Analytical goals for haematology tests.

Area of Science:

• Clinical chemistry
• Analytical methodology
• Laboratory medicine

Background:

• Analytical methods require defined performance standards, including goals for imprecision and inaccuracy.
• Various approaches exist for setting these analytical goals, such as reference values and clinician opinions.
• Data on biological variation is increasingly favored for establishing desirable performance standards.

Purpose of the Study:

• To define desirable analytical goals for laboratory testing performance.
• To evaluate the use of biological variation for setting imprecision and inaccuracy targets.
• To assess the impact of analytical variability on total test result variability.

Main Methods:

• Reviewing methods for setting imprecision goals, including biological variation.
• Proposing goals for inaccuracy based on minimizing bias for temporal and geographical comparability.
• Considering goals for total error derived from biological variation data.

Main Results:

• Desirable imprecision is set at or below half of the within-subject biological variation.
• Achieving this imprecision goal limits analytical contribution to total test variability to under 10%.
• Valid estimates of within-subject biological variation exist for complete blood count parameters.
• Inaccuracy goals aim for methods with no bias, ensuring result comparability.

Conclusions:

• Biological variation provides a robust framework for setting analytical goals for imprecision and total error.
• Current analytical methods may not meet all desirable goals, highlighting them as targets for improvement.
• Analytical goals should serve as aspirational targets rather than strict acceptance criteria for method validation.