Cited by 120Meta-analysis and systematic reviewsClinical practice guidelines implementationPharmaceutical industry and healthcare

Accumulating Research: A Systematic Account of How Cumulative Meta-Analyses Would Have Provided Knowledge, Improved Health, Reduced Harm and Saved Resources

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Clarke, Mike, Brice, Anne, Chalmers, Iain·2014·PLoS ONE

Abstract

BACKGROUND: "Cumulative meta-analysis" describes a statistical procedure to calculate, retrospectively, summary estimates from the results of similar trials every time the results of a further trial in the series had become available. In the early 1990 s, comparisons of cumulative meta-analyses of treatments for myocardial infarction with advice promulgated through medical textbooks showed that research had continued long after robust estimates of treatment effects had accumulated, and that medical textbooks had overlooked strong, existing evidence from trials. Cumulative meta-analyses have subsequently been used to assess what could have been known had new studies been informed by systematic reviews of relevant existing evidence and how waste might have been reduced. METHODS AND FINDINGS: We used a systematic approach to identify and summarise the findings of cumulative meta-analyses of studies of the effects of clinical interventions, published from 1992 to 2012. Searches were done of PubMed, MEDLINE, EMBASE, the Cochrane Methodology Register and Science Citation Index. A total of 50 eligible reports were identified, including more than 1,500 cumulative meta-analyses. A variety of themes are illustrated with specific examples. The studies showed that initially positive results became null or negative in meta-analyses as more trials were done; that early null or negative results were over-turned; that stable results (beneficial, harmful and neutral) would have been seen had a meta-analysis been done before the new trial; and that additional trials had been much too small to resolve the remaining uncertainties. CONCLUSIONS: This large, unique collection of cumulative meta-analyses highlights how a review of the existing evidence might have helped researchers, practitioners, patients and funders make more informed decisions and choices about new trials over decades of research. This would have led to earlier uptake of effective interventions in practice, less exposure of trial participants to less effective treatments, and reduced waste resulting from unjustified research.

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Research works printed but not linked: 3

  1. [3]Rennie D, Chalmers I (2009) Exposing the dangers to patients of medical reviews and textbooks that ignore scientific principles. JLL Bulletin: Commentaries on the history of treatment evaluation (www.jameslindlibrary.org).
  2. [34]Deshpande G, Rao S, Patole S, Bulsara M (2010) Trial sequential analysis of updated meta-analysis of probiotics for preventing necrotising enterocolitis in preterm VLBW neonates: are the results conclusive? Journal of Paediatrics and Child Health, Conference: 14th Annual Congress of the Perinatal Society of Australia and New Zealand, PSANZ 2010 Wellington New Zealand. 46: 65.
  3. [53]Palmer S, Navaneethan S, Craig J, Johnson D, Tonelli M, et al (2010) Erythropoiesis-stimulating agents in people with chronic kidney disease: a cumulative meta-analysis. NDT Plus, Conference: 17th ERA-EDTA Congress - II DGfN Congress Munich Germany 3: iii80– iii81.

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Authors
Clarke, M., Brice, A., & Chalmers, I.
Affiliations
Queen's University Belfast (GB)
Corresponding author
Clarke, Mike
Venue
PLoS ONE
Published
2014-07-28
Volume
9
Issue
7
Pages
e102670
ISSN
1932-6203 (ISSN-L)
OpenAlex
W2087358018
Cited by
120
References
74
Citations by year
2026: 5 · 2025: 12 · 2024: 11 · 2023: 15 · 2022: 9 · 2021: 11 · 2020: 9 · 2019: 7 · 2018: 6 · 2017: 10 · 2016: 13 · 2015: 9 · 2014: 3
FWCI
11.42
Type
journal article
Language
en
Open access
Locations
  • PLoS ONE (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Research Portal (Queen's University Belfast) (submittedVersion, other-oa)
  • RePEc: Research Papers in Economics (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Clinical practice guidelines implementation
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmaceutical industry and healthcare
Keywords
cumulative meta-analysis, research waste, clinical trial design, treatment effect heterogeneity, negative results, research funding allocation, evidence-based decision making, myocardial infarction treatment, medical textbooks
MeSH terms
Health Status, Humans, Harm Reduction, Resource Allocation

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