Table 2.
Definitions of common terms used in the analytical validation and clinical validation steps.
| Terms | Definitions |
|---|---|
| Analytical Validation | |
| Accuracy | Agreement between a test result of a quantity and its reference value |
| Repeatability | Describes test results performed under the same conditions |
| Reproducibility | Describes test results performed under different conditions |
| Analytical Sensitivity | The ability of the assay to obtain a concordance in positive results between assay and reference method |
| Analytical Specificity | The ability of the assay to obtain a concordance in negative results between assay and reference method |
| Linearity | The ability of the assay to yield a proportional effect between test values and concentrations of the analyte in the sample |
| Limit of Detection | The lowest concentration of analyte significantly different from zero or negative control |
| Robustness | Test precision following deliberate changes in assay conditions (temperature, storage, etc.) |
| Clinical Validation | |
| Clinical Sensitivity | Ability of a biomarker to predict a change in a clinical endpoint (relationship between the magnitude of change in the biomarker and the magnitude of change in the clinical endpoint) |
| Clinical Specificity | Ability of a biomarker to distinguish responders and NR patients in terms of changes in clinical endpoints |
| Relative Risk | Ratio of the probability of an event (e.g., disease recurrence, death) occurring in the treated group to the probability of the event occurring in the control group |