The 22 Strobe Items and their sub-items
Items are labelled as XX# where XX represents the STROBE section [TA
(title and abstract), IN (introduction), ME (methods), RE (results), DI
(discussion)] and where # represents the STROBE item [1-22]. The
text is extracted from the STROBE explanatory article15and the lowercase alphanumerical listing [(a),
(b), (c), …] indicates the sub-items.
- TA1 Title and abstract. (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.
- IN2 Background/rationale. Explain the scientific background
and rationale for the investigation being reported.
- IN3 Objectives. State specific objectives, including any
prespecified hypotheses. (a) specific population, (b) exposures, (c)
outcomes, (d) parameter to be estimated.
- ME4 Methods. Study design. Present key elements of study
design early in the paper.
Cohort: (a1) cohort, (a2) time period, (a3) exposure status;
Case-control: (b1) case description, (b2) control description, (b3)
source, (b4) population;
Cross-sectional: (c1) population, (c2) timing.
- ME5 Setting. Describe the setting, locations, and relevant
dates, including periods of recruitment, exposure, follow-up, and data
collection.
- ME6 Participants.
Cohort: (a1) eligibility criteria, (a2) selection sources, (a3)
selection method, (a4) methods of follow-up
Matched Cohort: (a5) For matched studies, give matching criteria and
number of exposed and unexposed. Case-Controls: (b1) eligibility
criteria, (b2) selection sources, (b3) selection method, (b4)
rationale for the choice of cases and controls.
Matched Case-control study: (b5) For matched studies, give matching
criteria and the number of controls per case
Cross-sectional (c1) eligibility criteria, (c2) selection sources,
(c3) selection method
- ME7 Variables. Clearly define all (a) outcomes, (b) exposures
and predictors, (c) potential confounders and effect modifiers. Give
(d) diagnostic criteria, if applicable.
- ME8 Data sources/measurement. For each variable of interest,
give (a) sources of data and (b) details of methods of assessment
(measurement). Describe (c) comparability of assessment methods if
there is more than one group.
- ME9 Bias. Describe any efforts to address potential sources
of bias.
- ME10 Study size. Explain how the study size was arrived at.
- ME11 Quantitative variables. Explain how quantitative
variables were (a) handled in the analyses. If applicable, describe
(b) which groupings were chosen and why.
- ME12 Describe (a1) all statistical methods, including (a2)
those used to control for confounding. (b) Describe any methods used
to examine subgroups and interactions. (c) Explain how missing data
were addressed.
Cohort: (d1) If applicable, explain how loss to follow-up was
addressed.
Case-control: (d2) If applicable, explain how matching of cases and
controls was addressed.
Cross-sectional: (d3) If applicable, describe analytical methods
taking account of sampling strategy.
(e) Describe any sensitivity analyses.
- RE13 (a) 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. (b) Give reasons for non-participation at each stage. (c)
Consider use of a flow diagram.
- RE14 Give characteristics of (a1) study participants
(demographic, clinical, social) and information on (a2) exposures and
(a3) potential confounders. (b) Indicate number of participants with
missing data for each variable of interest.
Cohort: (c) Summarise follow-up time (eg, average and total amount)
- RE15 Numbers
Cohort: (a) Report numbers of outcome events or summary measures over
time.
Case-control: (b) Report numbers in each exposure category, or summary
measures of exposure.
Cross-sectional: (c) Report numbers of outcome events or summary
measures
- RE16 (a1) Give unadjusted estimates and, if applicable, (a2)
confounder-adjusted estimates and (a3) their precision (eg, 95%
confidence interval). (a4) 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.
- RE17 Other analyses. Report other analyses done—eg analyses
of subgroups and interactions, and sensitivity analyses
- DI18 Discussion Key results. Summarise key results with
reference to study objectives.
- DI19 Limitations. Discuss limitations of the study, taking
into account sources of potential bias or imprecision. Discuss both
direction and magnitude of any potential bias.
- DI20 Interpretation. Give a cautious overall interpretation
of results considering objectives, limitations, multiplicity of
analyses, results from similar studies, and other relevant evidence.
- DI21 Generalisability. Discuss the generalisability (external
validity) of the study results.
- DI22 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.
Supplementary table 1. Variables and rate of reporting where applicable
Items are labelled as XX#_y where XX represents the STROBE section
[TA (title and abstract), IN (introduction), ME (methods), RE
(results), DI (discussion)], where # represents the STROBE item
[1-22], and where y is the lowercase alphanumerical listing [(a),
(b), (c), …] indicating the sub-items defined in the section
above.