Table 1.

Glossary of Terms

Term	Definition*
Analytical validation (1)	Establishing that the performance characteristics of a test, tool, or instrument are acceptable in terms of its sensitivity, specificity, accuracy, precision, and other relevant performance characteristics using a specified technical protocol (which may include specimen collection, handling and storage procedures). This is validation of the test's, tool's, or instrument's technical performance, but is not validation of the item's usefulness.
Clinical validation (1)	Establishing that the test, tool, or instrument acceptably identifies, measures, or predicts the concept of interest;
Clinical utility (1)	The conclusion that a given use of a medical product will lead to a net improvement in health outcome or provide useful information about diagnosis, treatment, management, or prevention of a disease. Clinical utility includes the range of possible benefits or risks to individuals and populations.
Companion Diagnostic	A companion diagnostic is a medical device, often an in vitro device (IVD), which provides information that is essential for the safe and effective use of a corresponding drug or biological product.
Complementary Diagnostic** (Draft definition from FDA as presented at ASCO – 5 June 2016)	A complementary diagnostic is a test that aids in the benefit–risk decision–making about the use of the therapeutic product, where the difference in benefit–risk is clinically meaningful. Complementary IVD information is included in the therapeutic product labeling.
Enrichment	Enrichment is the prospective use of any patient characteristic, including demographic, pathophysiologic, historical, genetic, and others, to select patients for a study or to analyze patient data to obtain a study population in which detection of a drug effect is more likely than it would be in an unenriched population.
In Vitro Diagnostic (IVD)	IVD products are those reagents, instruments, and systems intended for use in the diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequelae. Such products are intended for use in the collection, preparation, and examination of specimens taken from the human body.
Premarket Approval (PMA)	Premarket approval (PMA) is the FDA process of scientific and regulatory review to evaluate the safety and effectiveness of Class III medical devices. Due to the level of risk associated with Class III devices, the FDA has determined that general and special controls alone are insufficient to assure the safety and effectiveness of Class III devices. Therefore, these devices require a PMA application (submission via modules is an option) under section 515 of the Food, Drug and Cosmetic Act to obtain marketing clearance.

^*Source: FDA.

^**As of December 2016, no formal FDA definition exists for complementary diagnostics. ASCO, American Society of Clinical Oncology.