What is the STROBE checklist?

STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) is a 22-item checklist of what to report in a cohort, case-control or cross-sectional study. Eighteen items are the same for all three designs; items 6, 12, 14 and 15 have wording specific to each design. It was published in 2007 and is the reporting guideline most journals ask for with observational research.

Which STROBE checklist should I use: cohort, case-control, cross-sectional or combined?

Use the checklist for your design. The STROBE Initiative publishes separate versions for cohort, case-control and cross-sectional studies and a combined version with all three. Choose your design above and the tool shows only the wording that applies, for example how loss to follow-up was handled for a cohort study or how matching was handled for a case-control study.

How do I fill in the STROBE checklist?

For each item, find where your manuscript reports it and write the location, such as “Methods, Statistical analysis, p. 7”. If an item does not apply, for example matching in an unmatched study, mark it not applicable and say why. Upload the completed checklist as a supplementary file, and update the page numbers after revisions.

Is the STROBE checklist mandatory?

Many medical and public health journals require a completed STROBE checklist for observational studies, and others recommend it. Check the target journal’s instructions for authors. Even when it is optional, editors and reviewers often use the items to judge whether the methods and results are reported fully.

Is STROBE a quality or risk-of-bias assessment tool?

No. STROBE says what to report, not how good a study is. A well-reported study can still have serious bias. For appraising observational studies in a systematic review, use a risk-of-bias tool such as ROBINS-I or the Newcastle-Ottawa Scale instead.

Does STROBE apply to retrospective studies and registry data?

Yes. Retrospective cohort studies and chart reviews are observational studies, so STROBE applies. If the study uses routinely collected health data, such as electronic health records, claims or registries, also use the RECORD extension, which adds items on data sources, linkage and code lists.

Which checklist should I use instead of STROBE?

Randomised trials use CONSORT, systematic reviews use PRISMA, diagnostic accuracy studies use STARD, prediction model studies use TRIPOD, case reports use CARE and qualitative studies use SRQR or COREQ. Mendelian randomisation studies use STROBE-MR.

Should I write page numbers or section names?

Follow the journal’s instructions. Page numbers change when a manuscript is reformatted, so many authors give the section and paragraph, for example “Methods, Participants, para 2”, or both. Whatever you choose, make sure the location still matches the final submitted file.

Are my answers stored anywhere?

No. The checklist runs in your browser and nothing is sent to a server. Your answers are kept in this browser’s local storage so they are still there when you come back; use “Clear answers” to remove them.

STROBE Checklist for Observational Studies

Choose your study design, mark each of the 22 STROBE items as reported or not applicable, and note where it appears in your manuscript. Then download the completed checklist as a Word file to upload with your submission. Your answers are saved in this browser only.

Manuscript title (optional)

Study design

Cohort studyCase-control studyCross-sectional studyAll three

Items 6, 12(d), 14(c) and 15 change with the design. Items that do not apply to it are hidden.

0 of 34 items done

0 reported · 0 not applicable · 34 open

Show open items only

Title and abstract

1(a)
Title and abstract
Indicate the study’s design with a commonly used term in the title or the abstract
1(b)
Title and abstract
Provide in the abstract an informative and balanced summary of what was done and what was found

Introduction

2
Background/rationale
Explain the scientific background and rationale for the investigation being reported
3
Objectives
State specific objectives, including any prespecified hypotheses

Methods

4
Study design
Present key elements of study design early in the paper
5
Setting
Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection
6(a)
Participants
Cohort study—Give the eligibility criteria, and the sources and methods of selection of participants. Describe methods of follow-up Case-control study—Give the eligibility criteria, and the sources and methods of case ascertainment and control selection. Give the rationale for the choice of cases and controls Cross-sectional study—Give the eligibility criteria, and the sources and methods of selection of participants
6(b)
Participants
Cohort study—For matched studies, give matching criteria and number of exposed and unexposed Case-control study—For matched studies, give matching criteria and the number of controls per case
7
Variables
Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable
8*
Data sources/measurement
For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group
9
Bias
Describe any efforts to address potential sources of bias
10
Study size
Explain how the study size was arrived at
11
Quantitative variables
Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen and why
12(a)
Statistical methods
Describe all statistical methods, including those used to control for confounding
12(b)
Statistical methods
Describe any methods used to examine subgroups and interactions
12(c)
Statistical methods
Explain how missing data were addressed
12(d)
Statistical methods
Cohort study—If applicable, explain how loss to follow-up was addressed Case-control study—If applicable, explain how matching of cases and controls was addressed Cross-sectional study—If applicable, describe analytical methods taking account of sampling strategy
12(e)
Statistical methods
Describe any sensitivity analyses

Results

13(a)*
Participants
Report numbers of individuals at each stage of study—eg numbers potentially eligible, examined for eligibility, confirmed eligible, included in the study, completing follow-up, and analysed
13(b)*
Participants
Give reasons for non-participation at each stage
13(c)*
Participants
Consider use of a flow diagram
14(a)*
Descriptive data
Give characteristics of study participants (eg demographic, clinical, social) and information on exposures and potential confounders
14(b)*
Descriptive data
Indicate number of participants with missing data for each variable of interest
14(c)*
Descriptive data
Cohort study—Summarise follow-up time (eg, average and total amount)
15*
Outcome data
Cohort study—Report numbers of outcome events or summary measures over time Case-control study—Report numbers in each exposure category, or summary measures of exposure Cross-sectional study—Report numbers of outcome events or summary measures
16(a)
Main results
Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included
16(b)
Main results
Report category boundaries when continuous variables were categorized
16(c)
Main results
If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period
17
Other analyses
Report other analyses done—eg analyses of subgroups and interactions, and sensitivity analyses

Discussion

18
Key results
Summarise key results with reference to study objectives
19
Limitations
Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias
20
Interpretation
Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar studies, and other relevant evidence
21
Generalisability
Discuss the generalisability (external validity) of the study results

Other information

22
Funding
Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based

*Give information separately for cases and controls in case-control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies.

An Explanation and Elaboration article discusses each checklist item and gives methodological background and published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article.

Your answers stay in this browser. Nothing is sent to a server.

What the STROBE checklist covers

STROBE, Strengthening the Reporting of Observational Studies in Epidemiology, lists 22 things a report of an observational study should contain: from naming the design in the title (item 1) to describing the funding (item 22). It applies to the three main observational designs: cohort, case-control and cross-sectional studies.

The checklist was published in 2007 in PLoS Medicine, Annals of Internal Medicine, the BMJ, Epidemiology and other journals, together with an explanation and elaboration paper that gives the reasoning and published examples for each item. Eighteen items are common to all designs. The other four change with the design, and the tool above shows only the wording for the design you choose.

For a walk-through of the items reviewers check most, read our practical guide to the STROBE checklist.

Items that differ by study design

STROBE items with wording specific to cohort, case-control and cross-sectional studies
Item	Cohort	Case-control	Cross-sectional
6(a) Participants	Eligibility, sources and selection of participants; methods of follow-up	Case ascertainment and control selection, and why those cases and controls	Eligibility, sources and selection of participants
6(b) Matching	Matching criteria and number of exposed and unexposed	Matching criteria and number of controls per case	Does not apply
12(d) Statistical methods	How loss to follow-up was addressed	How matching of cases and controls was addressed	Analysis that accounts for the sampling strategy
14(c) Descriptive data	Follow-up time (average and total)	Does not apply	Does not apply
15 Outcome data	Outcome events or summary measures over time	Numbers in each exposure category	Outcome events or summary measures

Items 8, 13, 14 and 15 carry an asterisk: give the information separately for cases and controls, or for exposed and unexposed groups where that applies.

How to complete and submit it

Finish the manuscript first. The checklist points to places in the text, so fill it in against the version you will submit.
Give a location for every item. Use the section and paragraph, page numbers, or both, as the journal asks. A blank cell looks like a missing item.
Explain anything not applicable. “Not applicable: unmatched design” is better than an empty cell or a bare “N/A”.
Download the Word file and upload it as a supplementary file, or paste the locations into the journal’s own form.
Say that you used STROBE in the methods, for example “This study is reported according to the STROBE statement”, and cite it.

Frequently asked questions

What is the STROBE checklist?: STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) is a 22-item checklist of what to report in a cohort, case-control or cross-sectional study. Eighteen items are the same for all three designs; items 6, 12, 14 and 15 have wording specific to each design. It was published in 2007 and is the reporting guideline most journals ask for with observational research.
Which STROBE checklist should I use: cohort, case-control, cross-sectional or combined?: Use the checklist for your design. The STROBE Initiative publishes separate versions for cohort, case-control and cross-sectional studies and a combined version with all three. Choose your design above and the tool shows only the wording that applies, for example how loss to follow-up was handled for a cohort study or how matching was handled for a case-control study.
How do I fill in the STROBE checklist?: For each item, find where your manuscript reports it and write the location, such as “Methods, Statistical analysis, p. 7”. If an item does not apply, for example matching in an unmatched study, mark it not applicable and say why. Upload the completed checklist as a supplementary file, and update the page numbers after revisions.
Is the STROBE checklist mandatory?: Many medical and public health journals require a completed STROBE checklist for observational studies, and others recommend it. Check the target journal’s instructions for authors. Even when it is optional, editors and reviewers often use the items to judge whether the methods and results are reported fully.
Is STROBE a quality or risk-of-bias assessment tool?: No. STROBE says what to report, not how good a study is. A well-reported study can still have serious bias. For appraising observational studies in a systematic review, use a risk-of-bias tool such as ROBINS-I or the Newcastle-Ottawa Scale instead.
What do the asterisks on items 8, 13, 14 and 15 mean?: They mark items where information should be given separately for cases and controls in case-control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies.
Does STROBE apply to retrospective studies and registry data?: Yes. Retrospective cohort studies and chart reviews are observational studies, so STROBE applies. If the study uses routinely collected health data, such as electronic health records, claims or registries, also use the RECORD extension, which adds items on data sources, linkage and code lists.
Which checklist should I use instead of STROBE?: Randomised trials use CONSORT, systematic reviews use PRISMA, diagnostic accuracy studies use STARD, prediction model studies use TRIPOD, case reports use CARE and qualitative studies use SRQR or COREQ. Mendelian randomisation studies use STROBE-MR.
Should I write page numbers or section names?: Follow the journal’s instructions. Page numbers change when a manuscript is reformatted, so many authors give the section and paragraph, for example “Methods, Participants, para 2”, or both. Whatever you choose, make sure the location still matches the final submitted file.
Are my answers stored anywhere?: No. The checklist runs in your browser and nothing is sent to a server. Your answers are kept in this browser’s local storage so they are still there when you come back; use “Clear answers” to remove them.

Sources

von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP; STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. PLoS Med 2007;4(10):e296. doi:10.1371/journal.pmed.0040296.
Vandenbroucke JP, von Elm E, Altman DG, et al. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration. PLoS Med 2007;4(10):e297.
STROBE Initiative. STROBE checklists for cohort, case-control and cross-sectional studies (version 4).
Benchimol EI, Smeeth L, Guttmann A, et al. The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement. PLoS Med 2015;12(10):e1001885.
Skrivankova VW, Richmond RC, Woolf BAR, et al. Strengthening the Reporting of Observational Studies in Epidemiology Using Mendelian Randomization: the STROBE-MR statement. JAMA 2021;326(16):1614–1621.
EQUATOR Network. STROBE reporting guideline.

Content updated November 1, 2026. This is an independent tool and is not affiliated with the STROBE Initiative. Check your target journal’s instructions for the form it requires.