Issues in the reporting of epidemiological studies: a survey of recent practice.
Open accessAbstract
Objectives To review current practice in the analysis and reporting of epidemiological research and to identify limitations. Design Examination of articles published in January 2001 that investigated associations between risk factors/exposure variables and disease events/measures in individuals. Setting Eligible English language journals including all major epidemiological journals, all major general medical journals, and the two leading journals in cardiovascular disease and cancer. Main outcome measure Each article was evaluated with a standard proforma. Results We found 73 articles in observational epidemiology; most were either cohort or case-control studies. Most studies looked at cancer and cardiovascular disease, even after we excluded specialty journals. Quantitative exposure variables predominated, which were mostly analysed as ordered categories but with little consistency or explanation regarding choice of categories. Sample selection, participant refusal, and data quality received insufficient attention in many articles. Statistical analyses commonly used odds ratios (38 articles) and hazard/rate ratios (23), with some inconsistent use of terminology. Confidence intervals were reported in most studies (68), though use of P values was less common (38). Few articles explained their choice of confounding variables; many performed subgroup analyses claiming an effect modifier, though interaction tests were rare. Several investigated multiple associations between exposure and outcome, increasing the likelihood of false positive claims. There was evidence of publication bias. Conclusions This survey raises concerns regarding inadequacies in the analysis and reporting of epidemiological publications in mainstream journals.
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Reporting of observational research is often not detailed and clear enough to assess the strengths and weaknesses of the investigation.
“Reporting of observational research is often not detailed and clear enough to assess the strengths and weaknesses of the investigation [ 4 , 5 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Another study found that among 67 articles in which statistical analyses were adjusted for confounders, it was mostly unclear how confounders were chosen.
“Another study found that among 67 articles in which statistical analyses were adjusted for confounders, it was mostly unclear how confounders were chosen [ 4 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
In a recent survey, two thirds of epidemiological publications studied quantitative exposure variables.
“In a recent survey, two thirds of epidemiological publications studied quantitative exposure variables [ 4 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
In 42 of 50 articles (84%) exposures were grouped into several ordered categories, but often without any stated rationale for the choices made.
“In 42 of 50 articles (84%) exposures were grouped into several ordered categories, but often without any stated rationale for the choices made.”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Subgroup analyses are nevertheless often done.
“Subgroup analyses are nevertheless often done [ 4 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Few epidemiological studies explain or report deliberations about sample size.
“Few epidemiological studies explain or report deliberations about sample size [ 4 , 5 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Fifteen articles used linear associations to model continuous exposure but only two reported checking for linearity.
“Fifteen articles used linear associations to model continuous exposure but only two reported checking for linearity.”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Many debate the use and value of analyses restricted to subgroups of the study population.
“many debate the use and value of analyses restricted to subgroups of the study population [ 4 , 104 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Incomplete or absent reporting of participation and non-participation in epidemiological studies was also documented in two other surveys of the literature.
“Incomplete or absent reporting of participation and non-participation in epidemiological studies was also documented in two other surveys of the literature [ 4 , 5 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Recent studies of the quality of reporting of epidemiological studies found that confidence intervals were reported in most articles.
“Recent studies of the quality of reporting of epidemiological studies found that confidence intervals were reported in most articles [ 4 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Few authors explained their choice of confounding variables.
“However, few authors explained their choice of confounding variables [ 4 , 5 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
The majority of articles with subgroup analyses claimed differences across groups but only eight articles reported a formal evaluation of interaction.
“The majority claimed differences across groups but only eight articles reported a formal evaluation of interaction (see item 12b) [ 4 ].”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
Pocock and colleagues found that 43 out of 73 articles reporting observational studies contained subgroup analyses.
“Pocock and colleagues found that 43 out of 73 articles reporting observational studies contained subgroup analyses.”
From Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration (2007) · cites this paper as [4]
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.
“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].”
From The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: Guidelines for Reporting Observational Studies (2007) · cites this paper as [6]
The reporting of observational research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability.
“The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability.”
From The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: Guidelines for reporting observational studies (2014) · cites this paper as [6]
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.
“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].”
From The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: Guidelines for reporting observational studies (2014) · cites this paper as [6]
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Bias in psychiatric case–control studies: Literature survey
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Untitled work
von Elm, E., Altman, D. G., Egger, M., Pocock, S. J., Gøtzsche, P. C., & Vandenbroucke, J. P. (2007) · PLoS Medicine
- Authors
- Pocock, S. J., Collier, T. J., Dandreo, K. J., de Stavola, B. L., Goldman, M. B., Kalish, L. A., Kasten, L. E., & McCormack, V. A.
- Affiliations
- London School of Hygiene & Tropical Medicine (GB)
- New England Research Institutes (US)
- Beth Israel Deaconess Medical Center (US)
- Boston Children's Hospital (US)
- Corresponding author
- Pocock, Stuart J
- Venue
- BMJ
- Publisher
- BMJ
- Published
- 2004-10-06
- Volume
- 329
- Issue
- 7471
- Pages
- 883
- ISSN
- 1756-1833 (ISSN-L)
- 0959-8138
- PMC
- PMC523109
- OpenAlex
- W2018466489
- Cited by
- 313
- References
- 58
- Citations by year
- 2026: 6 · 2025: 6 · 2024: 8 · 2023: 4 · 2022: 8 · 2021: 11 · 2020: 8 · 2019: 9 · 2018: 12 · 2017: 11 · 2016: 13 · 2015: 15 · 2014: 12 · 2013: 18 · 2012: 12
- FWCI
- 3.59
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- www.bmj.com/company/legal-information/terms-conditions/legal-information/tdm-licencepolicy (tdm)
- Locations
- BMJ (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- LSHTM Research Online (London School of Hygiene and Tropical Medicine) (acceptedVersion)
- UCL Discovery (University College London) (submittedVersion)
- HighWire Press Open Archive (submittedVersion)
- Topics
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
- Health Sciences › Health Professions › Health Information Management › Methodologies in Health Research and Practice
- Keywords
- reporting quality, epidemiological studies, observational studies, cohort studies, case-control study, odds ratio, hazard ratio, confidence intervals, confounding, effect modification, subgroup analysis, publication bias, sample selection, cardiovascular disease, cancer
- MeSH terms
- Environmental Exposure, Humans, Periodicals as Topic, Epidemiologic Research Design, Confounding Factors, Epidemiologic, Effect Modifier, Epidemiologic, Epidemiologic Studies
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