The NICE glossary provides brief definitions and explanations of terms used on the website. The terms describe how NICE works and how its guidance is produced.

Our glossary excludes specific clinical and medical terms. If you cannot find the term you are looking for, please email us so that we can consider adding it to the glossary.

Some definitions and examples are based on those in the HTAi consumer and patient glossary, with thanks to Health Technology Assessment International.

For terms used in social care, the Care and Support Jargon Buster from Think Local Act Personal is a useful guide to the most commonly used social care words and phrases, and what they mean.

  • Negative predictive value

    The proportion of people with a negative test result who do not have the disease or characteristic. It is different from specificity.

  • Net benefit

    The value of the benefit from a test, treatment or procedure, minus its total costs. It can be expressed in health (for example, using quality-adjusted life years) or monetary terms.

  • Net health benefit

    The difference between the total expected quality-adjusted life years and the health expected to be forgone elsewhere (these are the total expected costs divided by the maximum acceptable incremental cost-effectiveness ratio value).

  • Net monetary benefit

    The difference between the monetary value of total expected quality-adjusted life years (QALYs) and total expected costs. Total expected QALYs are calculated by multiplying expected QALYs by the maximum acceptable incremental cost-effectiveness ratio value.

  • Network meta-analysis

    An analysis that compares 2 or more interventions using a combination of direct evidence (from studies that directly compare the interventions of interest) and indirect evidence (from studies that do not compare the interventions of interest directly).

  • NICE Accreditation Programme

    A programme that assesses the processes organisations use to produce guidance and advice. Organisations that use robust and transparent processes can display an accreditation mark on their guidance, so that health and social care practitioners know it is of high quality. Accredited guidance may be used to develop NICE quality standards.

  • NICE advice

    NICE products that update healthcare, public health and social care practitioners on new evidence, or help put NICE guidance into context. They do not contain recommendations. Examples of NICE advice include local government briefings, evidence summaries - new medicines, and evidence summaries - unlicensed and off-label medicines.
  • NICE Endorsement Programme

    A programme that endorsed resources to support our guidance, which were produced by other organisations. The programme closed at the end of March 2022.

  • NICE Evidence Services

    Online services that enable access to authoritative clinical and non-clinical evidence and best practice to help people from across the NHS, public health and social care sectors make better decisions. The service also works directly with professionals and practitioners to identify evidence, and to support the uptake and use of evidence to improve practice and care for people using services.
  • NICE Fellows and Scholars Programme

    Fellowships and scholarships are unpaid posts that allow NHS health and social care professionals to work with NICE for their own professional development, and to help improve the quality of care in their local areas. NICE fellows and scholars are ambassadors for clinical, social care and public health excellence, and promote the principles and recommendations of NICE guidance in their own specialty or discipline.

    NICE fellowships are non-renewable 3-year posts for senior health professionals or managers.

    NICE scholarships typically last for 1 year and are designed to support professional development and contribute towards a formal qualification or training programme.

  • NICE field team

    A team of 8 implementation consultants who work with organisations to help to put NICE guidance into practice. Each consultant works with NHS, local authority and other organisations in their area, ensuring regular interaction with NICE stakeholders.

  • NICE guidance

    Evidence-based recommendations produced by NICE. There are 6 types of guidance:

    • guidelines covering clinical topics, medicines practice, public health and social care
    • diagnostics guidance
    • highly specialised technology guidance
    • interventional procedures guidance
    • medical technologies guidance
    • technology appraisals guidance.

    All guidance is developed by independent committees and is consulted on. NICE may also publish a range of supporting documents for each piece of guidance, including advice on how to put the guidance into practice, and on its costs, and the evidence it is based on.

    See also NICE advice.

  • NICE Medicines and Prescribing Programme

    Supports and promotes high-quality, safe, cost-effective prescribing and medicines optimisation within local health economies. Among other things, it produces evidence summaries: new medicines, evidence summaries: unlicensed and off-label medicines, evidence summaries: medicines and prescribing briefings, key therapeutic topics and supports the Medicines and Prescribing Associates Programme.

  • Nominal group technique

    A technique used to reach agreement on a particular issue. It uses a variety of postal and direct contact techniques, with individual judgements being aggregated statistically to derive the group judgement
  • Non-randomised study

    A comparative study which does not involve randomisation. This can include purely observational studies, non-randomised interventional studies, and single-arm trials with external control.

  • Non-reference-case analysis

    An analysis that does not use the methods in the reference case.

  • Notification

    The process by which a notifier (usually the manufacturer of the medical technology) informs NICE about a potential technology for evaluation.

  • Number needed to harm

    A measure of the chance of experiencing a specified harm in a specified time because of the treatment or other intervention. Ideally, this number should be as large as possible. For example, if the number needed to harm (NNH) for drug A compared with drug B for major bleeding over 1 year is 50, on average, for every 50 people who take drug A instead of drug B for 1 year, 1 person will have major bleeding who would not have done if all 50 had got drug B. The other 49 people out of the 50 will have or not have major bleeding, just as if they had taken drug B. The NNH is 100 divided by the absolute risk increase (ARI) expressed as a percentage. For example, if the ARI is 0.1%, the NNH is 100/0.1=1,000.

  • Number needed to treat

    The average number of patients who need to havethe treatment or other intervention for one of them to get the positive outcome in the time specified. The closer the number needed to treat (NNT) is to 1, the more effective the treatment. For example, if the NNT for drug A compared with drug B for pain relief after a tooth extraction is 4, on average, for every 4 people who get drug A instead of drug B, 1 person will have pain relief after tooth extraction who would not have done if all 4 had got drug B. The other 3 people out of the 4 will have or not have pain relief, just as if they had taken drug B. The NNT is 100 divided by the absolute risk reduction (ARR) expressed as a percentage. For example, if the ARR is 5%, the NNT is 100/5=20.