The annual review of internal QC is performed to answer two questions:
- What is the quality (random and systematic effects) currently in the laboratory? Has the quality significantly changed?
- Are control limits and central line in the control chart still optimal for detecting situations out of control?
Guidance for this is difficult to give but a general approach is given in the Trollbook (Nordtest TR569) chapter 10 and in example 8 is presented in detail the statistical calculations
In the annual review you should also look at your PT data.