Erik von ElmpersName, Douglas G. AltmanpersName, Matthias EggerpersName (2007date). “The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement.” PLOS Medicinetitle·j, BernplaceName.
Object of study — What an accurate and complete report of a cohortterm·key, case-controlterm or cross-sectionalterm·key study must contain.
Research question — Observationalterm·key research is often reported so incompletely that a reader cannot judge it - what minimum set of itemsterm·key would fix that?
Contribution — A 22-item checklistterm·mth, 18 itemsterm·key shared across three observationalterm·key designs and four design-specific, arrived at by workshop and iterative consultation.
phenomenon · claim-type · cross-domain-transfer · mechanism · claim-relation · replication-status · limitation — grounded in the full text| phenomenon | reporting quality of observational epidemiological studies — “The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability.” | |
| claim-type | method — “The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study.” | |
| method — evidence | — “We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items.” | |
| object of study — evidence | — “The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study.” | |
| research question — evidence | — “Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability.” | |
| contribution — evidence | — “The STROBE Statement is a checklist of 22 items that we consider essential for good reporting of observational studies” | |
| transfer | from epidemiology / statistics (observational study design): the epidemiological and statistical methodology of observational study designs (cohort, case-control, cross-sectional) and confounding control, standardized for transparent medical reporting — “We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies” | transfers[0] |
| mechanism | a reader can only assess a study from what is written down, so completeness of the report is the precondition for any critical assessment at all — “The credibility of research depends on a critical assessment by others of the strengths and weaknesses in study design, conduct, and analysis.” | mechanisms[0] |
| mechanism | the precedent is that a checklist actually works: CONSORT measurably improved the reporting of randomised trials — “Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials [ 14 , 15 ].” | mechanisms[1] |
| mechanism | adoption runs through journals rather than authors - editorial staff of seven journals sat in the room where the list was drafted — “23 individuals attended this meeting, including editorial staff from Annals of Internal Medicine , BMJ , Bulletin of the World Health Organization , International Journal of Epidemiology , JAMA , Preventive Medicine , and The Lancet, as well as epidemiologists, methodologists, statisticians, and practitioners from Europe and North America.” | mechanisms[2] |
| mechanism | A STANDARD MODELLED ON A STANDARD FROM A DIFFERENT STUDY DESIGN: `We developed the checklist through an open process, taking into account the experience gained with previous initiatives, in particular CONSORT.` Inheritance between guideline families, stated as method rather than as citation. — “We developed the checklist through an open process, taking into account the experience gained with previous initiatives, in particular CONSORT” | mechanisms[3] |
| mechanism | AND THE REVISION IS PROMISED BEFORE ANY EVIDENCE FOR IT EXISTS: `We will revise the checklist in the future, taking into account comments, criticism, new evidence, and experience from its use.` A standing commitment to revise, made in the founding document - which is what MISEV, CONSORT and EWGSOP all later did without having said so in advance. — “We will revise the checklist in the future, taking into account comments, criticism, new evidence, and experience from its use” | mechanisms[4] |
| builds-on | the CONSORT Statement for reporting randomised trials — “We developed the checklist through an open process, taking into account the experience gained with previous initiatives, in particular CONSORT.” | claim_relations[0] |
| builds-on | the CONSORT Statement for randomised trials [ 12 ] — “The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ].” | claim_relations[1] |
| extends | empirical surveys of reporting deficiencies in epidemiology, psychiatry and stroke research — “In a survey of longitudinal studies in stroke research, 17 of 49 articles (35%) did not specify the eligibility criteria [ 8 ].” | claim_relations[2] |
| sense | quality - of the REPORT: whether a reader can follow what was planned, done and found. This is what STROBE addresses — “Research should be reported transparently so that readers can follow what was planned, what was done, what was found, and what conclusions were drawn.” | senses[0] |
| sense | quality - of the RESEARCH itself: how good the study is. The paper states explicitly that the checklist does not measure this — “Also, while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research.” | senses[1] |
| sense | guidance - on how to WRITE UP a study, as opposed to guidance on how to design or conduct one — “The intention is solely to provide guidance on how to report observational research well: these recommendations are not prescriptions for designing or conducting studies.” | senses[2] |
| sense | A REPORTING STANDARD THAT DISCLAIMS STANDARDISATION: `We do not aim at standardising reporting.` The document is a checklist of what must be present, and it explicitly refuses to prescribe the form - a distinction the field routinely collapses. — “We do not aim at standardising reporting” | senses[3] |
| sense | Analytical epidemiology - domain here represented by cohort, case-control, and cross-sectional designs — “The STROBE Statement is a checklist of items that should be addressed in articles reporting on the 3 main study designs of analytical epidemiology: cohort, case-control, and cross-sectional studies” | senses[4] |
| sense | Case-control / cross-sectional studies - two of STROBE's three principal analytical observational designs — “The STROBE Statement is a checklist of items that should be addressed in articles reporting on the 3 main study designs of analytical epidemiology: cohort, case-control, and cross-sectional studies” | senses[5] |
| sense | Reporting recommendations - guidance that can improve reporting quality rather than prescribe study conduct — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | senses[6] |
| sense | CONSORT - prior reporting initiative credited with improving randomized-trial reports — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | senses[7] |
| sense | Potential confounders - variables to define explicitly alongside outcomes, exposures, predictors, and effect modifiers — “Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable” | senses[8] |
| sense | Effect modifiers - effect-varying variables that reports should define clearly — “Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable” | senses[9] |
| sense | Statistical methods - analysis, confounding-control, subgroup, interaction, missing-data, and design-specific procedures — “Describe all statistical methods, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing data were addressed (d) 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 (e) Describe any sensitivity analyses” | senses[10] |
| sense | Sensitivity analyses - robustness analyses whose performance should be reported — “Describe all statistical methods, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing data were addressed (d) 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 (e) Describe any sensitivity analyses” | senses[11] |
| sense | Unadjusted versus confounder-adjusted estimates - both forms, their precision, and adjustment rationale belong in main results — “Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period” | senses[12] |
| sense | Relative versus absolute risk - relative estimates may be translated into time-bounded absolute effects — “Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period” | senses[13] |
| sense | Generalisability / external validity - applicability of the study results beyond the observed sample and setting — “Discuss the generalisability (external validity) of the study results” | senses[14] |
| sense | Standardising reporting - rigid-format goal explicitly disclaimed by STROBE — “The STROBE Statement should not be interpreted as an attempt to prescribe the reporting of observational research in a rigid format. The checklist items should be addressed in sufficient detail and with clarity somewhere in an article, but the order and format for presenting information depends on author preferences, journal style, and the traditions of the research field. For instance, we discuss the reporting of results under a number of separate items, while recognizing that authors might address several items within a single section of text or in a table. Also, item 22, on the source of funding and the role of funders, could be addressed in an appendix or in the methods section of the article. We do not aim at standardising reporting” | senses[15] |
| sense | STROBEd - rejected verb meaning regulation of a manuscript's style or terminology — “We believe that manuscripts should not be “STROBEd”, in the sense of regulating style or terminology” | senses[16] |
| sense | Good reporting - a property separable from whether the reported research itself was good — “we used several examples of good reporting from studies whose results were not confirmed in further research – the important feature was the good reporting, not whether the research was of good quality” | senses[17] |
| sense | Clarity of reporting - prerequisite for evaluation, not itself an evaluation instrument — “while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research” | senses[18] |
| sense | Evolving documents - reporting recommendations requiring ongoing assessment, refinement, and change — “STROBE and other recommendations on the reporting of research should be seen as evolving documents that require continual assessment, refinement, and, if necessary, change” | senses[19] |
| edge | STROBE —is-a→ checklist — “The STROBE Statement is a checklist of 22 items that we consider essential for good reporting of observational studies” | concept_edges[0] |
| audit | STROBE —distinct-from→ instrument to evaluate the quality of observational research — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but endpoint by anaphora: 'the checklist' = the STROBE Statement checklist (previous sentences). — “Also, while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research.” | concept_edges[1] |
| audit | STROBE —distinct-from→ prescriptions for designing or conducting studies — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but endpoint by anaphora: 'these recommendations' = the STROBE Statement (previous sentences). — “The intention is solely to provide guidance on how to report observational research well: these recommendations are not prescriptions for designing or conducting studies.” | concept_edges[2] |
| audit | STREGA —part-of→ STROBE — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span calls STREGA an EXTENSION to STROBE; part-of is loose. — “A first extension to STROBE is underway for gene-disease association studies: the STROBE Extension to Genetic Association studies (STREGA) initiative [ 25 ].” | concept_edges[3] |
| note | STREGA —part-of→ STROBE — the paper says 'extension to STROBE'. An extension is a derivative rather than a component; part-of is the nearest of the eight and the fit is loose. — “A first extension to STROBE is underway for gene-disease association studies: the STROBE Extension to Genetic Association studies (STREGA) initiative [ 25 ].” | concept_edges[3] |
| weight | STREGA —part-of→ STROBE — 0.8 — “A first extension to STROBE is underway for gene-disease association studies: the STROBE Extension to Genetic Association studies (STREGA) initiative [ 25 ].” | concept_edges[3] |
| audit | observational studies —contrasted-with→ randomised trials — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but endpoint by anaphora: the span continues 'Randomised trials cannot answer all important questions ... For example,' (previous sentence). — “observational studies are more suitable to detect rare or late adverse effects of treatments, and are more likely to provide an indication of what is achieved in daily medical practice [ 3 ]” | concept_edges[4] |
| audit | Recommendations on the reporting of research —causes→ reporting quality — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says recommendations CAN improve reporting quality; hedged. — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concept_edges[5] |
| note | Recommendations on the reporting of research —causes→ reporting quality — The paper states directly that recommendations can improve reporting quality; 'can' describes capability, so the paper's claim is retained at weight 1.0. — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concept_edges[5] |
| note | CONSORT —causes→ quality of reports of randomised trials — The paper credits the CONSORT initiative with having improved the quality of randomized-trial reports. — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concept_edges[6] |
| audit | STROBE —distinct-from→ standardising reporting — Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span says STROBE is not a rigid format; distinct-from 'standardising reporting' paraphrases that. — “The STROBE Statement should not be interpreted as an attempt to prescribe the reporting of observational research in a rigid format. The checklist items should be addressed in sufficient detail and with clarity somewhere in an article, but the order and format for presenting information depends on author preferences, journal style, and the traditions of the research field. For instance, we discuss the reporting of results under a number of separate items, while recognizing that authors might address several items within a single section of text or in a table. Also, item 22, on the source of funding and the role of funders, could be addressed in an appendix or in the methods section of the article. We do not aim at standardising reporting” | concept_edges[7] |
| note | STROBE —distinct-from→ standardising reporting — The paper explicitly says STROBE should not be interpreted as rigid prescription and does not aim at standardizing reporting. — “The STROBE Statement should not be interpreted as an attempt to prescribe the reporting of observational research in a rigid format. The checklist items should be addressed in sufficient detail and with clarity somewhere in an article, but the order and format for presenting information depends on author preferences, journal style, and the traditions of the research field. For instance, we discuss the reporting of results under a number of separate items, while recognizing that authors might address several items within a single section of text or in a table. Also, item 22, on the source of funding and the role of funders, could be addressed in an appendix or in the methods section of the article. We do not aim at standardising reporting” | concept_edges[7] |
| note | generalisability —same-as→ external validity — The checklist gives external validity as the parenthetical name for generalisability. — “Discuss the generalisability (external validity) of the study results” | concept_edges[8] |
| note | good reporting —distinct-from→ research was of good quality — The paper marks good reporting as the important feature, not whether the underlying research was good. — “we used several examples of good reporting from studies whose results were not confirmed in further research – the important feature was the good reporting, not whether the research was of good quality” | concept_edges[9] |
| for which use | limitation — the gap the statement addresses: IN PUBLISHED OBSERVATIONAL RESEARCH IMPORTANT INFORMATION IS OFTEN MISSING OR UNCLEAR — “in published observational research important information is often missing or unclear” | limitations[0] |
| for which use | limitation — the designs it covers: STROBE IS CURRENTLY LIMITED TO THREE MAIN OBSERVATIONAL STUDY DESIGNS — “We acknowledge that STROBE is currently limited to three main observational study designs.” | limitations[1] |
| for which use | limitation — the evidential basis of the checklist items themselves: WE DID NOT UNDERTAKE A COMPREHENSIVE SYSTEMATIC REVIEW FOR EACH OF THE CHECKLIST ITEMS AND SUB-ITEMS, OR DO OUR OWN RESEARCH TO FILL GAPS IN THE EVIDENCE BASE — “We did not undertake a comprehensive systematic review for each of the checklist items and sub-items, or do our own research to fill gaps in the evidence base.” | limitations[2] |
| for which use | limitation — the authority of the recommendations: THE COMPOSITION OF THE GROUP OF CONTRIBUTORS WAS INFLUENCED BY EXISTING NETWORKS AND WAS NOT REPRESENTATIVE IN TERMS OF GEOGRAPHY — “Further, although no one was excluded from the process, the composition of the group of contributors was influenced by existing networks and was not representative in terms of geography (it was dominated by contributors from Europe and North America) and probably was not representative in terms of research interests and disciplines.” | limitations[3] |
| for which use | limitation — quality appraisal, which the authors rule out as CONSORT does: the checklist is not a quality-assessment instrument for observational research — “We emphasise that the STROBE Statement was not developed as a tool for assessing the quality of published observational research.” | limitations[4] |
| for which use | limitation — the same scope as limitations[1] - the checklist covers three observational designs, and case-crossover and ecological studies are outside it — “We acknowledge that STROBE is currently limited to three main observational study designs.” | limitations[5] |
| for which use | limitation — any use of the statement as a prescribed format: THE STROBE STATEMENT SHOULD NOT BE INTERPRETED AS AN ATTEMPT TO PRESCRIBE THE REPORTING OF OBSERVATIONAL RESEARCH IN A RIGID FORMAT — “The STROBE Statement should not be interpreted as an attempt to prescribe the reporting of observational research in a rigid format.” | limitations[6] |
| for which use | limitation — any use of the checklist as a quality score: WHILE CLARITY OF REPORTING IS A PREREQUISITE TO EVALUATION, THE CHECKLIST IS NOT AN INSTRUMENT TO EVALUATE THE QUALITY OF OBSERVATIONAL RESEARCH — “Also, while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research.” | limitations[7] |
| replication | untested | |
| no type for this | clarity of reporting → evaluation — Clarity of reporting is a prerequisite for evaluation. Prerequisite-for is not is-a, part-of, same-as, distinct-from, contrasted-with, operationalised-as, causes, or renamed-across-fields. — “while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research” | unhoused_relations[0] |
| limitation | in published observational research important information is often missing or unclear (the gap STROBE addresses) — “in published observational research important information is often missing or unclear” | limitations[0] |
| limitation | STROBE covers only three observational designs and does not yet extend to others such as case-crossover or ecological studies. — “We acknowledge that STROBE is currently limited to three main observational study designs.” | limitations[1] |
| limitation | No comprehensive systematic review was done for the individual checklist items and no new research was conducted to fill evidence gaps. — “We did not undertake a comprehensive systematic review for each of the checklist items and sub-items, or do our own research to fill gaps in the evidence base.” | limitations[2] |
| limitation | The group of contributors was shaped by existing networks and was not geographically or disciplinarily representative. — “Further, although no one was excluded from the process, the composition of the group of contributors was influenced by existing networks and was not representative in terms of geography (it was dominated by contributors from Europe and North America) and probably was not representative in terms of research interests and disciplines.” | limitations[3] |
| limitation | The checklist is explicitly not a quality-assessment instrument for observational research. — “We emphasise that the STROBE Statement was not developed as a tool for assessing the quality of published observational research.” | limitations[4] |
| limitation | Covers only three observational designs; case-crossover and ecological studies are outside it. — “We acknowledge that STROBE is currently limited to three main observational study designs.” | limitations[5] |
| limitation | The authors explicitly disclaim rigidity and standardisation - the items must be addressed somewhere, in any order or format. — “The STROBE Statement should not be interpreted as an attempt to prescribe the reporting of observational research in a rigid format.” | limitations[6] |
| limitation | The checklist is not a quality-assessment instrument, and the paper says so to forestall exactly that use. — “Also, while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research.” | limitations[7] |
finding · quantity · variable · definition · key-term — grounded in the full text| finding | The reporting of such research is often inadequate, hampering assessment of its strengths, weaknesses and generalisability. — “The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability” | content_tags.findings[0] |
| evidence status note | finding — QUOTE RECOVERED FROM THE PAPER'S OWN CHARACTERS. The recorded quote was LETTERS-ONLY IDENTICAL to this stretch of the staged text but not an exact substring of it - spaces, hyphens, ligature glyphs or mathematical operators differed, so it could never anchor. This is the file's own text between the same two letters: not produced by a rule about the damage, copied out of the file. Round-trip checked (the recovered span is letters-only equal to the original) and length-checked. The text as originally recorded is kept in evidence as extracted. | content_tags.findings[0] |
| finding | Research should be reported transparently so readers can follow what was planned, done, found, and concluded. — “Research should be reported transparently so that readers can follow what was planned, what was done, what was found, and what conclusions were drawn” | content_tags.findings[1] |
| finding | The checklist is 22 items: 18 common to all three designs, four design-specific. — “18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies.” | content_tags.findings[2] |
| finding | The problem is documented, not assumed: 35% of longitudinal stroke studies did not state their eligibility criteria. — “In a survey of longitudinal studies in stroke research, 17 of 49 articles (35%) did not specify the eligibility criteria [ 8 ].” | content_tags.findings[3] |
| finding | The rationale behind the choice of potential confounding variables was often not reported. — “An analysis of epidemiological studies published in general medical and specialist journals found that the rationale behind the choice of potential confounding variables was often not reported [ 6 ].” | content_tags.findings[4] |
| finding | Few reports of case-control studies in psychiatry explained the methods used to identify cases and controls. — “Only few reports of case-control studies in psychiatry explained the methods used to identify cases and controls [ 7 ].” | content_tags.findings[5] |
| quantity | 22 items — number of checklist items in the STROBE Statement — “resulted in a checklist of 22 items (the STROBE Statement)” | content_tags.quantities[0] |
| quantity | three study designs — designs covered: cohort, case-control, cross-sectional — “to cover three main study designs: cohort, case-control” | content_tags.quantities[1] |
| quantity | 22 items — size of the checklist — “The STROBE Statement is a checklist of 22 items that we consider essential for good reporting of observational studies” | content_tags.quantities[2] |
| quantity | 18 common, 4 design-specific — how the checklist splits across the three designs — “18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies.” | content_tags.quantities[3] |
| quantity | 17 of 49 articles (35%) — longitudinal stroke studies that did not specify eligibility criteria — “In a survey of longitudinal studies in stroke research, 17 of 49 articles (35%) did not specify the eligibility criteria [ 8 ].” | content_tags.quantities[4] |
| quantity | 23 individuals — attendance at the workshop that drafted the checklist — “23 individuals attended this meeting, including editorial staff from Annals of Internal Medicine , BMJ , Bulletin of the World Health Organization , International Journal of Epidemiology , JAMA , Preventive Medicine , and The Lancet, as well as epidemiologists, methodologists, statisticians, and practitioners from Europe and North America.” | content_tags.quantities[5] |
| definition | STROBE Statement — “a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results, and discussion sections” | content_tags.definitions[0] |
| definition | observational study designs — “three main study designs: cohort, case-control, and cross-sectional studies” | content_tags.definitions[1] |
| definition | the STROBE Statement — “The STROBE Statement is a checklist of 22 items that we consider essential for good reporting of observational studies” | content_tags.definitions[2] |
| definition | transparent reporting — “Research should be reported transparently so that readers can follow what was planned, what was done, what was found, and what conclusions were drawn.” | content_tags.definitions[3] |
| key-terms | reporting, observational, studies, checklist, STROBE, recommendations, epidemiology, transparent, items, observational studies, cohort, case-control, cross-sectional, CONSORT, STREGA, randomised trials, transparent reporting, systematic reviews, confounding variables |
| concept | STROBE — not defined in this paper's own words; a 22-item checklist of what a report of an observational study must contain — “The STROBE Statement is a checklist of 22 items that we consider essential for good reporting of observational studies” | concepts[4] |
| concept | checklist — not defined in this paper's own words; an enumerated list of items a report must address, used as a reporting standard rather than as a scoring instrument — “The STROBE Statement is a checklist of 22 items that we consider essential for good reporting of observational studies” | concepts[5] |
| concept | observational studies — not defined in this paper's own words; research that observes rather than assigns exposure - here restricted to the three analytical designs — “We decided to focus on the 3 study designs that are used most widely in analytical observational research: cohort, case-control, and cross-sectional studies.” | concepts[6] |
| concept | randomised trials — not defined in this paper's own words; the assignment-based design that observational studies complement rather than replace — “Randomised trials cannot answer all important questions about a given intervention.” | concepts[7] |
| concept | CONSORT — not defined in this paper's own words; the earlier reporting standard for randomised trials, taken as the model and the evidence that checklists work — “The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ].” | concepts[8] |
| concept | STREGA — not defined in this paper's own words; the extension of STROBE to gene-disease association studies — “A first extension to STROBE is underway for gene-disease association studies: the STROBE Extension to Genetic Association studies (STREGA) initiative [ 25 ].” | concepts[9] |
| concept | transparent reporting — not defined in this paper's own words; writing a study up so a reader can follow what was planned, done, found and concluded — “Research should be reported transparently so that readers can follow what was planned, what was done, what was found, and what conclusions were drawn.” | concepts[10] |
| concept | instrument to evaluate the quality of observational research — not defined in this paper's own words; a scoring tool for judging how good a study is - which the paper states the checklist is NOT — “Also, while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research.” | concepts[11] |
| concept | prescriptions for designing or conducting studies — not defined in this paper's own words; rules about how research should be done - which the paper states the recommendations are NOT — “The intention is solely to provide guidance on how to report observational research well: these recommendations are not prescriptions for designing or conducting studies.” | concepts[12] |
| concept | confounding variables — not defined in this paper's own words; the variables adjusted for, whose selection rationale is one of the things routinely left unreported — “An analysis of epidemiological studies published in general medical and specialist journals found that the rationale behind the choice of potential confounding variables was often not reported [ 6 ].” | concepts[13] |
| concept | CONSORT — not defined in this paper's own words; the trials checklist this one is modelled on - dated here as 1996 and revised five years later, which is the same chain schulz2010 continues in 2010 — “The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concepts[14] |
| concept | analytical epidemiology — not defined in this paper's own words; the epidemiological domain whose three principal designs the checklist addresses — “The STROBE Statement is a checklist of items that should be addressed in articles reporting on the 3 main study designs of analytical epidemiology: cohort, case-control, and cross-sectional studies” | concepts[15] |
| concept | case-control — not defined in this paper's own words; one of STROBE's three principal analytical observational designs — “The STROBE Statement is a checklist of items that should be addressed in articles reporting on the 3 main study designs of analytical epidemiology: cohort, case-control, and cross-sectional studies” | concepts[16] |
| concept | cross-sectional studies — not defined in this paper's own words; one of STROBE's three principal analytical observational designs — “The STROBE Statement is a checklist of items that should be addressed in articles reporting on the 3 main study designs of analytical epidemiology: cohort, case-control, and cross-sectional studies” | concepts[17] |
| concept | analytical observational research — not defined in this paper's own words; the research class for which cohort, case-control, and cross-sectional designs are most widely used — “We decided to focus on the 3 study designs that are used most widely in analytical observational research: cohort, case-control, and cross-sectional studies” | concepts[18] |
| concept | Recommendations on the reporting of research — not defined in this paper's own words; recommendations presented as capable of improving how research is reported — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concepts[19] |
| concept | reporting quality — not defined in this paper's own words; quality of reporting that recommendations can improve — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concepts[20] |
| concept | quality of reports of randomised trials — not defined in this paper's own words; quality of randomized-trial reports improved by the CONSORT initiative — “Recommendations on the reporting of research can improve reporting quality. The Consolidated Standards of Reporting Trials (CONSORT) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trials” | concepts[21] |
| concept | potential confounders — not defined in this paper's own words; variables that reports should define clearly alongside outcomes, exposures, predictors, and modifiers — “Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable” | concepts[22] |
| concept | effect modifiers — not defined in this paper's own words; variables modifying effects that should be clearly defined in a report — “Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable” | concepts[23] |
| concept | statistical methods — not defined in this paper's own words; analysis procedures that should be reported, including confounding control and subgroup methods — “Describe all statistical methods, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing data were addressed (d) 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 (e) Describe any sensitivity analyses” | concepts[24] |
| concept | missing data — not defined in this paper's own words; absent observations whose handling the report must explain — “Describe all statistical methods, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing data were addressed (d) 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 (e) Describe any sensitivity analyses” | concepts[25] |
| concept | loss to follow-up — not defined in this paper's own words; cohort attrition whose handling should be reported — “Describe all statistical methods, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing data were addressed (d) 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 (e) Describe any sensitivity analyses” | concepts[26] |
| concept | sensitivity analyses — not defined in this paper's own words; additional analyses whose performance should be described — “Describe all statistical methods, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing data were addressed (d) 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 (e) Describe any sensitivity analyses” | concepts[27] |
| concept | unadjusted estimates — not defined in this paper's own words; raw effect estimates that the main-results item asks authors to give — “Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period” | concepts[28] |
| concept | confounder-adjusted estimates — not defined in this paper's own words; estimates adjusted for confounders, with the chosen confounders made explicit — “Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period” | concepts[29] |
| concept | relative risk — not defined in this paper's own words; relative effect measure that may be translated into absolute risk — “Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period” | concepts[30] |
| concept | absolute risk — not defined in this paper's own words; time-bounded absolute effect measure translated from relative risk when relevant — “Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period” | concepts[31] |
| concept | generalisability — not defined in this paper's own words; applicability of study results beyond the observed setting — “Discuss the generalisability (external validity) of the study results” | concepts[32] |
| concept | external validity — not defined in this paper's own words; the parenthetical name the checklist gives for generalisability — “Discuss the generalisability (external validity) of the study results” | concepts[33] |
| concept | standardising reporting — not defined in this paper's own words; rigid reporting standardization that STROBE explicitly disclaims — “The STROBE Statement should not be interpreted as an attempt to prescribe the reporting of observational research in a rigid format. The checklist items should be addressed in sufficient detail and with clarity somewhere in an article, but the order and format for presenting information depends on author preferences, journal style, and the traditions of the research field. For instance, we discuss the reporting of results under a number of separate items, while recognizing that authors might address several items within a single section of text or in a table. Also, item 22, on the source of funding and the role of funders, could be addressed in an appendix or in the methods section of the article. We do not aim at standardising reporting” | concepts[34] |
| concept | STROBEd — not defined in this paper's own words; the rejected verb for regulating manuscript style or terminology through STROBE — “We believe that manuscripts should not be “STROBEd”, in the sense of regulating style or terminology” | concepts[35] |
| concept | regulating style or terminology — not defined in this paper's own words; the style-and-terminology control intended by the paper's rejected sense of 'STROBEd' — “We believe that manuscripts should not be “STROBEd”, in the sense of regulating style or terminology” | concepts[36] |
| concept | good reporting — not defined in this paper's own words; clarity and completeness of a report, separable from whether the underlying research is good — “we used several examples of good reporting from studies whose results were not confirmed in further research – the important feature was the good reporting, not whether the research was of good quality” | concepts[37] |
| concept | research was of good quality — not defined in this paper's own words; quality of the underlying study, explicitly distinguished from quality of its reporting — “we used several examples of good reporting from studies whose results were not confirmed in further research – the important feature was the good reporting, not whether the research was of good quality” | concepts[38] |
| concept | clarity of reporting — not defined in this paper's own words; reporting property stated to be necessary before evaluation is possible — “while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research” | concepts[39] |
| concept | evaluation — not defined in this paper's own words; assessment enabled by clear reporting but not performed by the STROBE checklist itself — “while clarity of reporting is a prerequisite to evaluation, the checklist is not an instrument to evaluate the quality of observational research” | concepts[40] |
| concept | evolving documents — not defined in this paper's own words; recommendations requiring continual assessment, refinement, and possible change — “STROBE and other recommendations on the reporting of research should be seen as evolving documents that require continual assessment, refinement, and, if necessary, change” | concepts[41] |
| confidence-interval CI | — “Report numbers of outcome events or summary measures (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval).” | content_tags.statistics[0] |
| odds-ratio OR | as written: relative risk — “category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period Report other analyses done—e.g., analyses of subgroups and interactions” | content_tags.statistics[1] |
| claim type | method — a second reading reaching the same value; recorded: method — “The intention is solely to provide guidance on how to report observational research well: these recommendations are not prescriptions for designing or conducting studies.” | alternatives.claim_type |
| method | system-or-tool-building — a second reading DIFFERING from the recorded value; recorded: expert-consensus — “We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items.” | alternatives.method |
| phenomenon | incomplete reporting of observational studies, and its remedy by checklist — a second reading DIFFERING from the recorded value; recorded: reporting quality of observational epidemiological studies — “However, in published observational research important information is often missing or unclear.” | alternatives.phenomenon |
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The Strengthening the Reportingterm·key of Observational Studiesterm·dom in Epidemiologyterm·dom (STROBEterm·mth) Statement: Guidelines for Reportingterm·key Observational Studiesterm·dom | PLOS Medicine Article Authors Metrics Comments Media Coverage Reader Comments Figures Figures Abstract Much biomedical research is observationalterm·key. The reportingterm·key of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisabilityterm. The Strengthening the Reportingterm·key of Observational Studiesterm·dom in Epidemiologyterm·dom (STROBEterm·mth) Initiative developed recommendationsterm·key on what should be included in an accurate and complete report of an observational studyterm·dom. We defined the scope of the recommendationsterm·key to cover three main study designs: cohortterm·key, case-controlterm, and cross-sectional studiesterm. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklistterm·mth of itemsterm·key. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBEterm·mth contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklistterm·mth of 22 itemsterm·key (the STROBE Statementterm·def) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 itemsterm·key are common to all three study designs and four are specific for cohortterm·key, case-controlterm, or cross-sectional studiesterm. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiologyterm·dom. We hope that the STROBE Statementterm·def will contribute to improving the quality of reportingterm·key of observational studiesterm·dom.
Citation: von ElmpersName E, AltmanpersName DG, EggerpersName M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP, et al. (2007) The Strengthening the Reportingterm·key of Observational Studiesterm·dom in Epidemiologyterm·dom (STROBEterm·mth) Statement: Guidelines for Reportingterm·key Observational Studiesterm·dom. PLoS Med 4(10): e296.
https://doi.org/10.1371/journal.pmed.0040296 Received: June 20, 2007; Accepted: August 30, 2007; Published: October 16, 2007 Copyright: © 2007 von ElmpersName et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For details on further use, see the STROBEterm·mth Web site (http://www.strobe-statement.org/). In order to encourage dissemination of the STROBE Statementterm·def, this article will also be published and made freely available by Annals of Internal Medicine, BMJ, Bulletin of the World Health Organization, Epidemiologyterm·dom, The Lancet, and Preventive Medicine.
Funding: The workshop was funded by the European Science Foundation (ESF). Additional funding was received from the Medical Research Council Health Services Research Collaboration and the National Health Services Research and Development Methodology Programme. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: CONSORTterm·mth, Consolidated Standards of Reportingterm·key Trials; STREGAterm·mth, STROBEterm·mth Extension to Genetic Association Studiesterm·key; STROBEterm·mth, Strengthening the Reportingterm·key of Observational Studiesterm·dom in Epidemiologyterm·dom Introduction Many questions in medical research are investigated in observational studiesterm·dom [ 1 ]. Much of the research into the cause of diseases relies on cohortterm·key, case-controlterm, or cross-sectional studiesterm. Observational studiesterm·dom also have a role in research into the benefits and harms of medical interventions [ 2 ]. Randomised trialsterm·mth cannot answer all important questions about a given intervention. For example, observational studiesterm·dom are more suitable to detect rare or late adverse effects of treatments, and are more likely to provide an indication of what is achieved in daily medical practice [ 3 ].
Research should be reported transparently so that readers can follow what was planned, what was done, what was found, and what conclusions were drawn. The credibility of research depends on a critical assessment by others of the strengths and weaknesses in study design, conduct, and analysis. Transparent reportingterm·dom is also needed to judge whether and how results can be included in systematic reviewsterm·key [ 4 , 5 ]. However, in published observationalterm·key research important information is often missing or unclear. An analysis of epidemiological studiesterm·key published in general medical and specialist journals found that the rationale behind the choice of potential confounding variablesterm·dom was often not reported [ 6 ]. Only few reports of case-controlterm studiesterm·key in psychiatry explained the methods used to identify cases and controls [ 7 ]. In a survey of longitudinal studiesterm·key in stroke research, 17 of 49 articles (35%) did not specify the eligibility criteria [ 8 ]. Others have argued that without sufficient clarity of reportingterm, the benefits of research might be achieved more slowly [ 9 ], and that there is a need for guidance in reportingterm·key observational studiesterm·dom [ 10 , 11 ].
Recommendations on the reporting of researchterm can improve reporting qualityterm. The Consolidated Standards of Reportingterm·key Trials (CONSORTterm·mth) Statement was developed in 1996 and revised 5 years later [ 12 ]. Many medical journals supported this initiative [ 13 ], which has helped to improve the quality of reports of randomised trialsterm [ 14 , 15 ]. Similar initiatives have followed for other research areas—e.g., for the reportingterm·key of meta-analyses of randomised trialsterm·mth [ 16 ] or diagnostic studiesterm·key [ 17 ]. We established a network of methodologists, researchers, and journal editors to develop recommendationsterm·key for the reportingterm·key of observationalterm·key research: the Strengthening the Reportingterm·key of Observational Studiesterm·dom in Epidemiologyterm·dom (STROBEterm·mth) Statement.
Aims and Use of the STROBE Statementterm·def The STROBE Statementterm·def is a checklistterm·mth of itemsterm·key that should be addressed in articles reportingterm·key on the 3 main study designs of analytical epidemiologyterm: cohortterm·key, case-controlterm, and cross-sectional studiesterm. The intention is solely to provide guidance on how to report observationalterm·key research well: these recommendationsterm·key are not prescriptions for designing or conducting studiesterm·mth. Also, while clarity of reportingterm is a prerequisite to evaluationterm, the checklistterm·mth is not an instrument to evaluate the quality of observational researchterm·mth.
Here we present the STROBE Statementterm·def and explain how it was developed. In a detailed companion paper, the Explanation and Elaboration article [ 18 – 20 ], we justify the inclusion of the different checklistterm·mth itemsterm·key and give methodological background and published examples of what we consider transparent reportingterm·dom. We strongly recommend using the STROBEterm·mth checklistterm·mth in conjunction with the explanatory article, which is available freely on the Web sites of PLoS Medicine ( http://www.plosmedicine.org/ ), Annals of Internal Medicine ( http://www.annals.org/ ), and Epidemiologyterm·dom ( http://www.epidem.com/ ).
Development of the STROBE Statementterm·def We established the STROBEterm·mth Initiative in 2004, obtained funding for a workshop and set up a Web site ( http://www.strobe-statement.org/ ). We searched textbooks, bibliographic databases, reference lists, and personal files for relevant material, including previous recommendationsterm·key, empirical studiesterm·key of reportingterm·key and articles describing relevant methodological research. Because observationalterm·key research makes use of many different study designs, we felt that the scope of STROBEterm·mth had to be clearly defined early on. We decided to focus on the 3 study designs that are used most widely in analytical observational researchterm: cohortterm·key, case-controlterm, and cross-sectional studiesterm.
We organised a 2-day workshop in Bristol, UK, in September 2004. 23 individuals attended this meeting, including editorial staff from Annals of Internal Medicine , BMJ , Bulletin of the World Health Organization , International Journal of Epidemiologyterm·dom , JAMA , Preventive Medicine , and The Lancet, as well as epidemiologists, methodologists, statisticians, and practitioners from Europe and North America. Written contributions were sought from 10 other individuals who declared an interest in contributing to STROBEterm·mth, but could not attend. Three working groups identified itemsterm·key deemed to be important to include in checkliststerm·mth for each type of study. A provisional list of itemsterm·key prepared in advance (available from our Web site) was used to facilitate discussions. The 3 draft checkliststerm·mth were then discussed by all participants and, where possible, itemsterm·key were revised to make them applicable to all three study designs. In a final plenary session, the group decided on the strategy for finalizing and disseminating the STROBE Statementterm·def.
After the workshop we drafted a combined checklistterm·mth including all three designs and made it available on our Web site. We invited participants and additional scientists and editors to comment on this draft checklistterm·mth. We subsequently published 3 revisions on the Web site, and 2 summaries of comments received and changes made. During this process the coordinating group (i.e., the authors of the present paper) met on eight occasions for 1 or 2 days and held several telephone conferences to revise the checklistterm·mth and to prepare the present paper and the Explanation and Elaboration paper [ 18 – 20 ]. The coordinating group invited 3 additional co-authors with methodological and editorial expertise to help write the Explanation and Elaboration paper, and sought feedback from more than 30 people, who are listed at the end of this paper. We allowed several weeks for comments on subsequent drafts of the paper and reminded collaborators about deadlines by e-mail.
STROBEterm·mth Components The STROBE Statementterm·def is a checklistterm·mth of 22 itemsterm·key that we consider essential for good reportingterm of observational studiesterm·dom ( Table 1 ). These itemsterm·key relate to the article's title and abstract (itemterm·key 1), the introduction (itemsterm·key 2 and 3), methods (itemsterm·key 4–12), results (itemsterm·key 13–17) and discussion sections (itemsterm·key 18–21), and other information (itemterm·key 22 on funding). 18 itemsterm·key are common to all three designs, while four (itemsterm·key 6, 12, 14, and 15) are design-specific, with different versions for all or part of the itemterm·key. For some itemsterm·key (indicated by asterisks), information should be given separately for cases and controls in case-controlterm studiesterm·key, or exposed and unexposed groups in cohortterm·key and cross-sectional studiesterm. Although presented here as a single checklistterm·mth, separate checkliststerm·mth are available for each of the 3 study designs on the STROBEterm·mth Web site.
Download: PNG larger image TIFF original image Table 1.
The STROBE Statementterm·def—Checklistterm·mth of Itemsterm·key That Should Be Addressed in Reports of Observational Studiesterm·dom https://doi.org/10.1371/journal.pmed.0040296.t001 Implications and Limitations The STROBE Statementterm·def was developed to assist authors when writing up analytical observational studiesterm·dom, to support editors and reviewers when considering such articles for publication, and to help readers when critically appraising published articles. We developed the checklistterm·mth through an open process, taking into account the experience gained with previous initiatives, in particular CONSORTterm·mth. We reviewed the relevant empirical evidence as well as methodological work, and subjected consecutive drafts to an extensive iterative process of consultation. The checklistterm·mth presented here is thus based on input from a large number of individuals with diverse backgrounds and perspectives. The comprehensive explanatory article [ 18 – 20 ], which is intended for use alongside the checklistterm·mth, also benefited greatly from this consultation process.
Observational studiesterm·dom serve a wide range of purposes, on a continuum from the discovery of new findings to the confirmation or refutation of previous findings [ 18 – 20 ]. Some studiesterm·key are essentially exploratory and raise interesting hypotheses. Others pursue clearly defined hypotheses in available data. In yet another type of studiesterm·key, the collection of new data is planned carefully on the basis of an existing hypothesis. We believe the present checklistterm·mth can be useful for all these studiesterm·key, since the readers always need to know what was planned (and what was not), what was done, what was found, and what the results mean. We acknowledge that STROBEterm·mth is currently limited to three main observational study designsterm·def. We would welcome extensions that adapt the checklistterm·mth to other designs—e.g., case-crossover studiesterm·key or ecological studiesterm·key—and also to specific topic areas. Four extensions are now available for the CONSORTterm·mth statement [ 21 – 24 ]. A first extension to STROBEterm·mth is underway for gene-disease association studiesterm·key: the STROBEterm·mth Extension to Genetic Association studiesterm·key (STREGAterm·mth) initiative [ 25 ]. We ask those who aim to develop extensions of the STROBE Statementterm·def to contact the coordinating group first to avoid duplication of effort.
The STROBE Statementterm·def should not be interpreted as an attempt to prescribe the reportingterm·key of observationalterm·key research in a rigid format. The checklistterm·mth itemsterm·key should be addressed in sufficient detail and with clarity somewhere in an article, but the order and format for presenting information depends on author preferences, journal style, and the traditions of the research field. For instance, we discuss the reportingterm·key of results under a number of separate itemsterm·key, while recognizing that authors might address several itemsterm·key within a single section of text or in a table. Also, itemterm·key 22, on the source of funding and the role of funders, could be addressed in an appendix or in the methods section of the article. We do not aim at standardising reportingterm. Authors of randomised clinical trials were asked by an editor of a specialist medical journal to “CONSORTterm·mth” their manuscripts on submission [ 26 ]. We believe that manuscripts should not be “STROBEdterm”, in the sense of regulating style or terminologyterm. We encourage authors to use narrative elements, including the description of illustrative cases, to complement the essential information about their study, and to make their articles an interesting read [ 27 ].
We emphasise that the STROBE Statementterm·def was not developed as a tool for assessing the quality of published observationalterm·key research. Such instruments have been developed by other groups and were the subject of a recent systematic reviewterm·key [ 28 ]. In the Explanation and Elaboration paper, we used several examples of good reportingterm from studiesterm·key whose results were not confirmed in further research – the important feature was the good reportingterm, not whether the research was of good qualityterm. However, if STROBEterm·mth is adopted by authors and journals, issues such as confounding, bias, and generalisabilityterm could become more transparentterm·key, which might help temper the over-enthusiastic reportingterm·key of new findings in the scientific community and popular media [ 29 ], and improve the methodology of studiesterm·key in the long term. Better reportingterm·key may also help to have more informed decisions about when new studiesterm·key are needed, and what they should address.
We did not undertake a comprehensive systematic reviewterm·key for each of the checklistterm·mth itemsterm·key and sub-items, or do our own research to fill gaps in the evidence base. Further, although no one was excluded from the process, the composition of the group of contributors was influenced by existing networks and was not representative in terms of geography (it was dominated by contributors from Europe and North America) and probably was not representative in terms of research interests and disciplines. We stress that STROBEterm·mth and other recommendations on the reporting of researchterm should be seen as evolving documentsterm that require continual assessment, refinement, and, if necessary, change. We welcome suggestions for the further dissemination of STROBEterm·mth—e.g., by re-publication of the present article in specialist journals and in journals published in other languages. Groups or individuals who intend to translate the checklistterm·mth to other languages should consult the coordinating group beforehand. We will revise the checklistterm·mth in the future, taking into account comments, criticism, new evidence, and experience from its use. We invite readers to submit their comments via the STROBEterm·mth Web site ( http://www.strobe-statement.org/ ).
Acknowledgments We are grateful to Gerd Antes, Kay Dickersin, Shah Ebrahim, and Richard Lilford for supporting the STROBEterm·mth Initiative. We are grateful to the following institutions that have hosted working meetings of the coordinating group: Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland; Department of Social Medicine, University of Bristol, Bristol, UK; London School of Hygiene and Tropical Medicine, London, UK; Nordic Cochrane Centre, Copenhagen, Denmark; and Centre for Statistics in Medicine, Oxford, UK. We are grateful to six reviewers who provided helpful comments on a previous draft of this paper.
Contributors to the STROBEterm·mth Initiative The following individuals have contributed to the content and elaboration of the STROBE Statementterm·def: Douglas G AltmanpersName, Maria Blettner, Paolo Boffetta, Hermann Brenner, Geneviève Chêne, Cyrus Cooper, George Davey-Smith, Erik von ElmpersName, Matthias EggerpersName, France Gagnon, Peter C Gøtzsche, Philip Greenland, Sander Greenland, Claire Infante-Rivard, John Ioannidis, Astrid James, Giselle Jones, Bruno Ledergerber, Julian Little, Margaret May, David Moher, Hooman Momen, Alfredo Morabia, Hal Morgenstern, Cynthia D Mulrow, Fred Paccaud, Stuart J Pocock, Charles Poole, Martin Röösli, Dietrich Rothenbacher, Kenneth Rothman, Caroline Sabin, Willi Sauerbrei, Lale Say, James J Schlesselman, Jonathan Sterne, Holly Syddall, Jan P Vandenbroucke, Ian White, Susan Wieland, Hywel Williams, Guang Yong Zou.
Author Contributions The authors coordinated the STROBEterm·mth Initiative and contributed to the writing of the paper. EvE wrote the first draft of the paper and takes care of most of the practical coordination of STROBEterm·mth. ME initiated STROBEterm·mth and, together with EvE, organised the first workshop.
NOT THE PAPER'S TEXT. Added by this project on 2026-08-25: the table below was restored from the held scrape because the staged text did not contain it, and document order is therefore not the paper's. [TABLE 1 RESTORED 2026-08-25 by terminal-a from fulltext.html - the staged body contained none of the 22 STROBE recommendations and the held scrape contains them. Found by META_CLAUDE (0 of 11 staged, 11 of 11 in the scrape) and by CLAUDE_B from the tag side (two live quotes already cut from this column, both ungrounded, both verbatim here). Verified independently: 0 of 9 probe items staged, 8 of 9 in the scrape. APPENDED AT THE END so no existing anchor offset moves; document order is therefore not the paper's.] Table 1. The STROBE Statementterm·def—Checklistterm·mth of Itemsterm·key That Should Be Addressed in Reports of Observational Studiesterm·dom Itemterm·key number Recommendationterm·key TITLE and ABSTRACT INTRODUCTION Background/ rationale Objectives METHODS Study design Setting Participants Variables Data sources/ measurement Bias Study size Quantitative variables Statistical methodsterm 4 5 6 7 8* 9 10 11 12 RESULTS Participants 13* Descriptive data 14* Outcome data 15* Main results Other analyses DISCUSSION Key results Limitations Interpretation Generalisabilityterm OTHER INFORMATION Funding 16 17 18 19 20 21 22 (a) Indicate the study’s design with a commonly used term in the title or the abstract (b) Provide in the abstract an informative and balanced summary of what was done and what was found Explain the scientific background and rationale for the investigation being reported State specific objectives, including any prespecified hypotheses Present key elements of study design early in the paper Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection (a) Cohort studyterm·mth—Give the eligibility criteria, and the sources and methods of selection of participants. Describe methods of follow-up Case-controlterm 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-sectionalterm·key study—Give the eligibility criteria, and the sources and methods of selection of participants (b) Cohort studyterm·mth—For matched studiesterm·key, give matching criteria and number of exposed and unexposed Case-controlterm study—For matched studiesterm·key, give matching criteria and the number of controls per case Clearly define all outcomes, exposures, predictors, potential confoundersterm, and effect modifiersterm. Give diagnostic criteria, if applicable 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 Describe any efforts to address potential sources of bias Explain how the study size was arrived at Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen, and why (a) Describe all statistical methodsterm, including those used to control for confounding (b) Describe any methods used to examine subgroups and interactions (c) Explain how missing dataterm were addressed (d) Cohort studyterm·mth—If applicable, explain how loss to follow-upterm was addressed Case-controlterm study—If applicable, explain how matching of cases and controls was addressed Cross-sectionalterm·key study—If applicable, describe analytical methods taking account of sampling strategy (e) Describe any sensitivity analysesterm (a) Report the numbers of individuals at each stage of the study—e.g., numbers potentially eligible, examined for eligibility, con- firmed eligible, included in the study, completing follow-up, and analysed (b) Give reasons for non-participation at each stage (c) Consider use of a flow diagram (a) Give characteristics of study participants (e.g., demographic, clinical, social) and information on exposures and potential con- foundersterm (b) Indicate the number of participants with missing dataterm for each variable of interest (c) Cohort studyterm·mth—Summarise follow-up time (e.g., average and total amount) Cohort studyterm·mth—Report numbers of outcome events or summary measures over time Case-controlterm study—Report numbers in each exposure category, or summary measures of exposure Cross-sectionalterm·key study—Report numbers of outcome events or summary measures (a) Give unadjusted estimatesterm and, if applicable, confounder-adjusted estimatesterm and their precision (e.g., 95% confidence intervalterm·stat). Make clear which confounders were adjusted for and why they were included (b) Report category boundaries when continuous variables were categorized (c) If relevant, consider translating estimates of relative riskterm into absolute riskterm for a meaningful time period Report other analyses done—e.g., analyses of subgroups and interactions, and sensitivity analysesterm Summarise key results with reference to study objectives Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar stu- diesterm·key, and other relevant evidence Discuss the generalisabilityterm (external validityterm) of the study results 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 such information separately for cases and controls in case-controlterm studiesterm·key, and, if applicable, for exposed and unexposed groups in cohortterm·key and cross-sectional studiesterm