TY - JOUR
T1 - Consistency of causal claims in observational studies: A review of papers published in a general medical journal
AU - Olarte Parra, Camila
AU - Bertizzolo, Lorenzo
AU - Schroter, Sara
AU - Dechartres, Agnès
AU - Goetghebeur, Els
N1 - Funding Information: Funding This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 676207. Publisher Copyright: © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.
PY - 2021/5/20
Y1 - 2021/5/20
N2 - Objective To evaluate the consistency of causal statements in observational studies published in The BMJ. Design Review of observational studies published in a general medical journal. Data source Cohort and other longitudinal studies describing an exposure-outcome relationship published in The BMJ in 2018. We also had access to the submitted papers and reviewer reports. Main outcome measures Proportion of published research papers with 'inconsistent' use of causal language. Papers where language was consistently causal or non-causal were classified as 'consistently causal' or 'consistently not causal', respectively. For the 'inconsistent' papers, we then compared the published and submitted version. Results Of 151 published research papers, 60 described eligible studies. Of these 60, we classified the causal language used as 'consistently causal' (48%), 'inconsistent' (20%) and 'consistently not causal'(32%). Eleven out of 12 (92%) of the 'inconsistent' papers were already inconsistent on submission. The inconsistencies found in both submitted and published versions were mainly due to mismatches between objectives and conclusions. One section might be carefully phrased in terms of association while the other presented causal language. When identifying only an association, some authors jumped to recommending acting on the findings as if motivated by the evidence presented. Conclusion Further guidance is necessary for authors on what constitutes a causal statement and how to justify or discuss assumptions involved. Based on screening these papers, we provide a list of expressions beyond the obvious 'cause' word which may inspire a useful more comprehensive compendium on causal language.
AB - Objective To evaluate the consistency of causal statements in observational studies published in The BMJ. Design Review of observational studies published in a general medical journal. Data source Cohort and other longitudinal studies describing an exposure-outcome relationship published in The BMJ in 2018. We also had access to the submitted papers and reviewer reports. Main outcome measures Proportion of published research papers with 'inconsistent' use of causal language. Papers where language was consistently causal or non-causal were classified as 'consistently causal' or 'consistently not causal', respectively. For the 'inconsistent' papers, we then compared the published and submitted version. Results Of 151 published research papers, 60 described eligible studies. Of these 60, we classified the causal language used as 'consistently causal' (48%), 'inconsistent' (20%) and 'consistently not causal'(32%). Eleven out of 12 (92%) of the 'inconsistent' papers were already inconsistent on submission. The inconsistencies found in both submitted and published versions were mainly due to mismatches between objectives and conclusions. One section might be carefully phrased in terms of association while the other presented causal language. When identifying only an association, some authors jumped to recommending acting on the findings as if motivated by the evidence presented. Conclusion Further guidance is necessary for authors on what constitutes a causal statement and how to justify or discuss assumptions involved. Based on screening these papers, we provide a list of expressions beyond the obvious 'cause' word which may inspire a useful more comprehensive compendium on causal language.
KW - education & training (see medical education & training)
KW - epidemiology
KW - statistics & research methods
UR - http://www.scopus.com/inward/record.url?scp=85106570397&partnerID=8YFLogxK
U2 - https://doi.org/10.1136/bmjopen-2020-043339
DO - https://doi.org/10.1136/bmjopen-2020-043339
M3 - Review article
C2 - 34016660
SN - 2044-6055
VL - 11
JO - BMJ Open
JF - BMJ Open
IS - 5
M1 - e043339
ER -