Table 3. Study of the robustness of the method.

Recommended practice	Sigma calculation documenting the choice of total allowable error. Use of other means to assess robustness. Compare with other indicators (monitoring of IQCs, EQAs, etc.). Adjustment of series size, IQC frequency and Westgard rules with respect to Sigma data.
Acceptable practice	The level of sigma or other means of assessing robustness used only as an indicator. Lack of specific robustness assessment but management strategy for an adapted IQC (no impact on the patient).
Unacceptable practice	Does not consider the robustness of the method.
IQC – internal quality control. EQA – external quality assessment.