My colleague and I sang the praises of error grids as a way to specify performance – for any assay. To recall, here are some of the benefits:
- Unlike most specifications, the limits can change with concentration
- Unlike most specifications, the limits need not be symmetrical
- Most specifications have one set of limits, implying that results within limits cause no harm and results outside of limits cause harm. Error grid have multiple sets of limits – called zones – whereby harm can be none, minor, or major.
- Error grid zones account of 100% of the results – they cover the XY space of candidate assay vs reference assay. Most specifications cover 95% or 99% of results, leaving the balance unspecified.
Krouwer JS and Cembrowski GS Towards more complete specifications for acceptable analytical performance – a plea for error grid analysis. Clinical Chemistry and Laboratory Medicine, 2011;49:1127-1130.