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This document discusses issues related to bias and quality in scientific research publications. It defines bias and lists many types of bias that can affect research, such as selection bias, performance bias, detection bias, and publication bias. It explains how biases like inadequate randomization or lack of blinding can influence research results. The document also discusses problems like selective reporting, research misconduct, and the need for self-regulation in research to improve quality and reduce waste.
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- 1. العلمي البحث عمادة سعودالملك جامعة
- 2. والردي الجيد بينالمنشور العلمي البحثء العقيل المحسن عبد سيناء االكلينكية الصيدلة بقسم مشارك استاذ الصيدلة كلية Salageel@ksu.edu.sa @alaqeels
- 6. Peer Review Process WilliamWhewell, peer-review pioneer Source: N AT U R E, VO L 5 3 2 . 2 0 1 6
- 7. Douglas Altman (1948–2018)
- 8. Douglas Altman (1948–2018)
- 9. An estimated $200billion —85% of global spending on research — is routinely wasted on poorly designed and redundant studies. (2010) Lancet 2009; 374: 86–89
- 11. Choosing the wrongquestions for research Doing studies that are unnecessary Ask a question Literature review Construct a hypothesis Try again Test with an experiment Analyze results Hypothesis is true Hypothesis is false Report results Doing studies that are poorly designed Failure to publish relevant research Biased or unusable reports of research
- 12. Bias Any trend inthe collection, analysis, interpretation, publication or review of data that can lead to conclusions that are systematically different from the truth. (Last J. A dictionary of epidemiology, 2001) Risk of bias.
- 13. Bias • Allocation bias •Ascertainment bias • Attention bias • Attrition bias • Chronological bias • Co-intervention bias • Contamination bias • Diagnostic access bias • Diagnostic suspicion bias • Detection bias • Detection-signal bias • Expectation bias • Exposure bias • Hawthorne effect • Incorporation bias • Insensitive measurement bias • Intervention bias • Lead time bias • Measurement bias • Membership bias • Neyman bias • Non-respondent bias • Observer bias • Prevalence-incidence bias • Proficiency bias • Publication bias • Recall bias • Referral bias • Reporting bias • Response bias • Sampling bias • Selection bias • Spectrum bias • Survival bias • Time lag bias • Timing bias • Unmasking bias • Verification bias (or partial verification bias) • Volunteer bias
- 14. DEMOCatalogofbias.org Your Date HereYour Footer Here 16
- 15. Implementation Reporting biasAttrition (dropout) bias Performance biasSelection bias Recruitment/Allocation Publication bias Analysis/Publication Channeling bias Confirmation bias Research Misconduct Detection bias Failure to publish Biased or unusable reportsDoing studies that are poorly designed
- 16. Implementation Reporting biasAttrition (dropout) bias Performance biasSelection bias Recruitment/Allocation Publication bias Analysis/Publication Allocation bias Confirmation bias Research Misconduct Detection bias Doing studies that are poorly designed
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- 18. Selection bias: theclassic example
- 19. Allocation bias • Systematicdifference in how participants are assigned to treatment and comparison groups in a clinical trial.
- 20. Randomisation of participantsin intervention studies Adequate allocation concealment
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- 22. The inadequate orunclear allocation concealment and biased estimates of intervention effects BMJ 2008;336:601
- 23. Implementation Attrition (drop out)bias Performance biasSelection bias Recruitment/Allocation Publication bias Analysis/Publication Alloction bias Research Misconduct Detection bias Reporting bias Doing studies that are poorly designed
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- 26. Performance bias Systematic differencesbetween groups in the care that is provided, or in exposure to factors other than the interventions of interest.
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- 28. The lack ofblinding and biased intervention effects BMJ 2008;336:601
- 29. Methods to Establish Blinding in RCTs PLOSMedicine 3(10): e425. https://doi.org/10.1371/journal.pmed.0030425
- 30. Methods of Blinded Outcome Assessment PLOS Medicine3(10): e425. https://doi.org/10.1371/journal.pmed.0030425
- 31. Implementation Attrition (drop out)bias Performance biasSelection bias Recruitment/Allocation Publication bias Analysis/Publication Allocation bias Reporting bias Research Misconduct Detection bias Failure to publish Biased or unusable reports
- 32. Publication Bias andselective reporting: the Tamiflu Experience Source: Tamiflu capsules. Photograph: Per Lindgren/REX via The Guardian Tom Jefferson
- 34. Publication Bias Journal ofEvaluation in Clinical Practice Volume 20, Issue 6, pages 908-914, 12 MAY 2014 DOI: 10.1111/jep.12147
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- 36. Publication bias andSelective outcome reporting
- 37. (Illustration: Margaret Shear,Public Library of Science) PLOS Medicine 2(5): e138. https://doi.org/10.1371/journal.pmed.0020138 Medical Journals Are an Extension of the Marketing Arm of Pharmaceutical Companies.
- 38. DEMOClinicalTrials WHO ICTP Your DateHere Your Footer Here 40
- 39. Implementation Reporting biasAttrition (dropout) bias Performance biasSelection bias Recruitment/Allocation Publication bias Analysis/Publication Allocation bias Reporting bias Research Misconduct Detection bias
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- 41. Justifications for retraction (n=4,232) PLOS ONE 7(10): e44118. https://doi.org/10.1371/journal.pone.0044118 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0044118 Retraction
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- 49. والرديء الجيد بينالمنشور العلمي البحث
- 52. DEMOEquator Network Guidelines YourDate Here Your Footer Here 55
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- 55. شكرا العقيل المحسن عبدسيناء االكلينكية الصيدلة بقسم مشارك استاذ الصيدلة كلية Salageel@ksu.edu.sa @alaqeels