Indicator Methodology and Assurance Service


The Indicator Methodology and Assurance Service (IMAS) was established to develop and carry out the indicator assurance process. We also create and maintain the National Indicator Library - a library of quality assured indicators.

In response to the Francis Enquiry into Mid Staffordshire Hospital, we were asked by the Quality Improvement Committee (a sub-group of the National Quality Board) to establish an assurance process for handling work associated with the development of indicators. 

About indicators

An indicator is measure of something in health and social care, which can be used to track that thing over time, or to compare performance across organisations.

This information can be used to help managers and policy makers make better decisions.

What we do

We are a free service supporting anyone looking to develop health and social care indicators. We also review existing indicators by providing subject matter experts for review and feedback.

The service:

  • provides transparent records
  • ensures robust statistical methodologies are used in indicator development
  • assures that indicators answer the question being posed and are suitable for the intended audience
  • confirms that indicators support government policy
  • reduces indicator duplication
  • ensures correct information is provided so users can use an indicator
  • provides assurance to the users that the indicator is unlikely to change without due consideration
  • supports the development of indicators, with the view of inclusion in the National Indicator Library

How the process works

The assurance process includes the following stages:

  • independent peer review
  • assessment of indicator construction by the Methodology Review Group (a panel that meets fortnightly, consisting of epidemiologists, statisticians, indicator and data experts)

Findings from the assurance process are presented to the Indicator Governance Board, a cross-system body that provides strategic consideration of the indicator.

Alongside providing governance for the assurance process, the Indicator Governance Board fulfils the approval function required to accept indicators from across the health and social care systems as being suitable for inclusion in the National Indicator Library.

The assurance process is conducted using a single set of robust and consistently applied criteria. Regulations set out the statutory requirement for the library and allow any person or organisation to put forward indicators for inclusion.

Our boards consist of experts from across the health and social care system, who oversee the indicator assurance process, ensuring that all the correct stages have been followed.

The team support the assurance process through: 

  • providing an initial review (appraisal) of indicator specifications submitted for assurance
  • providing advice to applicants and developers using, or interested in using, the service
  • liaising with independent peer reviewers to enhance the quality of the assessment
  • acting as secretariat for both the Methodology Review Group and the Indicator Governance Board
  • administering the supporting systems to ensure a full audit trail of the decisions and recommendations made are captured
  • feeding back the results of assurance to applicants
  • publishing the results in the National Indicator Library


The European Standard Population (ESP) approach allows for comparability across the Health and Social Care sector and provides a universal standard for direct standardisation. This paper explains the recommended adoption of ESP in more detail:

Standardisation methods

Creating bespoke age bands - Public Health England

Indicator Governance Board - Chair's report 2017/18