The NICE Glossary provides brief definitions and explanations of terms used on our site. The terms describe how we work and how our 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.

  • Health economics

    Study or analysis of the cost of using and distributing healthcare resources.
  • Health gain

    A measured improvement in the health of a person or a population.
  • Health impact assessment

    A combination of procedures, methods and tools used to judge a policy, programme or project. For example, a health impact assessment could be used to determine how a proposal for a new road or new airport runway will affect local people's health. The process involves: gathering information on the areas and communities affected and using various tools to predict how it will impact on health; evaluating the options; and making recommendations to ensure any potential harm is minimised or opportunities to improve health are maximised. Other similar procedures include strategic environmental assessment, sustainability appraisal and environmental impact assessment.
  • Health inequalities

    Health inequalities relate to differences in health state or status between individuals or groups. These differences could be measured in terms of, for example, socioeconomic group, men and women, ethnic groups or geographical communities. Health inequalities may be partly biological in origin but may also be the consequence of human activity. If inequalities arise as a consequence of human actions, they can be changed if the causes are changed. See also health inequities.
  • Health inequities

    A health inequity is an unnecessary, avoidable, unfair and unjust difference between the health or healthcare of 1 person, and that of another.
    'Health inequity' should not be used interchangeably with the term 'health inequality' because the differences in health or healthcare that people experience are not necessarily unfair or unjust. Health inequity is concerned with social justice, values or politics, while inequalities in health are a matter of fact. Addressing them can have considerable political implications because of the value judgement involved: not all people will judge the same health difference to be unfair.
  • Health needs assessment

    A systematic process used by NHS organisations and local authorities to assess the health problems facing a population. This includes determining whether certain groups appear more prone to illness than others and pinpointing any inequalities in terms of service provision. It results in an agreed list of priorities to improve healthcare in a particular area.
  • Health promotion

    Giving people the information or resources they need to improve their health. As well as improving people's skills and capabilities, it can also involve changing the social and environmental conditions and systems that affect health.
  • Health status

    How healthy a person, group, or population is. This could be assessed by the person or group concerned or by using more objective measures. The judgement is usually based on the person's ability to carry out everyday activities and how free they are from pain.
  • Health technology

    Drugs, medical devices (such as artificial hip joints), diagnostic techniques, surgical procedures and other treatments to improve health or prevent ill health.
  • Heterogeneity

    The term is used in meta-analyses and systematic reviews to describe when the results of a test or treatment (or estimates of its effect) differ significantly in different studies. Such differences may occur as a result of differences in the populations studied, the outcome measures used or because of different definitions of the variables involved. It is the opposite of homogeneity.
  • Hierarchy of evidence

    Study types organised in order of priority, based on the reliability (or lack of potential bias) of the conclusions that can be drawn from each type. See also Levels of evidence.
  • Homogeneity

    A term used in meta-analyses and systematic reviews to indicate that the results of studies are similar; the opposite of heterogeneity. Study results are also regarded as homogeneous if any differences could have occurred by chance.
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