Evidence Synthesis

What are evidence syntheses?

Evidence syntheses combine data from multiple sources, most commonly from existing research studies, to provide an overall summary of current knowledge. 

Evidence syntheses should be based on systematic processes to identify and collate relevant evidence that meets pre-specified eligibility criteria and to minimise the influence of bias. Combining individual study results and considering differences can reduce uncertainty and help make sense of conflicting study findings.

• Systematic reviews - aim to identify and formally evaluate all the studies addressing a clearly defined research question using methods that are set out in advance
• Rapid reviews - when an answer is needed quickly, researchers can use streamlined methods to produce a rapid review
• Scoping reviews or production of an evidence map – these can be carried out if we want to know what studies exist without looking in detail at their findings
• Statistical analysis  - evidence syntheses may include a statistical analysis that combines individual study results. This is called a meta-analysis or a network meta-analysis when three or more comparisons are being made within a single analysis
• Decision analytic modeling - is a means of estimating the costs, outcomes and cost-effectiveness of different interventions and programmes

Whatever kind of evidence synthesis is conducted, appropriate, rigorous and transparent methods must be used so that the conclusions can be trusted.

The Evidence Synthesis Programme is funded by the NIHR, with contributions from the Chief Scientist Office (CSO) in Scotland, Health and Care Research Wales, and the HSC R&D Division, Public Health Agency in Northern Ireland.

We support the production of evidence synthesis through two funding streams:

• Technology Assessment Review teams are funded by NIHR to provide NICE with independent research to inform their guidance committees
• Evidence Synthesis Groups (ESGs) are funded by NIHR to address knowledge gaps or to answer a specific need for the Programme’s healthcare, public health and social care stakeholders/audiences

We also fund the infrastructure for the Cochrane UK centre which provides training and support to Cochrane entities and contributors to the Cochrane Collaboration in the UK, Scotland and Ireland.

Evidence Synthesis Groups (ESGs)

Nine Evidence Synthesis Groups (ESGs) have been funded to undertake a range of evidence syntheses reviews for the Evidence Synthesis Programme. The aim of the ESGs is to address knowledge gaps or to answer a specific need for the Programme’s healthcare, public health and social care stakeholders/audiences. These will be areas of importance to policy makers and will have a direct impact on decision-making, patient and client care, reducing inequalities and identifying future research needs. The teams are expected to deliver approximately three to five evidence syntheses a year depending on the size and complexity of the reviews and each team has been funded for five years.

The nine commissioned ESGs are:

• Bristol Evidence Synthesis Group, University of Bristol
• Complex Reviews Support Unit (CRSU) Evidence Synthesis Group, University of Glasgow 
• Evidence Synthesis group for NIHR Sheffield (EnSygN), University of Sheffield
• Isca Evidence, University of Exeter
• London Alliance for the Coproduction of Evidence Synthesis (LACES), University College London
• NIHR Evidence Synthesis Scotland Initiative (NESSIE), University of Edinburgh
• Aberdeen Belfast Evidence Collaboration (ABEC), University of Aberdeen
• West Midlands - Evidence Synthesis Group (WM-ESG), University of Warwick
• York Evidence Synthesis (YES) Group, University of York

Our people

To assess the applications the Evidence Synthesis Programme receives, a variety of stakeholders are involved. This is to ensure that application selection is carried out in a way that embraces the latest expertise, knowledge and opinion.

Find out more about becoming a reviewer or a Committee member.

Our Director

Our Director is Professor Lesley Stewart

Evidence Synthesis Programme Prioritisation and Advisory Group (ESPPAG)

The role of the ESPPAG is to support the ESP Director in an advisory capacity on matters relating to evidence synthesis at national, international and regional levels and on the strategic direction of the Programme. The ESPPAG also reviews and prioritises topics that will be allocated to the Evidence Synthesis Groups. The ESPPAG seeks to ensure all programmes of work are of scientific quality, relevant to the NHS, and show value for money through the management of annual reporting and monitoring.

Reviewers

Members of the ESPPAG and Funding Committees are required to declare any interests which conflict, or may be considered to conflict, with Evidence Synthesis Programme business, or may be perceived as influencing decisions made in the course of their work with the programme. All members are asked to complete the Register of Interest form, which is intended to capture long term predictable interests that could be perceived to lead to conflicts of interest. These and other interests are judged on a case by case basis at individual meetings.

Technology Assessment Reviews

The Evidence Synthesis Programme manages the contracts for the 11 NIHR Technology Assessment Reviews (TAR) research teams. The teams respond to the urgent needs of the National Institute for Health and Care Excellence (NICE), and other policy makers. The Evidence Synthesis Programme works with NICE and the teams to manage the allocation of the topics on their call off contract. Find out more about our work with NICE.

NICE’s role is to improve the outcomes for people using the NHS, and other public health and social care services. One of the ways it does this is by producing evidence-based guidance. NICE guidance contains systematically-developed recommendations based on the best evidence.

The TAR research teams provide NICE with the independent research it needs to inform its guidance committees, through a variety of different types of specialised report, suited to the decision-making process.

Working with other policy makers

TAR reviews can also be commissioned to provide evidence for other policy customers. The TAR research teams can respond quickly to requests, providing an important resource for policy makers, such as the National Screening Committee, Chief Medical Officer and NHS England.  TAR reports are independent, reliable and rigorous evidence assessments; they usually comprise a systematic review, cost-effectiveness and economic modelling.

The 11 TAR teams are:

• Aberdeen HTA Group, University of Aberdeen
• BMJ Technology Assessment Group (BMJ-TAG)
• Bristol Technology Assessment Group, University of Bristol
• Centre for Reviews and Dissemination/Centre for Health Economics, University of York
• Kleijnen Systematic Reviews Ltd
• Liverpool Reviews and Implementation Group, University of Liverpool
• Newcastle NIHR TAR Team, Newcastle University
• PenTAG, Evidence Synthesis & Modelling for Health Improvement (ESMI), University of Exeter
• School of Health and Related Research, University of Sheffield
• Southampton Health Technology Assessments Centre, University of Southampton
• Warwick Evidence, University of Warwick

The team can be contacted at esptar@nihr.ac.uk

Contact us

For help with applications or support with Evidence Synthesis Programme funding, contact:

Email:  espinfo@nihr.ac.uk
Telephone: 023 80595542