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Glossary and Instructions

Glossary and Instructions

Glossary and Instructions

Glossary for the Peer Support project Evidence and Gap Map

Glossary of key terms, categories (interventions, outcomes) and filters included in the Evidence and Gap Map. Please note that map category coding reflects information reported in the associated publication (and linked publications, where relevant). Where information was implied, but not stated, this was not coded onto the map.

Evidence and gap map (EGM) An Evidence and Gap Map (EGM) is an interactive tool, designed to provide visual presentations of the availability of rigorous evidence for a particular topic, theme, or policy area. EGMs commonly include systematic reviews and evaluations of impact on ‘what works’ in relation to a specified topic. Derived from a systematic and pre-defined search of available evidence, EGMs consist of a matrix of intervention categories (rows) and outcome domain (columns) placed into an intuitive graphical display. Navigating the map reveals areas for which there is strong, weak, or non-existent evidence available on the effect of interventions. In addition, filters may be available, for example for the type of study, or population characteristics. It is important to note that while EGMs show what evidence is available, they do not comment on what the evidence says (1,2).
Peer support

Whilst there are many different definitions of peer support, for the purposes of this EGM, we employed the one used within the Nesta and National Voices 2015 report:

“Peer support involves people drawing on shared personal experience to provide knowledge, social interaction, emotional assistance or practical help to each other, often in a way that is mutually beneficial”

In addition, we set the condition that there must be an identifiable peer support role, ongoing and formalised to include at least one of the following methods:

  • they have received training to fulfil the peer support role;
  • they receive ongoing support to fulfil the peer support role;
  • they are paid or have a contract to fulfil the peer support role.
Systematic review A study which collects and synthesises all of the research available on a topic in order to answer a specific question (34).  Systematic reviews seek to minimise bias by setting out their methods in advance, defining the types of study that will be included and methods that will be used to analyse the data for example.
Impact evaluation A study investigating the change in an outcome resulting from an intervention (5). Different study designs, such as RCTs, can be used to do this.
Randomised Controlled Trial An experimental study in which people are randomly allocated into different groups and each group receives a different intervention (6).
Economic evaluation A study which looks at the cost of delivering an intervention. This EGM includes economic evaluations, which compare the costs and outcomes of an intervention, as well as broader economic studies (7).
CategorySub-categoryExplanatory notes
Description of peer support initiative Case management, health service liaison Helping participant to make contact with available health and social care support.
  Education. coaching, mentoring Provision of information, education, training, mentoring and/or coaching.
  Practical support for health behaviours Practical help with health behaviours such as exercising, or learning to monitor blood glucose levels
  Psychological, emotional, wellbeing support Mental health support, mindfulness, wellbeing, and quality of life interventions.
  Self-care, self-management A focus on self-management, self-care and goal setting.

Social, community Social or community input. Aiming to help build relationships and/or support social interaction.
Not clearly defined N/A
Support structure for peers Trained N/A
  Paid or with contract N/A
  Receive ongoing support Supervision or additional training/mentoring provided for the peer.
  Not specified N/A
Struture of meetings One-to-one N/A
  In groups N/A
Method of contact In person N/A
  Telephone N/A
  Online N/A
  Not specified N/A
Who facilitates intervention Peers facilitate, not clear whether or how professionals involved Peers facilitate. Not clear whether there are clinicians also involved.
  Co-facilitated by peers and professionals Peers and professionals facilitate together.
  Led by peers, working with professionals Peers lead delivery of the intervention, working with professionals.
  Led by professionals, working with peers Professionals lead delivery of the intervention, working with peers.
  Not clearly defined N/A
Main focus of research Focus on peer support N/A
  Focus not on peer support alone Peer support is part of a complex intervention, or one of multiple intervention arms. Effects of peer support are identifiable.
Duration of intervention One-off or ad-hoc N/A
  Up to 3 months N/A
  Over 3, up to 6 months N/A
  Over 6, up to 12 months N/A
  Over 12 months N/A
  Not specified N/A
Location of intervention Own home N/A
  Medical setting N/A
  Community of social location N/A
  Not specified N/A


CategorySub-categoryExplanatory notes

Health related indicators
Outcomes measuring physical or mental health status

Physical health Indicator of physical health
Mental health Indicator of mental health
Skills for self-management, and practising behaviours linked to health and social outcomes

Self-management Learning and practicing skills to enable management of health and social needs on a day-to-day basis.

Health behaviours Health service utilisation (for example, appointment attendance, treatment engagement). Repeated behaviours that influence social and/or health outcomes.
Addiction recovery Outcomes related to addictive behaviours; such as smoking cessation, or changes in substance abuse.
Supporting self-regulation
Skills, understanding and attitudes potentially linked to self-regulation and management of health and social needs.

Self-efficacy Self-efficacy, empowerment. Self-advocacy. Self-esteem. Measures that quantify mental state and attitudes that are likely to translate into health behaviours.
Knowledge, understanding Knowledge, understanding, information held about own health condition, how to meet own social needs etc.
Wellbeing, social connectedness Wellbeing, quality of life Measures of quality of life, balance, wellbeing, positive lifestyle.
  Social support and relationships Perceived social connectedness, social support. Relationships.
Cost-effectiveness, service use Cost effectiveness Comparative analysis of two or more alternative interventions in terms of health, social and economic consequences.

Service use Measure of use of any health, social or other services.
Employment status Measure of employment status
Experience of peer support Experience of support Experience of receiving or providing peer support.
  Peer outcomes Outcomes for peer supporters.


CategorySub-categoryExplanatory notes
Study type Economic evaluation (EE) Effectiveness study looking at the economic impact of peer support interventions 
  Randomised controlled trial (RCT) Effectiveness study looking at the effectiveness of peer support interventions
  Systematic review (SR) A formalised (systematic) review of the available evidence on a specific question related to the effectiveness of peer support. May include RCTs, other effectiveness studies and/or other research 
Population characteristics Mental health difficulties/needs (acute) A short-term difficulty or need or a crisis related to chronic difficulties 
  Mental health difficulties/needs (chronic) Chronic needs or difficulties
  Physical health difficulties/needs (acute) A short-term difficulty or need or a crisis related to chronic difficulties 
  Physical health difficulties/needs (chronic) Chronic needs or difficulties 
  Addiction difficulties Can be with addition or in recovery. Includes alcohol and drugs 
  Parents, carers Parents or carers of people who have health or social care needs/difficulties
  Vulnerable (e.g. experienced trauma, homelessness, criminal justice contact) People identified as vulnerable, including people who have experienced homelessness, trauma, and/or contact with the criminal justice system. , those who have experienced trauma, in criminal justice system 

Population age
When range not given, reflects mean age, plus/minus standard deviation.

Includes young people 18-25 N/A
  Includes adults 26-64 N/A
  Includes older adults 65+ N/A
  Not clearly defined N/A

Study location/s by type of health system
Following stakeholder feedback, these categories were developed to indicate organisation of health systems.

United Kingdom (UK) Location of EEs and/or of studies included in

Europe (other than UK) Location of EEs and/or of studies included in

USA or Canada Location of EEs and/or of studies included in

Australia or New Zealand Location of EEs and/or of studies included in

Other/not specified Location of EEs and/or of studies included in

Assessment timeframe
Where possible this reflects time from intervention end. However, in some studies, reflects time since baseline.

An intervention end  N/A
  Up to 3 months  N/A
  Over 3, up to 6 months  N/A
       Over 6, up to 12 months  N/A
Over 12, up to 24 months  N/A
Over 24 months, up to 5 years  N/A
Over 5 years, up to 10 years  N/A
Lifetime Relevant for economic evaluations
Not specified N/A

 Quality appraisal: SR
overall confidence in quality of results (AMSTAR-2)

 High overall confidence Higher overall confidence
   Moderate overall confidence Higher overall confidence
    Low overall confidence Lower overall confidence 
 Critically low overall confidence Lower overall confidence 

 Quality appraisal: RCT
summary assessment of risk of bias (RoB)

 Low risk of bias Higher overall confidence
    Unclear risk of bias Lower overall confidence
 High risk of bias Lower overall confidence

 Quality appraisal: EE
overall quality assessment (CHEC-list)

 High Overall quality Higher overall confidence
   Medium overall quality Higher overall confidence
   Low overall quality Lower overall confidence
 Study year 2015  N/A
  2016  N/A
  2018  N/A
  2019  N/A
   2020  N/A
2021  N/A


Instructions for using the Peer Support project Evidence and Gap Map

The map will be displayed in your browser with a title and links to relevant documents. The mapping tool is not currently optimised for viewing on a mobile phone.

At the top of the browser, there is a tool bar with options: to view FiltersHide Headers, view the map in Fullscreen mode, read information About the map, and View Records. These elements are interactive and allow you experiment with how you view the information in the map. Header columns (OUTCOMES) and rows (INTERVENTIONS) and can be scrolled through to view all categories. You can expand or minimise categories for each column and row (to view sub-categories). To achieve this, use the arrows << >> (only visible when ‘Hide Headers’ option has not been chosen).

The rows in the map are intervention categories, while the columns indicate outcome categories. The cells displayed in the table contain a bubble whose size is proportional to the number of references reporting that outcome for that intervention/outcome. There are different bubbles to indicated overall quality of the included references. For the purposes of simplicity, all studies have been given an overall rating of HIGHER or LOWER confidence in research quality. Systematic reviews (SRs) have been assessed using the AMSTAR-2 tool; Randomised controlled trials (RCTs) using the Cochrane Collaboration risk of bias (ROB tool), and Economic Evaluations (EEs) using the CHEC-list. For more detailed information relating to the overall assessed quality or risk of bias of each included reference please use Filters (see below). The map has been prepared to be colour blind friendly. Blue colour bubbles indicate HIGHER confidence in research quality, while orange/yellow bubbles indicate LOWER confidence in research quality.

The map has four style versions available: bubble, heat, donut and mosaic. These are self-explanatory and can be accessed by clicking -> Filters (top left of map), and selecting your preferred Style. Clicking on a cell provides a list of studies corresponding to the intervention and outcome for that cell. Click on a study in the list to access publication details, relevant summaries and the URL to access the study itself.

The map includes a set of filters, including population categories and type of study. These allow the map to display evidence just for the selected filter. To use this tool, click -> Filters on the top-left of the map, then select the category of interest. Once your chosen filters have been selected, click -> Update.

To filter included records by specific keyword or topic, click ->View Records, enter a filter term, for example ‘Diabetes’ into the top toolbar. This will display records with this keyword. You can choose to filter by All, Title, Abstract or Author.

This evidence and gap map both displays recent available evidence on the effectiveness of peer support available evidence, and identifies ‘gaps’ or areas where no recent evidence has been identified. Where cells do not have any bubbles, this indicates that no evidence was identified for these fields. We have provided the abstracts of included references, summaries for systematic reviews, and a link to view the original source with access the full study where possible. It is important to note that while this EGM aims to show what evidence is available, is does not comment on what the evidence says.

First experiment with options for viewing the map. Try using the buttons on the top tool bar. ‘Filters’ will display filtering options; ‘Hide headers’ hides the title and provides more space for map navigation; ‘Fullscreen’ provides a larger view of the map; ‘About’ links to contextual information about the map; ‘View Records’ shows you all the references included in the map.


1. Use the View Records button (top right of screen) to identify how many studies are included in this map.
     a. Number?
2. Use the map to find out what recent research (RCT and SR) has been identified on peer support INTERVENTIONS including Education, coaching, mentoring with OUTCOMES that are health-related indicators of Physical health.
     a. How many in total?
     b. How many RCTs?
     c. How many SRs?
3. Use the Filters (top left of screen) to find out how many RCTs with a summary assessment of Low Risk of Bias are included in this map. [Hint, once you have filtered the map to show RCTs and Low Risk of Bias, click ‘View Records’ (top right) to see all records].
     a. How many RCTs?
4. Clear all Filters. Use the map to identify one area related to Peer Support INTERVENTIONS that includes Wellbeing support for which no OUTCOMES are reported in the current map. (Hint, look for empty squares).
     a. Name of ‘gap’?
5. You are only interested in the OUTCOMES of Peer Support INTERVENTIONS for populations with mental health difficulties. How can you Filter the map to make sure you look at a map of recent research with this population?
     a. How many records (use View Records tab) are now visible on the map?
6. You are only interested in recent Systematic Review evidence. How can you FILTER the map to make sure you look at a map of recent systematic reviews only?
     a. How many records (use View Records tab) are now visible on the map?