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Davidson M, Korfitsen CB, Riveros C, Chaimani A, Boutron I. Post-publication peer review and the identification of methodological and reporting issues in COVID-19 trials: a qualitative study. BMJ Evid Based Med 2025:bmjebm-2024-113068. [PMID: 39978958 DOI: 10.1136/bmjebm-2024-113068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/07/2025] [Indexed: 02/22/2025]
Abstract
OBJECTIVES We aimed to determine to what extent systematic reviewers and post-preprint and post-publication peer review identified methodological and reporting issues in COVID-19 trials that could be easily resolved by the authors. DESIGN Qualitative study. DATA SOURCES COVID-NMA living systematic review (covid-nma.com), PubPeer, medRxiv, Research Square, SSRN. METHODS We considered randomised controlled trials (RCTs) in COVID-NMA that evaluated pharmacological treatments for COVID-19 and retrieved systematic reviewers' assessments of the risk of bias and outcome reporting bias. We also searched for commentary data on PubPeer and preprint servers up to 6 November 2023. We employed qualitative content analysis to develop themes and domains of methodological and reporting issues identified by commenters. RESULTS We identified 500 eligible RCTs. Systematic reviewers identified methodological and reporting issues in 446 (89%) RCTs. In 391 (78%) RCTs, the issues could be easily resolved by the trial authors; issues included incomplete reporting (49%), selection of the reported results (52%) and no access to the pre-specified plan (25%). Alternatively, 74 (15%) RCTs had received at least one comment on PubPeer or preprint servers, totalling 348 comments. In 46 (9%) RCTs, the issues identified by post-preprint and post-publication peer review comments could be easily resolved by the trial authors; the issues were related to incomplete reporting (6%), errors (5%), statistical analysis (3%), inconsistent reporting of methods and analyses (2%), spin (2%), selection of the reported results (1%) and no access to the raw data/pre-specified plan (1%). CONCLUSIONS Without changing their process, systematic reviewers identified issues in most RCTs that could be easily resolved by the trial authors; however, the lack of an established author feedback mechanism represents a wasted opportunity for facilitating improvement and enhancing the overall manuscript quality. On the other hand, despite the existing feedback loop to authors present in post-publication peer review, it demonstrated limited effectiveness in identifying methodological and reporting issues.
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Affiliation(s)
- Mauricia Davidson
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Centre for Research in Epidemiology and Statistics (CRESS), Paris, Île-de-France, France
| | - Christoffer Bruun Korfitsen
- Open Patient Data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark
- Cochrane Denmark & Centre for Evidence-Based Medicine Odense (CEBMO), Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Carolina Riveros
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Centre for Research in Epidemiology and Statistics (CRESS), Paris, Île-de-France, France
- Cochrane Centre France, Paris, Île-de-France, France
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, Paris, Île-de-France, France
| | - Anna Chaimani
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Centre for Research in Epidemiology and Statistics (CRESS), Paris, Île-de-France, France
- Cochrane Centre France, Paris, Île-de-France, France
| | - Isabelle Boutron
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Centre for Research in Epidemiology and Statistics (CRESS), Paris, Île-de-France, France
- Cochrane Centre France, Paris, Île-de-France, France
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, Paris, Île-de-France, France
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Wilson P, Huser V. Evaluating the discoverability of supporting research materials in ClinicalTrials.gov for US federally funded COVID-19 clinical studies. J Med Libr Assoc 2024; 112:250-260. [PMID: 39308913 PMCID: PMC11412123 DOI: 10.5195/jmla.2024.1799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/25/2024] Open
Abstract
Objective The objective of this study was to evaluate the discoverability of supporting research materials, including supporting documents, individual participant data (IPD), and associated publications, in US federally funded COVID-19 clinical study records in ClinicalTrials.gov (CTG). Methods Study registration records were evaluated for (1) links to supporting documents, including protocols, informed consent forms, and statistical analysis plans; (2) information on how unaffiliated researchers may access IPD and, when applicable, the linking of the IPD record back to the CTG record; and (3) links to associated publications and, when applicable, the linking of the publication record back to the CTG record. Results 206 CTG study records were included in the analysis. Few records shared supporting documents, with only 4% of records sharing all 3 document types. 27% of records indicated they intended to share IPD, with 45% of these providing sufficient information to request access to the IPD. Only 1 dataset record was located, which linked back to its corresponding CTG record. The majority of CTG records did not have links to publications (61%), and only 21% linked out to at least 1 results publication. All publication records linked back to their corresponding CTG records. Conclusion With only 4% of records sharing all supporting document types, 12% sufficient information to access IPD, and 21% results publications, improvements can be made to the discoverability of research materials in federally funded, COVID-19 CTG records. Sharing these materials on CTG can increase their discoverability, therefore increasing the validity, transparency, and reusability of clinical research.
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Affiliation(s)
- Paije Wilson
- , Health Sciences Librarian, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI
| | - Vojtech Huser
- , Adjunct Professor of Clinical Research and Leadership, The George Washington University School of Medicine & Health Sciences, Washington, D.C
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Visram AS, Jackson IR, Guest H, Plack CJ, Brij S, Chaudhuri N, Munro KJ. Pre-registered controlled comparison of auditory function reveals no difference between hospitalised adults with and without COVID-19. Int J Audiol 2024; 63:300-312. [PMID: 37363933 DOI: 10.1080/14992027.2023.2213841] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 05/03/2023] [Accepted: 05/08/2023] [Indexed: 06/28/2023]
Abstract
OBJECTIVE Several viruses are known to have a negative impact on hearing health. The global prevalence of COVID-19 means that it is crucial to understand whether and how SARS-CoV2 affects hearing. Evidence to date is mixed, with studies frequently exhibiting limitations in the methodological approaches used or the populations sampled, leading to a substantial risk of bias. This study addressed many of these limitations. DESIGN A comprehensive battery of measures was administered, including lab-based behavioural and physiological measures, as well as self-report instruments. Performance was thoroughly assessed across the auditory system, including measures of cochlear function, neural function and auditory perception. Hypotheses and analyses were pre-registered. STUDY SAMPLES Participants who were hospitalised as a result of COVID-19 (n = 57) were compared with a well-matched control group (n = 40) who had also been hospitalised but had never had COVID-19. RESULTS We find no evidence to support the hypothesis that COVID-19 is associated with deficits in auditory function on any auditory test measure. Of all the confirmatory analyses, only the self-report measure of hearing decline indicated any difference between groups. CONCLUSION Results do not support the hypothesis that COVID-19 infection has a significant long-term impact on the auditory system.
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Affiliation(s)
- A S Visram
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
| | - I R Jackson
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
| | - H Guest
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
| | - C J Plack
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
- Department of Psychology, Lancaster University, Lancaster, UK
| | - S Brij
- Department of Respiratory Medicine, Manchester Royal Infirmary, Manchester University NHS Foundation Trust, Manchester, UK
| | - N Chaudhuri
- Magee Medical School, The University of Ulster, Londonderry, UK
| | - K J Munro
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
- University of Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
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Davidson M, Evrenoglou T, Graña C, Chaimani A, Boutron I. Comparison of effect estimates between preprints and peer-reviewed journal articles of COVID-19 trials. BMC Med Res Methodol 2024; 24:9. [PMID: 38212714 PMCID: PMC10782611 DOI: 10.1186/s12874-023-02136-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 12/22/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND Preprints are increasingly used to disseminate research results, providing multiple sources of information for the same study. We assessed the consistency in effect estimates between preprint and subsequent journal article of COVID-19 randomized controlled trials. METHODS The study utilized data from the COVID-NMA living systematic review of pharmacological treatments for COVID-19 (covid-nma.com) up to July 20, 2022. We identified randomized controlled trials (RCTs) evaluating pharmacological treatments vs. standard of care/placebo for patients with COVID-19 that were originally posted as preprints and subsequently published as journal articles. Trials that did not report the same analysis in both documents were excluded. Data were extracted independently by pairs of researchers with consensus to resolve disagreements. Effect estimates extracted from the first preprint were compared to effect estimates from the journal article. RESULTS The search identified 135 RCTs originally posted as a preprint and subsequently published as a journal article. We excluded 26 RCTs that did not meet the eligibility criteria, of which 13 RCTs reported an interim analysis in the preprint and a final analysis in the journal article. Overall, 109 preprint-article RCTs were included in the analysis. The median (interquartile range) delay between preprint and journal article was 121 (73-187) days, the median sample size was 150 (71-464) participants, 76% of RCTs had been prospectively registered, 60% received industry or mixed funding, 72% were multicentric trials. The overall risk of bias was rated as 'some concern' for 80% of RCTs. We found that 81 preprint-article pairs of RCTs were consistent for all outcomes reported. There were nine RCTs with at least one outcome with a discrepancy in the number of participants with outcome events or the number of participants analyzed, which yielded a minor change in the estimate of the effect. Furthermore, six RCTs had at least one outcome missing in the journal article and 14 RCTs had at least one outcome added in the journal article compared to the preprint. There was a change in the direction of effect in one RCT. No changes in statistical significance or conclusions were found. CONCLUSIONS Effect estimates were generally consistent between COVID-19 preprints and subsequent journal articles. The main results and interpretation did not change in any trial. Nevertheless, some outcomes were added and deleted in some journal articles.
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Affiliation(s)
- Mauricia Davidson
- Center for Research in Epidemiology and Statistics (CRESS-U1153), Université Paris Cité and Université Sorbonne Paris Nord, INRAE, Inserm, Hôpital Hôtel-Dieu, 1 Place du Parvis Notre-Dame, Paris, F-75004, France.
| | - Theodoros Evrenoglou
- Center for Research in Epidemiology and Statistics (CRESS-U1153), Université Paris Cité and Université Sorbonne Paris Nord, INRAE, Inserm, Hôpital Hôtel-Dieu, 1 Place du Parvis Notre-Dame, Paris, F-75004, France
| | - Carolina Graña
- Center for Research in Epidemiology and Statistics (CRESS-U1153), Université Paris Cité and Université Sorbonne Paris Nord, INRAE, Inserm, Hôpital Hôtel-Dieu, 1 Place du Parvis Notre-Dame, Paris, F-75004, France
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, Paris, F-75004, France
- Cochrane France, Paris, France
| | - Anna Chaimani
- Center for Research in Epidemiology and Statistics (CRESS-U1153), Université Paris Cité and Université Sorbonne Paris Nord, INRAE, Inserm, Hôpital Hôtel-Dieu, 1 Place du Parvis Notre-Dame, Paris, F-75004, France
- Cochrane France, Paris, France
| | - Isabelle Boutron
- Center for Research in Epidemiology and Statistics (CRESS-U1153), Université Paris Cité and Université Sorbonne Paris Nord, INRAE, Inserm, Hôpital Hôtel-Dieu, 1 Place du Parvis Notre-Dame, Paris, F-75004, France
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, Paris, F-75004, France
- Cochrane France, Paris, France
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Catalá-López F, Ridao M, Tejedor-Romero L, Caulley L, Hutton B, Husereau D, Alonso-Arroyo A, Bernal-Delgado E, Drummond MF, Moher D. Transparency, openness, and reproducible research practices are frequently underused in health economic evaluations. J Clin Epidemiol 2024; 165:111208. [PMID: 37939742 DOI: 10.1016/j.jclinepi.2023.10.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/15/2023] [Accepted: 10/31/2023] [Indexed: 11/10/2023]
Abstract
OBJECTIVES To investigate the extent to which articles of economic evaluations of healthcare interventions indexed in MEDLINE incorporate research practices that promote transparency, openness, and reproducibility. STUDY DESIGN AND SETTING We evaluated a random sample of health economic evaluations indexed in MEDLINE during 2019. We included articles written in English reporting an incremental cost-effectiveness ratio in terms of costs per life years gained, quality-adjusted life years, and/or disability-adjusted life years. Reproducible research practices, openness, and transparency in each article were extracted in duplicate. We explored whether reproducible research practices were associated with self-report use of a guideline. RESULTS We included 200 studies published in 147 journals. Almost half were published as open access articles (n = 93; 47%). Most studies (n = 150; 75%) were model-based economic evaluations. In 109 (55%) studies, authors self-reported use a guideline (e.g., for study conduct or reporting). Few studies (n = 31; 16%) reported working from a protocol. In 112 (56%) studies, authors reported the data needed to recreate the incremental cost-effectiveness ratio for the base case analysis. This percentage was higher in studies using a guideline than studies not using a guideline (72/109 [66%] with guideline vs. 40/91 [44%] without guideline; risk ratio 1.50, 95% confidence interval 1.15-1.97). Only 10 (5%) studies mentioned access to raw data and analytic code for reanalyses. CONCLUSION Transparency, openness, and reproducible research practices are frequently underused in health economic evaluations. This study provides baseline data to compare future progress in the field.
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Affiliation(s)
- Ferrán Catalá-López
- Department of Health Planning and Economics, National School of Public Health, Institute of Health Carlos III, Madrid, Spain; Department of Medicine, University of Valencia/INCLIVA Health Research Institute and CIBERSAM, Valencia, Spain; Clinical Epidemiology Program, Ottawa Hospital Research Institute (OHRI), Ottawa, Ontario, Canada.
| | - Manuel Ridao
- Institute for Health Research in Aragon (IISA), Zaragoza, Spain; Data Science for Health Services and Policy Research, Aragon Health Sciences Institute (IACS), Zaragoza, Spain; Research Network on Chronicity, Primary Care, and Health Promotion (RICAPPS), Institute of Health Carlos III, Madrid, Spain
| | - Laura Tejedor-Romero
- Department of Health Planning and Economics, National School of Public Health, Institute of Health Carlos III, Madrid, Spain; Preventive Medicine Unit, La Princesa University Teaching Hospital, Madrid, Spain; Division of Pharmacoepidemiology and Pharmacovigilance, Spanish Medicines and Healthcare Products Agency (AEMPS), Madrid, Spain
| | - Lisa Caulley
- Clinical Epidemiology Program, Ottawa Hospital Research Institute (OHRI), Ottawa, Ontario, Canada; Otolaryngology-Head and Neck Surgery Department, Ottawa Hospital, Ottawa, Ontario, Canada; Department of Clinical Medicine and Otolaryngology-Head and Neck Surgery, Aarhus University, Aarhus, Denmark
| | - Brian Hutton
- Clinical Epidemiology Program, Ottawa Hospital Research Institute (OHRI), Ottawa, Ontario, Canada; School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Don Husereau
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Institute of Health Economics, Edmonton, Alberta, Canada
| | - Adolfo Alonso-Arroyo
- Department of History of Science and Documentation, University of Valencia, Valencia, Spain; Information and Social and Health Research (UISYS) Joint Research Unit, Spanish National Research Council (CSIC), University of Valencia, Valencia, Spain
| | - Enrique Bernal-Delgado
- Data Science for Health Services and Policy Research, Aragon Health Sciences Institute (IACS), Zaragoza, Spain; Research Network on Chronicity, Primary Care, and Health Promotion (RICAPPS), Institute of Health Carlos III, Madrid, Spain
| | | | - David Moher
- Clinical Epidemiology Program, Ottawa Hospital Research Institute (OHRI), Ottawa, Ontario, Canada; School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Salholz-Hillel M, Pugh-Jones M, Hildebrand N, Schult TA, Schwietering J, Grabitz P, Carlisle BG, Goldacre B, Strech D, DeVito NJ. Dissemination of Registered COVID-19 Clinical Trials (DIRECCT): a cross-sectional study. BMC Med 2023; 21:475. [PMID: 38031096 PMCID: PMC10687901 DOI: 10.1186/s12916-023-03161-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 11/07/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND The results of clinical trials should be completely and rapidly reported during public health emergencies such as COVID-19. This study aimed to examine when, and where, the results of COVID-19 clinical trials were disseminated throughout the first 18 months of the pandemic. METHODS Clinical trials for COVID-19 treatment or prevention were identified from the WHO ICTRP database. All interventional trials with a registered completion date ≤ 30 June 2021 were included. Trial results, published as preprints, journal articles, or registry results, were located using automated and manual techniques across PubMed, Google Scholar, Google, EuropePMC, CORD-19, the Cochrane COVID-19 Study Register, and clinical trial registries. Our main analysis reports the rate of dissemination overall and per route, and the time from registered completion to results using Kaplan-Meier methods, with additional subgroup and sensitivity analyses reported. RESULTS Overall, 1643 trials with completion dates ranging from 46 to 561 days prior to the start of results searches were included. The cumulative probability of reporting was 12.5% at 3 months from completion, 21.6% at 6 months, and 32.8% at 12 months. Trial results were most commonly disseminated in journals (n = 278 trials, 69.2%); preprints were available for 194 trials (48.3%), 86 (44.3%) of which converted to a full journal article. Trials completed earlier in the pandemic were reported more rapidly than those later in the pandemic, and those involving ivermectin were more rapidly reported than other common interventions. Results were robust to various sensitivity analyses except when considering only trials in a "completed" status on the registry, which substantially increased reporting rates. Poor trial registry data on completion status and dates limits the precision of estimates. CONCLUSIONS COVID-19 trials saw marginal increases in reporting rates compared to standard practice; most registered trials failed to meet even the 12-month non-pandemic standard. Preprints were common, complementing journal publication; however, registries were underutilized for rapid reporting. Maintaining registry data enables accurate representation of clinical research; failing to do so undermines these registries' use for public accountability and analysis. Addressing rapid reporting and registry data quality must be emphasized at global, national, and institutional levels.
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Affiliation(s)
- Maia Salholz-Hillel
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Molly Pugh-Jones
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Nicole Hildebrand
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Tjada A Schult
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes Schwietering
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Grabitz
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Benjamin Gregory Carlisle
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Ben Goldacre
- Bennett Institute for Applied Data Science, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Daniel Strech
- QUEST Center for Responsible Research, Berlin Institute of Health (BIH), Charite Universitätsmedizin Berlin, Berlin, Germany
| | - Nicholas J DeVito
- Bennett Institute for Applied Data Science, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
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Dal-Ré R. COVID-19 research waste: An analysis on terminated clinical trials on medicines on ClinicalTrials.gov. Eur J Intern Med 2023; 117:126-128. [PMID: 37507265 DOI: 10.1016/j.ejim.2023.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Affiliation(s)
- Rafael Dal-Ré
- Epidemiology Unit, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid, Madrid, Spain.
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Davidson M, Evrenoglou T, Graña C, Chaimani A, Boutron I. No evidence of important difference in summary treatment effects between COVID-19 preprints and peer-reviewed publications: a meta-epidemiological study. J Clin Epidemiol 2023; 162:90-97. [PMID: 37634703 DOI: 10.1016/j.jclinepi.2023.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/02/2023] [Accepted: 08/21/2023] [Indexed: 08/29/2023]
Abstract
OBJECTIVES Preprints became a major source of research communication during the COVID-19 pandemic. We aimed to evaluate whether summary treatment effect estimates differ between preprint and peer-reviewed journal trials. STUDY DESIGN AND SETTING A meta-epidemiological study. Data were derived from the COVID-NMA living systematic review (covid-nma.com) up to July 20, 2022. We identified all meta-analyses evaluating pharmacological treatments vs. standard of care or placebo for patients with COVID-19 that included at least one preprint and one peer-reviewed journal article. Difference in effect estimates between preprint and peer-reviewed journal trials were estimated by the ratio of odds ratio (ROR); ROR <1 indicated larger effects in preprint trials. RESULTS Thirty-seven meta-analyses including 114 trials (44 preprints and 70 peer-reviewed publications) were selected. The median number of randomized controlled trials (RCTs) per meta-analysis was 2 (interquartile range [IQR], 2-4; maximum, 11), median sample size of RCTs was 199 (IQR, 99-478). Overall, there was no statistically significant difference in summary effect estimates between preprint and peer-reviewed journal trials (ROR, 0.88; 95% CI, 0.71-1.09; I2 = 17.8%; τ2 = 0.06). CONCLUSION We did not find an important difference between summary treatment effects of preprints and summary treatment effects of peer-reviewed publications. Systematic reviewers and guideline developers should assess preprint inclusion individually, accounting for risk of bias and completeness of reporting.
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Affiliation(s)
- Mauricia Davidson
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris, France.
| | - Theodoros Evrenoglou
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris, France
| | - Carolina Graña
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris, France; Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France; Cochrane France, Paris, France
| | - Anna Chaimani
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris, France; Cochrane France, Paris, France
| | - Isabelle Boutron
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris, France; Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France; Cochrane France, Paris, France
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