Learning outcomes

1. Describe the brain to brain cycle, for each phase of the cycle list at least 2 errors that can occur. In which phase do we find the most errors? Which errors most often lead to patient harm?
2. Explain the relationship between biological variation and the reference range.
3. Explain the relationship between disease and cut-off value.
   1. how this relationship affects diagnostic sensitivity and specificity
   2. how it relates to the predictive values of the test
4. Explain how we obtain data to determine clinical sensitivity specificity, positive and negative predictive values? How do we determine the cut-off value?
5. Describe how you will locally establish a reference range for a selected marker. Discuss:
   1. how to define "health" for selecting a reference population.
   2. how to get a sufficient number of probands in the reference population for each subgroup (age, sex, race ...).
6. Using the example of current Ca prostate screening, explain the salient features of meaningful screening and discuss the possible drawbacks of the currently proposed approach.
7. List the components of the critical difference calculation and discuss the consequences of changing these components on the interpretation of two consecutive values of the same analyte.

Study text where you can find answers.