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.

  • Sample

    Participants of a study recruited from part of the study's target population. If they are recruited in an unbiased way, the results from the sample can be generalised to the target population as a whole.
  • Sampling

    The way participants are selected for inclusion in a study.
  • Scientific value judgements

    NICE bases its decisions on the best available evidence. Sometimes the available evidence is not good quality or can be incomplete, so the committees involved have to make scientific value judgements and social value judgements. Scientific value judgements involve interpreting the quality, significance and relevance of all of the available scientific, technical and clinical data, including social scientific data. These judgements are used alongside the available evidence to inform recommendations.
  • Scope

    A document that describes what a piece of guidance will and will not cover. Depending on the type of guidance, organisations that are stakeholders, consultees or commentators can comment on the draft scope during a consultation period.
  • Scope consultation table

    A table of all the comments received by NICE during consultation on a scope, and responses to the comments. It is published on the NICE website with the final scope.
  • Secondary care

    Secondary care is healthcare provided in hospitals. It includes accident and emergency departments, outpatient departments, antenatal services, genitourinary medicine and sexual health clinics.
  • Semi-structured interview

    The interviewer asks a number of open-ended questions and follows up on areas of interest in response to the information given. It allows more flexibility than a structured interview, which involves asking pre-set questions.
  • Sensitivity analysis

    A form of modelling that evaluates the impact of alternative values for some of the model parameters. Often used when there is significant uncertainty about the value of the parameter.
  • Service delivery guidance

    Recommendations aimed primarily at health service commissioners. Service delivery guidance focuses on the broad configuration and provision of clinical services.
  • Shared learning award

    An award that celebrates the best examples of how organisations have put NICE guidance into practice.
  • Shared learning database

    Case studies of good practice showing how NICE guidance has been implemented. The database allows organisations to learn from each other's experience of implementing NICE guidance.
  • SIGN

    Scottish Intercollegiate Guidelines Network (SIGN). SIGN was established in 1993 to sponsor and support the development of evidence-based clinical guidelines for the NHS in Scotland.
  • Single technology appraisal

    Technology appraisal guidance, produced using a 'fast-track' process, for a single drug or treatment.
  • Single-blind study

    A study in which either the participant or the investigator does not know which treatment or intervention the participant is receiving.
  • Social care

    Care services for people who need extra help because of their age or physical or learning disabilities, and for children in need of care and protection. Examples are residential care homes for elderly people, support for people living in their own homes, and services for looked-after children.
  • Social marketing

    Using marketing principles and techniques as part of a health promotion campaign to persuade people to make a positive change in their behaviour to improve their health or prevent ill health.
  • Social value judgements

    We base our decisions on the best available evidence. Sometimes the available evidence is not of good quality or can be incomplete, so the committees involved have to make scientific value judgements and social value judgements. Social value judgements take account of society's expectations, preferences, culture and ethical principles when making recommendations. Social value judgements: principles for the development of NICE guidance sets out how committees should take into account factors such the need to distribute health resources in the fairest way within society as a whole.
  • Socioeconomic status

    Description of a person's position in society using criteria such as their occupation, income or level of education achieved.
  • Stakeholder

    An organisation with an interest in a topic that NICE is developing guidance on. Organisations that register as stakeholders can comment on the draft scope and the draft guidance. Stakeholders may be:

    • local government and utilities in England
    • NHS organisations

    • national organisations or groups of and for people who use health and social care services, their families and carers, and the public

    • organisations representing people working in health and social care

    • local Healthwatch organisations

    • public sector providers and commissioners of care or services

    • private, voluntary sector and other independent providers of care or services

    • companies that manufacture drugs, devices, equipment or adaptations, and commercial industries relevant to public health

    • organisations that fund or carry out research

    • Government departments and national statutory agencies.

  • Standard deviation

    A measure of the spread, scatter or variability of a set of measurements. Usually used with the mean (average) to describe numerical data.
  • Statistical power

    The ability of a study to demonstrate an association or causal relationship between 2 variables (if an association exists) means that the study is statistically significant. The statistical power of a study is primarily related to the number of people included. If too few people are included, any differences in the outcomes will not be statistically significant.
  • Structured interview

    A research technique in which the interviewer asks all study participants a list of pre-set questions.
  • Study checklist

    A set list of questions about the research methodology used to ensure a study is valid. A different checklist is used for each study type.
  • Study participant

    A person who takes part in an experiment or research study. Also known as a subject.
  • Study population

    People who are the subjects of a research study.
  • Study quality

    The extent to which a study has conformed to recognised good practice in the design and execution of its research methods.
  • Study type

    The way a study is designed. Case-control study, cohort study, non-randomised controlled trial, and randomised controlled trial are all examples of study types using different research methodologies.
  • Survey

    A study in which information is systematically collected from people (usually from a sample within a defined population).
  • Systematic

    Methodical, not random.
  • Systematic error

    Refers to the various errors or biases inherent in a study. See also bias.
  • Systematic review

    A review in which evidence from scientific studies has been identified, appraised and synthesised in a methodical way according to predetermined criteria. It may include a meta-analysis.
  • Systemic

    Involving the whole body.
  • Systemic disease

    A disease that affects the patient's whole body.
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