Table 2 Criteria for evaluating multivariate index assays

1.

Normal control and disease control groups used to generate the index should be matched demographically (age, gender, race, and geography) with the target group.

2.

Pre-analytical variables (specimen type, specimen handling, and specimen storage) should be equivalent in control and diseased groups.

3.

There should be a high ratio of subjects (patients) to measured analytes used to generate the index.

4.

The accuracy (clinical sensitivity and specificity) of the index test should be tested and reported on the basis of populations of subjects (the 'test set' of diseased patients and controls) independently of the subjects (the 'training set') used to generate the index formulae or calculations.

5.

The clinical accuracy (clinical sensitivity and specificity) of the index test should be compared with the accuracy of the most accurate of the individual analytes within the index or with the best available single diagnostic laboratory test or both.