Indicator Methodology and Assurance Service


The Indicator Methodology and Assurance Service (IMAS) is a dedicated system-wide resource hosted by NHS Digital, conducting assessments against set transparent criteria. IMAS works collaboratively with colleagues to develop quality indicators and to support applicants through the quality assurance process.

Assuring the quality of indicator methodologies has been driven by recommendations for mechanisms to bring transparency to health information. 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

Each indicator is an evidence-based measure. Its importance is taken from its linkage to whether government policy is carried out, a critical business question or a NICE quality standard and set, or domain.

About IMAS

We were established by NHS Digital to develop and carry out the assurance process following the introduction of the statutory regulations underpinning the Health and Social Care Act 2012.

Alongside supporting governance for the assurance process, we exist to ensure NHS Digital's statutory requirements to create and maintain an indicator library of quality assured indicator specifications can be met.

As well as setting out the requirement to build and populate the library regulations, the Act also describes the process by which indicators can be assessed as suitable for inclusion in the library. 

What we do

IMAS is a free service supporting anyone looking to develop health and social care indicators, or to review existing indicators by providing subject matter experts to offer comprehensive reviews 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 - this decreases the amount of work needed and minimises confusion amongst potential users
  • ensures sufficient information is provided to potential users to implement the indicator appropriately
  • provides assurance to the users that the indicator is not likely to change over time without due consideration
  • supports the development of indicators with the view of inclusion in a National Library of Quality Assured Indicators

How the process works

The assurance process includes a number of stages, which are: independent peer review; assessment of indicator construction by the Methodology Review Group (a panel that meets on a fortnightly basis consisting of epidemiologists, statisticians, indicator and data experts). Findings from the assurance process are presented to the Indicator Governance Board (IGB), a cross system body that provides strategic consideration of the indicator. 

Alongside providing governance for the assurance process, IGB fulfils the approval function required to accept indicators from across the health and social care systems as being suitable for inclusion in the National Library of Quality Assured Indicators. 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 make clear that any person or organisation can put forward indicators for inclusion in the library. 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 IMAS team support the assurance process through: 

  • providing an initial review (appraisal) of indicator specifications submitted for assurance in support of the applicant
  • 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 MRG and IGB
  • 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 Library of Quality Assured Indicators