The information below details the section headings that you should include in your manuscript and what information should be within each section.
Please note that your manuscript must include a 'Declarations' section including all of the subheadings (please see below for more information).
This should list the title of the article. The title should include the review question, for example: What is the effectiveness of intervention A in producing change in subject B? What is the impact of factor X on subject Y?
The title should also indicate that it is a systematic review, for example:
- What is the effectiveness of intervention A in producing change in subject B? A systematic review.
- What is the impact of factor X on subject Y? A systematic review.
The full names, institutional addresses, and email addresses for all authors must be included on the title page. The corresponding author should also be indicated.
The Abstract of the manuscript should not exceed 500 words and must be structured into the following separate sections:
Background, the context and purpose of the review, including the review question;
Methods, how the review was performed including brief overview of all methodological steps and statistical tests used;
Review findings, the main findings, including results of search and assessment of evidence base;
Conclusions, brief summary and potential implications for policy/management and research.
Three to ten keywords representing the main content of the article should be given. Please avoid repeating words that are already in the title.
The Background section should be written in a way that is accessible to researchers without specialist knowledge in that area and must clearly state - and, if helpful, illustrate - the background to the review and its aims. Reports should indicate why this study was necessary and what it aimed to contribute to the field. A theory of change and/or conceptual model should be presented that links the intervention or exposure to the outcome. The role of stakeholders in the formulation of the question should be described and explained. The section should end with a brief statement of what is being reported in the article. A clear reference should be made to the protocol and any differences between what was planned and what was conducted.
Objective of the Review
This section should describe the primary question and secondary questions when applicable. The primary question is the main question of the review. The secondary questions are usually linked to possible subgroup analyses. This section may also present definitions of the primary question components (e.g. the subject, intervention and outcome measure) but see ‘study eligibility criteria’ below.
This section should include the design and conduct of the review. This section may be repetitive of the protocol but should be given in full with reference to any deviations from the protocol. Direct citation of the protocol should be made here and deviations from the protocol explained in the appropriate sections. A clear description of all review stages should typically follow the format;
Search for articles
Here the searches are described in sufficient detail so as to be repeatable. Direct citation of the protocol should be made here and deviations from the protocol explained in the appropriate sections. The following subsections are a guide to the detail required on what was searched and how the search was conducted.
- Search terms and languages. How were decision made on the keywords and languages to be used?
- Search strings for each of the search conducted provided in a supplementary file (search strings refer to combinations of terms using Boolean characters). Trial development of search strings may be included as an Additional File.
- Estimating the comprehensiveness of the search. How did you test how your search performs in terms of identifying all relevant studies?
- Publication Databases and services to be searched (including details of institutional subscriptions (or date ranges subscribed for each database searched), search options (e.g. ‘topic words’ or ‘full text’ search facility))
- Internet searches to be conducted. Give details of how you coped with limitations to use of search strings and limiting number of hits considered.
- Specialist searches - Searches for grey literature: stakeholder contacts, searches of organisational websites. Describe use of specific search terms or strings, filtering or limitations.
- Supplementary searches such as Bibliographical searches, hand searches and literature provided directly by experts or stakeholders
Article screening and study eligibility criteria
Confirm or state deviations in the screening process and test(s) for consistency of decision regarding inclusion/exclusion, at title, abstract, full-text level. Describe the role of systematic reviewers (who have also authored articles considered within the review) in decisions regarding inclusion or study validity assessment of their own work.
Here confirm (or state deviations) definitions followed to include eligible articles based on the following aspects, so that this stage is transparent and replicable by any external reader.
- Eligible population(s) or subject(s)
- Eligible intervention(s) or exposure(s)
- Eligible comparator(s) (if appropriate)
- Eligible outcomes
- Eligible types of study design
Study validity assessment
Describe here the methods you used to critically appraise and assess validity of included studies. Consideration should be given to ensuring that important aspects of study validity which would influence the reliability of the evidence were taken into account, such as internal validity (risk of bias or confounding) and external validity (generalisability of a study’s results to the current Systematic Review question). Report any checklists used and how they deviated from the protocol. Describe how the information from this assessment was used in synthesis and how repeatability of critical appraisal of study validity was tested.
Data coding and extraction strategy
State what categories of data were extracted. Describe here how you collected and recorded outcome data and associated meta-data from included studies. Report any checklists used and how they deviated from the protocol. State how the data extraction was conducted and how you tested for repeatability. Describe any process for obtaining and confirming missing or unclear information or data from authors.
Potential effect modifiers/reasons for heterogeneity
Confirm or update the list of those effect modifiers and reasons for heterogeneity considered in the review and details of how the list was compiled (including consultation of external experts).
Data synthesis and presentation
Describe here the methods you used to synthesise the collected qualitative and/or quantitative data and any subsequent manipulation of the data set (e.g. sub-group analyses). Synthesis methodology should be justified and fully explained. Narrative synthesis methodology should be described. If all studies were not selected for synthesis explain criteria for selection (e.g. incomplete or missing information).
If data are appropriate for quantitative synthesis, methods for calculating effect sizes, handling complex data, statistical methods for combining data from individual studies, and any exploration of heterogeneity and publication bias should be described.
Results of each stage of the review (e.g. search statistics, eligibility, study validity assessment, data extraction, reasons for variability in the results found and potential confounding factors, summary statistics) should be clearly reported. A flow diagram reporting the inclusion/exclusion process should be presented. A narrative synthesis of included studies (usually in tabular form) should always be provided (can be as additional material when appropriate). Results of qualitative, quantitative or mix-method syntheses should be fully reported with appropriate figures, tables and statistical values. Subsections should follow the format:
Review descriptive statistics, systematic map (sub-headings as applicable)
Report here the date(s) of the search you conducted, the number of articles found in the search and included at each inclusion level, along with results of consistency checking at all stages (screening, data extraction, critical appraisal) must be provided. Descriptive statistics should be provided on any relevant information on the distribution of the articles found (e.g. geographical, temporal, institutional) in order to assess potential gaps or bias in the evidence. Some mapping of the evidence could be provided here if this was planned as an intermediate step. If any studies are excluded due to low validity, provide the number of studies excluded from further synthesis during study validity assessment. For full transparency, additional files are expected here including:
- Tables of how articles (all and included only) were found (i.e. through which search database etc)
- A list of studies excluded at full text together with reasons for exclusion (this may be derived from your screening checklist as described in your protocol).
Narrative synthesis including validity assessment
For each included study provide a summary of validity assessment as a table. Data extracted, including metadata and findings along with other key information such as location and reporting of effect modifiers should be presented as a table or additional file (this also serves as a list of all included studies). A narrative synthesis will normally be provided as text and/or in tabular form, either in the main body of the paper or as an appendix. If any studies are excluded due to low validity, provide the number of studies excluded from further synthesis during critical appraisal.
Report here results of qualitative, quantitative or mix-method synthesis of extracted data. If meta-analyses have been conducted present full details, including effect sizes and related statistics (e.g. tests for heterogeneity) and, if possible, results of tests for potential biases. Data should have been utilised to their full potential to answer the question.
If a meta-analysis has been conducted please present an evaluation of the level of variation in effect of the intervention/exposure and possible reasons for these variations including the possible effect modifiers and impact of heterogeneity in the study variables such as experimental design.
A detailed discussion of the limitation of the review including limitations due to the search strategy (limitations of the review), as well as limitations due to underling bias within the studies found such as baseline bias and confounding variables (limitations of the evidence base). Gaps in the information provided by the studies should also be highlighted.
This section should be divided into:
Implication for Policy/Management
This summarises the state of the evidence base and the extent to which this informs decision making in relation to the review question and any measure of the uncertainty surrounding the outcome. The intention is to inform and any form of advocacy should be excluded.
Implication for Research
This section summarises the shortcomings of the current evidence base in terms of knowledge gaps and the need for primary research. In this section some advocacy for research is permissible provided it is clearly justified by the review outcome. This should take the form of recommendations for future study designs that would improve the evidence base.