Test Methods Sub-Group

The InterTASC Test Methods Sub-Group is convened by members of InterTASC teams to discuss issues relating to the NICE Diagnostics Assessment Programme and methodology for the assessment of tests.


What are tests?

Medical tests are procedures which are performed for a number of reasons, such as:

  • Diagnosis: determining whether a patient has a particular disease
  • Screening: identifying patients at risk of a particular disease (often for further testing)
  • Monitoring: tracking the progress of a disease or a treatment
  • Prognosis: predicting future outcomes for a patient (e.g., survival) based on current test results

There are also many different types of tests, such as:

  • Physical examination (e.g., motor reflex testing, listening to heart and chest sounds using a stethoscope)
  • Tests of bodily fluids (e.g., blood, saliva) or tissue (e.g., examining a biopsy sample under a microscope)
  • Imaging (e.g., X-ray, CT scan, MRI)
  • Questionnaires

What makes a good test?

One test is generally better than another test if:

  • It is better at recognising disease in patients who have the disease (a more sensitive test)
  • It is better at ruling out disease in patients who don’t have the disease (a more specific test)
  • It is more reliable
  • It is less invasive or painful for patients
  • It carries lower risks of adverse events (e.g., bleeding from endoscopy)
  • It produces results quicker
  • It costs less or requires less of other healthcare resources
  • It fails to give a result less often

Policy makers


The NICE Diagnostics Assessment Programme (DAP) assesses diagnostic technologies for use in the NHS, and particularly where a new technology cannot be demonstrated to be universally similar or superior to an existing technology.

InterTASC teams participate in the NICE DAP as External Assessment Groups (EAGs). They review existing evidence on the clinical effectiveness of the technologies, often including evidence on the diagnostic accuracy of tests, and evidence on the downstream impact of testing on patient outcomes. They will also review economic evidence and usually develop a model for an economic evaluation of the tests.

EAGs produce a Diagnostics Assessment Report (DAR) for each assessment, which is then considered by a Diagnostics Advisory Committee.

National Screening Committee

The UK National Screening Committee (UK NSC) advises ministers and the NHS about population screening programmes. The screening programmes include:

  • Antenatal screening (e.g., for Down’s syndrome)
  • Newborn screening (e.g., for cystic fibrosis)
  • Child screening (e.g., for hearing)
  • Adult screening (e.g., for breast cancer)

InterTASC teams are sometimes commissioned by the NIHR HTA Programme to conduct external reviews on behalf of the UK NSC.

InterTASC test methods sub-group

Aims and objectives

The InterTASC test methods sub-group aims to improve the way medical tests are assessed for use in the NHS, to reduce the inappropriate use of tests and to support the introduction of tests which benefit patients and the NHS.

The sub-group concentrates on the process of assessment of tests as well as the methods used to assess tests.


Current activities:

  • Meetings to discuss challenges facing InterTASC groups assessing tests

The sub-group will also be involved in developing research proposals to develop methodology in the area of test assessment.