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Validation errors and warnings are only relevant to Cochrane authors submitting reviews to Cochrane. RevMan subscribers can disregard validation errors and warnings.

Validation report

The validation report shows you discrepancies between your review and Cochrane standards for a review.

These can be defined as Errors or Warnings. Errors MUST be addressed before submission, as you will not be able to submit your Cochrane Review to Editorial Manager with errors present. All warnings should also be checked, with reference to editorial policy as required.

You can see validation errors and warnings relevant to your review on the Dashboard. Expand or collapse the Validation menu to view further details.

In Intervention and flexible reviews, validation errors and warnings are also visible in the right-hand Context pane. Use the links to navigate to the next issue you need to address.

Validation rules

Validation errors and warnings are generated dynamically depending on the specific content of the review, and so the below list is not exhaustive - rules not in this list may still apply.

	Type	Section	Validation rule	Review stage	Description
1	Error	Abstract	Abstract cannot exceed 1000 words.	R	The abstract cannot be longer than 1000 words (word count: [count])
2	Error	Figures	Figure should be linked from text.	P + R	Figure is not linked from the text.
3	Error	Additional table	Table should be linked from the text.	P + R	Table is not linked from the text.
4	Error	Analysis	An active choice of labels for graph axes is required.	R	The default graph label 'Favours [experimental]' must be changed.
5	Error	Dates	Date of Search cannot be empty.	R	Date of search is empty.
6	Error	Plain language summary	Summary cannot exceed 850 words.	R	The plain language summary cannot be longer than 850 words (word count: [count])
7	Error	Published notes	Cannot be empty for withdrawn reviews.	P+R	Published notes do not contain the reason for withdrawal. Provide a brief explanation of why the review was retracted. See Withdrawing articles published in the CDSR.
8	Error	Summary title	Default text '[Summary title]' should be modified.	R	The plain language summary title is empty.
9	Error	Analysis	Synthesis PICO not completed.	P+R	Synthesis PICO is not completed. The review cannot be checked in until outcome and interventions have been specified.
10	Error	What's new	Section cannot be empty unless protocol or review is new. See also What’s new events.	P+R	What's new is empty.
12	Error	Differences between the protocol and review	Field cannot be empty.	R	Differences between protocol and review is empty.
13	Error	Main text sections	Mandatory text sections (depending on stage) cannot be empty. See full list of validation of text sections below.	P+R	[Section] is empty.
14	Error	Event	Only events relevant to the current stage are allowed.	P+R	Event is not allowed at [Protocol/Full review] stage.
15	Error	Event	Description cannot be empty.	P + R	Description is empty.
16	Error	Dates	Date of Search cannot be in the future.	R	Date of Search is in the future.
17	Error	Dichotomous study data	Events <= Total	R	The number of events cannot be larger than the number of totals.
18	Error	What's new	Section cannot include more than one New citation event. See also What’s new events.	P + R	More than one declaration event ('New citation' or 'No longer being updated').
19	Error	Event	Withdrawn reviews only support Amended events.	R	Withdrawn reviews only support Amended events.
20	Error	What's new	If an Updated event is present, there must be a New citation event. See also What’s new events.	R	An updated event is present without declaring a new citation.
21	Error	Dates	Assessed as Up-to-date cannot be empty.	R	Assessed as Up-to-date is empty.
22	Error	Included study, Excluded study	Study should have at least one reference.	R	If a Study ID is inserted in the References to studies section, a reference must be added
23	Error	Included study	All included studies must be cited in the main article.	R	Included study not cited in the main article, including additional tables.
24	Error	Dates	Assessed as Up-to-date cannot be in the future.	R	Assessed as Up-to-date is in the future.
34	Error	Reference	All fields should not be empty at the same time.	P+R	Reference is empty.
35	Error	Reference	Required fields should not be empty.	P+R	[Field name] is empty.
36	Error	What's new	If a New citation event is present, there should usually also be an Updated event. See also What’s new events.	R	A new citation is declared without the review being updated
25	Warning	Studies	All fields in study characteristics should not be empty at the same time.	R	Study characteristics are missing.
26	Warning	Additional reference	Reference should be linked from the text.	P+R	Reference is not linked from the text.
27	Warning	Figures	The recommended Number of figures has been exceeded.	P+R	The recommended maximum number of figures (6) has been exceeded - please remove [n].
28	Warning	Figures	Other figures must contain an image file.	P+R	No file uploaded for figure [n]
29	Warning	Figures	Other figures should be more than 500 pixels wide	P+R	Other figures should be more than 500 pixels wide
37	Warning	Cochrane review reference, Cochrane protocol reference	The DOI identifier should be specified correct.	P + R	DOI should be corrected according to these examples: 10.1002/14651858.CD123456 or 10.1002/14651858.CD123456.pub2
38	Warning	Cochrane review reference, Cochrane protocol reference	SO field should be 'Cochrane Database of Systematic Reviews'.	P + R	Journal/Book/Source should be Cochrane Database of Systematic Reviews.
39	Warning	Cochrane review reference, Cochrane protocol reference	Should have DOI identifier.	P + R	DOI is missing.
40	Warning	Comparison	Should not have empty analyses.	R	One or more analyses have no associated study data.
41	Warning	Inverse variance analyses or subgroup	Option to enter number of participants has been selected, but no data have been entered for any studies.	R	The option to enter number of participants has been selected, but no data have been entered.
42	Warning	Other data type analyses	No column heading should be empty.	R	One of the column headings is empty.
43	Warning	What's new	If an Updated event is present, the Date of search should be less than 12 months old. See also What’s new events.	R	The What’s new Event 'Updated' is selected but the Date of search is more than 12 months ago.
44	Warning	Sources of support	Section could not be empty.	P+R	No sources of support listed.

R= Full Review stage
P= Protocol stage

Validation of empty text sections

The intervention review template aids authors in what to report where to ensure compliance with PRISMA and will improve consistency across Cochrane reviews for reader. The following table shows validation of empty text sections in both the focused and the long review formats. It also shows how review headings have changed, indicating where text has moved to if a section has been removed in switching to the focused review format.

High level headings that do not have a corresponding text field and therefore do not need to be validated are highlighted in light blue.

Flexible reviews

In the 'Text' section of flexible reviews only the Heading 1 (H1) level is displayed. Sub-headings can be created by authors from the formatting toolbar. See Add or adjust subheadings.

Level 1 heading	H1
Level 2 heading	H2
Level 3 heading	H3
Level 4 heading	H4

Focused review format	Focused format validation Error = section cannot be empty Warning or No validation = optional but check template for reporting guidance	Long review format	Long format validation Error = section cannot be empty Warning or No validation = optional but check template for reporting guidance
(H1) Title		(H1) Title
(H1) Abstract		(H1) Abstract
(H2) Rationale	Error	(H2) Background	Error
(H2) Objectives	Error	(H2) Objectives	Error
(H2) Search methods	Error	(H2) Search methods	Error
(H2) Eligibility criteria	Error	(H2) Selection criteria	Error
(H2) Outcomes	Error
(H2) Risk of bias	Error
(H2) Synthesis methods	Error	(H2) Data collection and analysis	Error
(H2) Included studies	Error
(H2) Synthesis of results	Error	(H2) Main results	Error
(H2) Authors' conclusions	Error	(H2) Authors' conclusions	Error
(H2) Funding (all review types)	Error
(H2) Registration (all review types)	Error
(H1) Plain language summary	Error	(H1) Plain language summary	Error
(H1) Plain language summary title	Error	(H1) Plain language summary title	No validation
Key messages	No validation	Key messages	No validation
Tailored heading: e.g. What is epilepsy?	No validation	Tailored heading: e.g. What is epilepsy?	No validation
Optional tailored heading: e.g. How is epilepsy treated?	No validation	Optional tailored heading: e.g. How is epilepsy treated?	No validation
What did we want to find out?	No validation	What did we want to find out?	No validation
What did we do?	No validation	What did we do?	No validation
What did we find?	No validation	What did we find?	No validation
Main results	No validation	Optional heading: Main results	No validation
What are the limitations of the evidence?	No validation	What are the limitations of the evidence?	No validation
How up to date is this evidence?	No validation	How up to date is this evidence?	No validation
(H1) Summary of findings	No validation	(H1) Summary of findings	No validation
Summary of findings tables		Summary of findings tables	No validation
(H1) Background	No validation	(H1) Background	No validation
(H2) Description of the condition	Warning	(H2) Description of the condition	Warning
(H2) Description of the intervention and how it might work	Warning	(H2) Description of the intervention	Warning
		(H2) How the intervention might work (text moved to ‘Description of the intervention and how it might work’ section in focused format)	Warning
(H2) Why it is important to do this review	Error	(H2) Why it is important to do this review	Warning
(H1) Objectives	No validation	(H1) Objectives	Error
(H1) Methods	No validation	(H1) Methods
(H2) Criteria for considering studies for this review	Error	(H2) Criteria for considering studies for this review	No validation
(H3) Types of studies	Error	(H3) Types of studies	Error
(H3) Types of participants	Error	(H3) Types of participants	Error
(H3) Types of interventions	Error	(H3) Types of interventions	Error
(H2) Outcome measures	Error	(H3) Types of outcome measures	Warning
(H3) Critical outcomes	Error	(H4) Primary outcomes	Warning
(H3) Important outcomes	Error	(H4) Secondary outcomes	Warning
(H2) Search methods for identification of studies	Error	(H2) Search methods for identification of studies	No validation
(H3) Electronic searches	Error	(H3) Electronic searches	Error
(H3) Searching other resources	Error	(H3) Searching other resources	Error
(H2) Data collection and analysis	No validation	(H2) Data collection and analysis
(H3) Selection of studies	Error	(H3) Selection of studies	Error
(H3) Data extraction and management	Error	(H3) Data extraction and management	Error
(H3) Risk of bias assessment in included studies	Error	(H3) Assessment of risk of bias in included studies	Error
(H3) Measures of treatment effect	Error	(H3) Measures of treatment effect	Error
(H3) Unit of analysis issues	Error	(H3) Unit of analysis issues	Error
(H3) Dealing with missing data	Error	(H3) Dealing with missing data	Error
		(H3) Assessment of heterogeneity (text moved to ‘Synthesis methods’ section in focused format)	Error
(H3) Reporting bias assessment	Error	(H3) Assessment of reporting biases	Error
(H3) Synthesis methods	Error	(H3) Data synthesis	Error
(H3) Investigation of heterogeneity and subgroup analysis	Error	(H3) Subgroup analysis and investigation of heterogeneity	Error
(H4) Equity-related assessment	Error
(H3) Sensitivity analysis	Error	(H3) Sensitivity analysis	Error
(H3) Certainty of the evidence assessment (L3)	Error	(H3) Summary of findings and assessment of the certainty of the evidence	Error
(H2) Consumer involvement	Error
(H1) Results	No validation	(H1) Results
(H2) Description of studies	No validation	(H2) Description of studies	Warning
(H3) Results of the search	Error	(H3) Results of the search	Error
(H3) Included studies	Error	(H3) Included studies	Error
(H3) Excluded studies	Error	(H3) Excluded studies	Error
(H2) Risk of bias in included studies	No validation	(H2) Risk of bias in included studies	Error
		(H3) Allocation (selection bias)	Error if 'Risk of bias in included studies' section is empty
		(H3) Blinding (performance bias and detection bias)	Error if 'Risk of bias in included studies' section is empty
		(H3) Incomplete outcome data (attrition bias)	Error if 'Risk of bias in included studies' section is empty
		(H3) Selective reporting (reporting bias)	Error if 'Risk of bias in included studies' section is empty
		(H3) Other potential sources of bias	Error if 'Risk of bias in included studies' section is empty
(H2) Synthesis of results	Error	(H2) Effects of interventions	Error
(H3) Equity assessment	No validation
(H3) Reporting biases	No validation
(H1) Discussion	No validation	(H1) Discussion
(H2) Summary of main results	Error	(H2) Summary of main results	Error
(H2) Limitations of the evidence included in the review	Error	(H2) Overall completeness and applicability of evidence	Error
		(H2) Quality of the evidence (text moved to ‘Limitations of the evidence included in the review’ section in focused format)	Warning
(H2) Limitations of the review processes	Error	(H2) Potential biases in the review process	Error
(H2) Agreements and disagreements with other studies or reviews	Error	(H2) Agreements and disagreements with other studies or reviews	Error
(H1) Authors' conclusions	No validation	(H1) Authors' conclusions
(H2) Implications for practice	Error	(H2) Implications for practice	Error
(H3) Equity-related implications for practice	No validation
(H2) Implications for research	Error	(H2) Implications for research	Error
(H3) Equity-related implications for research	No validation
(H1) Supplementary materials (all review types)	No validation	(H1) Appendices	No validation
All supplementary materials listed
(H1) Additional information	No validation	(H1) Additional information	No validation
(H2) Acknowledgements	Error	(H2) Acknowledgements	Error
(H2) Contributions of authors	Error	(H2) Contributions of authors	Error
(H2) Declarations of interest	Error	(H2) Declarations of interest	No validation
(H2) Sources of support	Error	(H2) Sources of support	No validation
		(H2) Differences between protocol and review (text moved to ‘Methods’ section in focused format)	Error
(H2) Registration and protocol (all review types)	Error
(H2) Data, code and other materials (all review types)	Error
(H2) Published notes	No validation	(H2) Published notes	No validation
(H2) What's new	Error	(H2) What's new	No validation
(H2) History	No validation	(H2) History	No validation
(H1) References		(H1) References
		(H2) References to studies included in this review	No validation
		(H2) References to studies excluded from this review	No validation
		(H2) References to studies awaiting assessment	No validation
		(H2) References to ongoing studies	No validation
		(H2) Additional references	No validation
		(H2) References to other published versions of this review	No validation
(H1) Figures	No validation	(H1) Figures	No validation
(H1) Tables (all review types)	No validation	(H1) Additional tables	No validation