Definitions
Test purpose:
Intended use of the test.
Assay format: The technique on which the test is generally based, e.g. immunoassay, nucleic acid test.
Specimen type: The types of specimens that can be used for the test. Although all validated specimen types are listed for each test category, not all tests on the market are validated for all specimen types. Users are requested to always follow the manufacturer’s instructions for specimen preparation and storage.
Specimen type: The types of specimens that can be used for the test. Although all validated specimen types are listed for each test category, not all tests on the market are validated for all specimen types. Users are requested to always follow the manufacturer’s instructions for specimen preparation and storage.
WHO prequalified or recommended products: For each test for which there are name brand products either prequalified or otherwise recommended by WHO, a link is provided.
WHO supporting documents: If there is WHO guidance on use of the test category, a link is provided to the appropriate site on the WHO website.
Screening test:1 Screening tests are used to determine the status of a disease, disorder or other physiological state in an asymptomatic individual. Depending on the nature of the condition and the targeted patient population, screening tests may be used routinely or may be restricted to ‘at risk’ patients. These tests are designed to evaluate an individual’s current state.
Diagnostic test:1 Diagnostic tests are used to determine, verify or confirm a patient’s clinical condition as a sole determinant. This type of testing also includes sole confirmatory assays (to verify results of previous testing) and sole exclusion assays (to rule out a particular condition). These tests are designed to evaluate a patient’s current state.
Aid to diagnosis:1 Tests that are used as aids to diagnosis provide additional information to assist in the determination or verification of a patient’s clinical status. The test is not the sole determinant. These tests are designed to evaluate a patient’s current state.
Monitoring test:1 Monitoring tests are used for measuring levels of analytes for the purpose of adjusting treatments or interventions as required. Monitoring tests include:
Prediction:1 Predictive tests are used to measure factors that determine the likelihood of patient responses or adverse reactions to a specific therapy. Predictive tests designed specifically for use with a targeted therapy are sometimes termed ‘companion diagnostics’ or ‘personalized medicine’. These tests are designed to evaluate a patient’s future state.
Determination of Physiological Status:1 Physiological status determination tests are used to evaluate the physiological state of an individual for the purpose of identifying a human condition or characteristic. These tests are designed to evaluate a patient’s current state.
Surveillance test: Performed on populations of interest to track the progression of disease incidence and/or prevalence.
Staging tests: Performed on patients with a confirmed disease or condition to determine its state at the time of diagnosis and establish a baseline to make relevant treatment decisions.
Essential diagnostics: Essential diagnostics are those that satisfy the priority health care needs of the population and are selected with due regard to disease prevalence, public health relevance, evidence of utility and accuracy and comparative costeffectiveness.
In vitro diagnostics:2 In vitro diagnostics are a subset of medical devices. They are defined as devices which, whether used alone or in combination, are intended by the manufacturer for the in-vitro examination of specimens derived from the human body solely or principally to provide information for diagnosis or monitoring for compatibility purposes. They include reagents, calibrators, control material and test kits.
Medical devices:2 A medical device is any instrument, apparatus, implement, machine, appliance, implant, reagent for in vitro use, software, material or other similar or related article, intended by the manufacturer to be used, alone or in combination, for human beings, for one or more of the specific medical purpose(s) of:
Assay format: The technique on which the test is generally based, e.g. immunoassay, nucleic acid test.
Specimen type: The types of specimens that can be used for the test. Although all validated specimen types are listed for each test category, not all tests on the market are validated for all specimen types. Users are requested to always follow the manufacturer’s instructions for specimen preparation and storage.
Specimen type: The types of specimens that can be used for the test. Although all validated specimen types are listed for each test category, not all tests on the market are validated for all specimen types. Users are requested to always follow the manufacturer’s instructions for specimen preparation and storage.
WHO prequalified or recommended products: For each test for which there are name brand products either prequalified or otherwise recommended by WHO, a link is provided.
WHO supporting documents: If there is WHO guidance on use of the test category, a link is provided to the appropriate site on the WHO website.
Screening test:1 Screening tests are used to determine the status of a disease, disorder or other physiological state in an asymptomatic individual. Depending on the nature of the condition and the targeted patient population, screening tests may be used routinely or may be restricted to ‘at risk’ patients. These tests are designed to evaluate an individual’s current state.
Diagnostic test:1 Diagnostic tests are used to determine, verify or confirm a patient’s clinical condition as a sole determinant. This type of testing also includes sole confirmatory assays (to verify results of previous testing) and sole exclusion assays (to rule out a particular condition). These tests are designed to evaluate a patient’s current state.
Aid to diagnosis:1 Tests that are used as aids to diagnosis provide additional information to assist in the determination or verification of a patient’s clinical status. The test is not the sole determinant. These tests are designed to evaluate a patient’s current state.
Monitoring test:1 Monitoring tests are used for measuring levels of analytes for the purpose of adjusting treatments or interventions as required. Monitoring tests include:
- Assays which are used to ensure that an analyte remains within physiological levels or within an established therapeutic drug range. These types of monitoring tests are designed to evaluate an individual’s current state.
- Assays which are used for serial measurement, whereby multiple determinations are taken over time. These types of monitoring tests are typically used for the detection/assessment of disease progression/regression, disease recurrence, minimum residual disease, response/resistance to therapy, and/or adverse effects due to therapy. These types of monitoring tests are designed to evaluate changes in an individual’s state.
Prediction:1 Predictive tests are used to measure factors that determine the likelihood of patient responses or adverse reactions to a specific therapy. Predictive tests designed specifically for use with a targeted therapy are sometimes termed ‘companion diagnostics’ or ‘personalized medicine’. These tests are designed to evaluate a patient’s future state.
Determination of Physiological Status:1 Physiological status determination tests are used to evaluate the physiological state of an individual for the purpose of identifying a human condition or characteristic. These tests are designed to evaluate a patient’s current state.
Surveillance test: Performed on populations of interest to track the progression of disease incidence and/or prevalence.
Staging tests: Performed on patients with a confirmed disease or condition to determine its state at the time of diagnosis and establish a baseline to make relevant treatment decisions.
Essential diagnostics: Essential diagnostics are those that satisfy the priority health care needs of the population and are selected with due regard to disease prevalence, public health relevance, evidence of utility and accuracy and comparative costeffectiveness.
In vitro diagnostics:2 In vitro diagnostics are a subset of medical devices. They are defined as devices which, whether used alone or in combination, are intended by the manufacturer for the in-vitro examination of specimens derived from the human body solely or principally to provide information for diagnosis or monitoring for compatibility purposes. They include reagents, calibrators, control material and test kits.
Medical devices:2 A medical device is any instrument, apparatus, implement, machine, appliance, implant, reagent for in vitro use, software, material or other similar or related article, intended by the manufacturer to be used, alone or in combination, for human beings, for one or more of the specific medical purpose(s) of:
- diagnosis, prevention, monitoring, treatment or alleviation of disease;
- diagnosis, monitoring, treatment, alleviation of or compensation for an injury;
- investigation, replacement, modification or support of the anatomy or of a physiological process, supporting or sustaining life;
- control of conception;
- disinfection of medical devices; or
- providing information by means of in vitro examination of specimens derived from the human body;
References
- Clinical evidence for IVD medical devices – clinical performance studies for in vitro diagnostic medical devices. Study group 5 final document GHTF/ SG5/N8:2012. International Medical Device Regulators Forum; 2012 (link, accessed May 2019).
- Definition of the Terms ‘Medical Device’ and ‘In Vitro Diagnostic (IVD) Medical Device’ Study Group 1 Final Document GHTF/SG1/N071:2012 (link, accessed May 2019).