Diagnostics involves the process of determining the nature and circumstances of a diseased condition. A diagnostic assay is often used in clinical decision-making for an individual patient. Diagnostic assays generally fall into one of six categories:
- Assays that screen for disease in an apparently health population;
- Assays used to aid in the diagnosis of a particular disease;
- Assays that monitor a disease or the efficacy of its treatment;
- Assays that stratify risk for a particular disease;
- Assays that prognose the natural course of a disease or condition;
- Assays that predict response to a therapeutic intervention often called a ‘companion diagnostic’ .