Nearness calculation

The nearness for a single criterion is calculated using the following formula:

where:

• Xi= nearness of ithcriterion

• Δi= difference in cut values for ithcriterion

• σi= scale for ithcriterion

The overall nearness value is calculated as:

where:

When the logarithm method is applied for a particular criterion the cut values are transformed using y = log10(x+10-5) before the difference (∆ value) is calculated.

If a cut value for a particular assay cannot be calculated, for one or both assays being compared, the criterion does not contribute to the overall Nearness calculation.