Publication bias
Publication bias is defined as "the influence of study results on the chances of publication [in academic journals] and the tendency of investigators, reviewers, and editors to submit or accept manuscripts for publication based on the direction or strength of the study findings. Publication bias has an impact on the interpretation of clinical trials and meta-analyses. Bias can be minimized by insistence by editors on high-quality research, thorough literature reviews, acknowledgment of conflicts of interest, modification of peer review practices, etc."[1] Publication bias has been documented to occur[2].
Whether a treatment or medical intervention is effective or not may be judged either by the experience of the practising physician, or by what has been published by others. The publications with greatest authority are generally those in the peer-reviewed scientific journals, and particularly those journals with the highest standards of editorial scrutiny. However, it is not simple to get a study published in any peer-reviewed journal, least of all in the best journals. Accordingly, many studies go unreported. It is often thought to be difficult to publish small studies, the outcome of which conflicts with the reported outcomes of larger previously published studies, or to publish studies from which no clear conclusion can be drawn. In part, this reflects the wish of the best journals to publish influential papers, and in part it reflects authors choosing not to publish studies that are thought to be uninteresting. Such publication bias can be difficult to recognise, but its effects tend to encourage publication of studies that support an already formed conclusion, while discouraging publication of contradictory or equivocal findings.[2][3]
Publication bias may be due to authors not submitting negative studies for publication.[3] This may especially be true of studies authored by industries with conflicts of interest.[4][5]
Publication bias, or bias in interpretation of studies, may be more common in certain areas of study and maybe also be associated with the language the study in published in. In the field of complementary and alternative medicine (CAM), publication bias may be more likely to occur in studies published in languages of than English.[6] This may be due to typical CAM studies being smaller than trials of conventional medicine[6]. According to two European analyses, both including German authors and one from the German Cochrane Center, this bias may be especially prevelent in German publications.[7][8]
An example of probable publication bias is in the studies of glucosamine and chondroitin for treatment of osteoarthritis. In an initial meta-analysis, the authors noted evidence of publication bias during examination of the results.[9] A subsequent large randomized controlled trial[10] and meta-analyses including the large trial were negative[11][12]. Another example is the selective publication of randomized controlled trials of antidepressant.[13]
Meta-analysis
Publication bias is a major threat to the validity of meta-analysis. Publication bias against negative studies may threaten the validity of meta-analyses that are positive and all the studies included within the meta-analysis are small.[14][15]
In performing a meta-analyses, a file drawer[16] or a funnel plot analysis[15][17] may help detect underlying publication bias among the studies in the meta-analysis.
Publication bias has also occurred in the publication of randomized controlled trials of antidepressants.[13]
Drug approval process
Publication bias occurs in the data submitted to the United States Food and Drug Administration[18][19] and to the Swedish drug regulatory authority[4]by drug companies.
References
- ↑ National Library of Medicine. Publication bias. Retrieved on 2007-12-17.
- ↑ 2.0 2.1 Dickersin K, Min YI, Meinert CL (1992). "Factors influencing publication of research results. Follow-up of applications submitted to two institutional review boards". JAMA 267 (3): 374–8. PMID 1727960. [e]
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<ref>tag; name "pmid1727960" defined multiple times with different content - ↑ 3.0 3.1 Krzyzanowska MK et al. (2003). "Factors associated with failure to publish large randomized trials presented at an oncology meeting". JAMA 290: 495–501. DOI:10.1001/jama.290.4.495. PMID 12876092. Research Blogging.
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<ref>tag; name "pmid12876092" defined multiple times with different content - ↑ 4.0 4.1 Melander H, Ahlqvist-Rastad J, Meijer G, Beermann B (2003). "Evidence b(i)ased medicine--selective reporting from studies sponsored by pharmaceutical industry: review of studies in new drug applications". BMJ 326 (7400): 1171–3. DOI:10.1136/bmj.326.7400.1171. PMID 12775615. Research Blogging.
- ↑ Lexchin J et al. (2003). "Pharmaceutical industry sponsorship and research outcome and quality: systematic review". BMJ 326: 1167–70. DOI:10.1136/bmj.326.7400.1167. PMID 12775614. Research Blogging.
- ↑ 6.0 6.1 Pham B, Klassen TP, Lawson ML, Moher D (2005). "Language of publication restrictions in systematic reviews gave different results depending on whether the intervention was conventional or complementary". J Clin Epidemiol 58 (8): 769–76. PMID 16086467. [e]
- ↑ Galandi D, Schwarzer G, Antes G (2006). "The demise of the randomised controlled trial: bibliometric study of the German-language health care literature, 1948 to 2004". BMC Med Res Methodol 6: 30. DOI:10.1186/1471-2288-6-30. PMID 16824217. Research Blogging.
- ↑ Lancet. 1997. Language bias in randomised controlled trials published in English and German. http://pubmed.gov/16086467
- ↑ McAlindon TE, LaValley MP, Gulin JP, Felson DT (2000). "Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis". JAMA 283 (11): 1469–75. PMID 10732937. [e]
- ↑ Clegg DO, Reda DJ, Harris CL, et al (2006). "Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis". N. Engl. J. Med. 354 (8): 795–808. DOI:10.1056/NEJMoa052771. PMID 16495392. Research Blogging.
- ↑ Vlad SC, LaValley MP, McAlindon TE, Felson DT (2007). "Glucosamine for pain in osteoarthritis: why do trial results differ?". Arthritis Rheum. 56 (7): 2267–77. DOI:10.1002/art.22728. PMID 17599746. Research Blogging.
- ↑ Reichenbach S, Sterchi R, Scherer M, et al (2007). "Meta-analysis: chondroitin for osteoarthritis of the knee or hip". Ann. Intern. Med. 146 (8): 580–90. PMID 17438317. [e]
- ↑ 13.0 13.1 Turner EH, Matthews AM, Linardatos E, Tell RA, Rosenthal R (2008). "Selective publication of antidepressant trials and its influence on apparent efficacy". N. Engl. J. Med. 358 (3): 252–60. DOI:10.1056/NEJMsa065779. PMID 18199864. Research Blogging.
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<ref>tag; name "pmid18199864" defined multiple times with different content - ↑ Sutton AJ, Duval SJ, Tweedie RL, Abrams KR, Jones DR (2000). "Empirical assessment of effect of publication bias on meta-analyses". BMJ 320 (7249): 1574–7. PMID 10845965. [e]
- ↑ 15.0 15.1 Egger M, Davey Smith G, Schneider M, Minder C (1997). "Bias in meta-analysis detected by a simple, graphical test". BMJ 315 (7109): 629–34. PMID 9310563. [e]
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<ref>tag; name "pmid9310563" defined multiple times with different content - ↑ Pham B et al. (2001). "Is there a "best" way to detect and minimize publication bias? An empirical evaluation". Evaluation & the Health Professions 24: 109–25. PMID 11523382. [e]
- ↑ Terrin N et al. (2005). "In an empirical evaluation of the funnel plot, researchers could not visually identify publication bias". J Clin Epidemiol 58: 894–901. DOI:10.1016/j.jclinepi.2005.01.006. PMID 16085192. Research Blogging.
- ↑ Lee K, Bacchetti P, Sim I. Publication of Clinical Trials Supporting Successful New Drug Applications: A Literature Analysis. PLoS Medicine. 2008 Sep 1;5(9):e191 EP -. DOI:10.1371/journal.pmed.0050191
- ↑ Rising, Kristin; Peter Bacchetti, Lisa Bero (2008-11-01). "Reporting Bias in Drug Trials Submitted to the Food and Drug Administration: Review of Publication and Presentation". PLoS Medicine 5 (11): e217 EP -. DOI:10.1371/journal.pmed.0050217. Retrieved on 2008-11-26. Research Blogging.