Evidence-based research

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Evidence-based research (EBR) is "the use of prior research in a systematic and transparent way to inform a new study so that it is answering questions that matter in a valid, efficient and accessible manner".[1] According to EBR, any new study should be informed by systematically examining existing evidence to determine the study's need, design, and methods.[2] In addition, results of a study should be placed in context by incorporating them in a systematic review of similar earlier studies.[2]


In healthcare, research waste may arise from questions irrelevant to clinicians and patients, inappropriate design and methods, inaccessible full publication, and biased and unusable reports.[3] To avoid unnecessary or poorly designed studies, it has been argued that "new research should not be done unless the questions it proposes to address cannot be answered satisfactorily with existing evidence".[3]

The CONSORT statement recommends that the authors of clinical trials report interpretation that is "consistent with results, balancing benefits and harms, and considering other relevant evidence".[4] Ideally, authors should conduct a formal systematic review to summarize the results in the context of existing evidence.[4] At the minimum, researchers should discuss an existing systematic review of similar trials when a formal systematic review is impractical.[4] Discussing the results in the context of existing evidence by including a systematic review may prevent unethical exposure of human subjects to risk of research in unnecessary subsequent trials[4][5] and identify remaining uncertainties to inform future research.[6][7]

Systematic use of existing evidence in research[edit]

Studies have shown that systematic reviews of existing research evidence are sub-optimally used in planning a new research or summarizing the results.[8] found that only 2 of 25 randomized clinical trials published in five major general medical journals (Annals of Internal Medicine, BMJ, JAMA, The Lancet, and The New England Journal of Medicine) during May 1997 discussed the results with an updated systematic review. Subsequent reports showed that there has been little progress since the initial study.[9][10][11][12]

These reports also showed that the majority of randomized clinical trials published in five major general medical journals did not present any systematic reviews of existing evidence to justify the research.[10][11][12]

Robinson et al.[13] analyzed 1523 clinical trials included in 227 meta-analyses and concluded that "less than one quarter of relevant prior studies" were cited. They also confirmed the earlier findings that clinical trial reports do not present systematic review to justify the research or summarize the results.[13]

Empirical evidence of research waste[edit]

Cumulative meta-analyses of studies evaluating the effectiveness of medical interventions have shown that many clinical trials could have been avoided if a systematic review of existing evidence was done prior to conducting a new trial.[14][15][16]

For example, Lau et al.[14] analyzed 33 clinical trials (involving 36974 patients) evaluating the effectiveness of intravenous streptokinase for acute myocardial infarction. Their cumulative meta-analysis demonstrated that 25 of 33 trials could have been avoided if a systematic review was conducted prior to conducting a new trial. In other words, randomizing 34542 patients was potentially unnecessary.

Cumulative meta-analyses of observational studies also showed that the association between risk factors and serious outcomes could have been established much earlier if a systematic review of existing studies had been conducted.[17][18]


Evidence-Based Research Network[edit]

In 2014, the Evidence-Based Research Network (EBRNetwork) was created at the Evidence-Based Research meeting in Bergen, Norway "to implement Evidence-Based Research (EBR) by engaging the funders, regulators, researchers, academic institutions, and journals".[19] The aim of EBRNetwork is "to reduce waste in research by promoting no new studies without prior systematic review of existing evidence and efficient production, updating and dissemination of systematic reviews".[20] The EBRNetwork proposed a flow chart for evidence-based research and evidence-based research statement that contain recommendations for all parties involved in health research.[2]

Funding agency[edit]

The National Institute for Health Research (NIHR) in the UK mandates that proposals for any primary research applying for funding are justified by a review of the evidence done systematically.[21][22] The Medical Research Council of the UK, Canadian Institutes of Health Research (CIHR), Deutsche Forschungsgemeinschaft (DFG: German Research Foundation), and De Nederlandse organisatie voor gezondheidsonderzoek en zorginnovatie (ZonMw) require providing a systematic review for clinical trials applying for funding.[21]


Authors submitting a manuscript of research to the Lancet family of journals are required to provide "Research in context panel that should include a description of all evidence considered before undertaking the study" and "a full description and discussion of the context with an option of including up-to-date systematic review".[23]

See also[edit]


  1. ^ Robinson, Karen A. (2009). Use of prior research in the justification and interpretation of clinical trials. The Johns Hopkins University. OCLC 658045127.[page needed]
  2. ^ a b c Lund, Hans; Brunnhuber, Klara; Juhl, Carsten; Robinson, Karen; Leenaars, Marlies; Dorch, Bertil F; Jamtvedt, Gro; Nortvedt, Monica W; Christensen, Robin; Chalmers, Iain (2016). "Towards evidence based research". BMJ. 355: i5440. doi:10.1136/bmj.i5440. hdl:2066/165826. PMID 27797786.
  3. ^ a b Chalmers, Iain; Glasziou, Paul (2009). "Avoidable waste in the production and reporting of research evidence". The Lancet. 374 (9683): 86–9. doi:10.1016/s0140-6736(09)60329-9. PMID 19525005.
  4. ^ a b c d Moher, David; Hopewell, Sally; Schulz, Kenneth F; Montori, Victor; Gøtzsche, Peter C; Devereaux, P.J; Elbourne, Diana; Egger, Matthias; Altman, Douglas G (2010). "CONSORT 2010 Explanation and Elaboration: Updated guidelines for reporting parallel group randomised trials". Journal of Clinical Epidemiology. 63 (8): e1–37. doi:10.1016/j.jclinepi.2010.03.004. PMID 20346624.
  5. ^ Clarke, Mike (2004). "Doing New Research? Don't Forget the Old". PLOS Medicine. 1 (2): e35. doi:10.1371/journal.pmed.0010035. PMC 529424. PMID 15578106.
  6. ^ Gotzsche, P. C; Gjorup, I; Bonnen, H; Brahe, N. E. B; Becker, U; Burcharth, F (1995). "Somatostatin v placebo in bleeding oesophageal varices: Randomised trial and meta-analysis". BMJ. 310 (6993): 1495–8. doi:10.1136/bmj.310.6993.1495. PMC 2549875. PMID 7787594.
  7. ^ Sadler, L. C; Davison, T; McCowan, L. M. E (2000). "A randomised controlled trial and meta-analysis of active management of labour". BJOG: An International Journal of Obstetrics and Gynaecology. 107 (7): 909–15. doi:10.1111/j.1471-0528.2000.tb11091.x. PMID 10901564.
  8. ^ Clarke, Michael; Chalmers, Iain (1998). "Discussion Sections in Reports of Controlled Trials Published in General Medical Journals". JAMA. 280 (3): 280–2. doi:10.1001/jama.280.3.280. PMID 9676682.
  9. ^ Clarke, Mike; Alderson, P; Chalmers, I (2002). "Discussion Sections in Reports of Controlled Trials Published in General Medical Journals". JAMA. 287 (21): 2799–801. doi:10.1001/jama.287.21.2799. PMID 12038916.
  10. ^ a b Clarke, M; Hopewell, S; Chalmers, I (2007). "Reports of clinical trials should begin and end with up-to-date systematic reviews of other relevant evidence: A status report". Journal of the Royal Society of Medicine. 100 (4): 187–190. doi:10.1258/jrsm.100.4.187. PMC 1847744. PMID 17404342.
  11. ^ a b Clarke, Mike; Hopewell, Sally; Chalmers, Iain (2010). "Clinical trials should begin and end with systematic reviews of relevant evidence: 12 years and waiting". The Lancet. 376 (9734): 20–1. doi:10.1016/s0140-6736(10)61045-8. PMID 20609983.
  12. ^ a b Clarke, Michael; Hopewell, Sally (2013). "Many reports of randomised trials still don't begin or end with a systematic review of the relevant evidence". Journal of the Bahrain Medical Society. 24 (3): 145–148.
  13. ^ a b Robinson, Karen A; Goodman, Steven N (2011). "A Systematic Examination of the Citation of Prior Research in Reports of Randomized, Controlled Trials". Annals of Internal Medicine. 154 (1): 50–5. doi:10.7326/0003-4819-154-1-201101040-00007. PMID 21200038.
  14. ^ a b Lau, Joseph; Antman, Elliott M; Jimenez-Silva, Jeanette; Kupelnick, Bruce; Mosteller, Frederick; Chalmers, Thomas C (1992). "Cumulative Meta-Analysis of Therapeutic Trials for Myocardial Infarction". New England Journal of Medicine. 327 (4): 248–54. doi:10.1056/NEJM199207233270406. PMID 1614465.
  15. ^ Fergusson, Dean; Glass, Kathleen Cranley; Hutton, Brian; Shapiro, Stan (2016). "Randomized controlled trials of aprotinin in cardiac surgery: Could clinical equipoise have stopped the bleeding?". Clinical Trials: Journal of the Society for Clinical Trials. 2 (3): 218–29, discussion 229–32. doi:10.1191/1740774505cn085oa. PMID 16279145.
  16. ^ Clarke, Mike; Brice, Anne; Chalmers, Iain (2014). "Accumulating Research: A Systematic Account of How Cumulative Meta-Analyses Would Have Provided Knowledge, Improved Health, Reduced Harm and Saved Resources". PLOS ONE. 9 (7): e102670. Bibcode:2014PLoSO...9j2670C. doi:10.1371/journal.pone.0102670. PMC 4113310. PMID 25068257.
  17. ^ Gilbert, Ruth; Salanti, Georgia; Harden, Melissa; See, Sarah (2005). "Infant sleeping position and the sudden infant death syndrome: Systematic review of observational studies and historical review of recommendations from 1940 to 2002". International Journal of Epidemiology. 34 (4): 874–87. doi:10.1093/ije/dyi088. PMID 15843394.
  18. ^ Taylor, R; Najafi, F; Dobson, A (2007). "Meta-analysis of studies of passive smoking and lung cancer: Effects of study type and continent". International Journal of Epidemiology. 36 (5): 1048–59. doi:10.1093/ije/dym158. PMID 17690135.
  19. ^ Chalmers, Iain; Nylenna, Magne (2014). "A new network to promote evidence-based research". The Lancet. 384 (9958): 1903–4. doi:10.1016/S0140-6736(14)62252-2. PMID 25435440.
  20. ^ "Hans Lund: A brief introduction to the concept of evidence-based research". May 7, 2015.
  21. ^ a b Nasser, Mona; Clarke, Mike; Chalmers, Iain; Brurberg, Kjetil Gundro; Nykvist, Hanna; Lund, Hans; Glasziou, Paul (2017). "What are funders doing to minimise waste in research?". The Lancet. 389 (10073): 1006–1007. doi:10.1016/S0140-6736(17)30657-8. PMID 28290987.
  22. ^ Bhurke, Sheetal; Cook, Andrew; Tallant, Anna; Young, Amanda; Williams, Elaine; Raftery, James (2015). "Using systematic reviews to inform NIHR HTA trial planning and design: A retrospective cohort". BMC Medical Research Methodology. 15: 108. doi:10.1186/s12874-015-0102-2. PMC 4696153. PMID 26715462.
  23. ^ "Information for Authors". The Lancet. April 2018.