In association with

  • Bristol, North Somerset and South Gloucestershire Integrated Care Board
  • West of England Academic Health Science NetworkWest
  • National Institute for Health Research


Relative risk reduction (RRR)

The percentage reduction in events in the treated group event rate (EER) compared to the control group event rate (CER): RRR = (CER-EER) / CER.


The extent to which the method used to collect data about a variable, produces consistent results from the same subjects, reproducible at different times when there is no evidence of change in the subjects


The systematic collection, analysis and interpretation of data to answer a particular question in order to generate new knowledge by establishing a truth.

Research evidence

Studies can be categorised according to the questions they seek to answer, and the evidence for evidence-based commissioning could include the following study types:
Descriptive: to identify the qualities and distributions of variables
Taxonomic: to compare and classify variables into related groups or categories.


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.


The way participants are selected for inclusion in a study.

Sampling frame

A list or register of names used to recruit participants to a study.


Social Care Institute for Excellence is an independent charity working with adults, families and social work services across the UK, including health care and housing. They gather and analyse knowledge about what works and translates it into practical resources, learning materials and services including training and consultancy.


The proportion of people with disease who have a positive test.


The proportion of people free of a disease who have a negative test.


Social Science Research Network (SSRN) is devoted to the rapid worldwide dissemination of social science research and is composed of a number of specialized research networks in each of the social sciences.

Standard deviation

A measure used to summarise numerical data and describe how ‘spread-out’ a set of measures (or values) are from the average. For example, the average height of a group of schoolchildren can be calculated using the total of all their heights added together and then divided by the number of schoolchildren in the group. Standard deviation measures the ‘spread’ of those heights. So, in the example it tells you whether all those in the group were about the same height, or whether some were very tall and some were short.