :: the reality of life :: Ungovernable, but manageable factors :: standardize :: Manageable factors :: technical stuff ::

7 Manageable preanalytical factors Sampling what  how »Metabolic standardization« fasting  resting smoking  medicine Time of the day time Posture supine  sitting Tubes etc. which Processing centrifugation  etc. Transportation how  for how long Storing how  for how long

8 Thank you for your attention!

9 Questions?