循证医学概论课件.ppt

1、Evidence-Based Medicine 循证医学循证医学Background1997年上海医科大学中西医结合研究所完成的“中华灵芝宝”动物实验证实：该药物具有抑瘤作用、保护免疫功能和放化疗减毒增效作用。中国科学院上海药物研究所完成“中华灵芝宝对多种培养人癌细胞生长的作用”。课题，结论证实该药物对多种白血病和人体实体癌细胞具有明显的抑制作用，并呈现较好的量效关系。1999年中国科学院上海生物研究所丁健研究员等实验表明，中华灵芝宝（现名：双灵固本散）能抑制拓扑异构酶I和拓扑异构酶II，造成癌细胞DNA单链或双链断裂，阻断癌细胞的无限制繁殖，导致癌细胞破裂凋亡。2001年上海预防医学研究院以

2、Ames试验和骨髓微核试验作了研究，结果表明中华灵芝宝具有抗突变作用。2002年国家药品监督管理局（SDA）批准中华灵芝宝转为“国药准字”B20020428，并更名为“双灵固本散”。Cell or animal is equal to humanBackground Traditional practice Model Clinicians are use convenient sources Factors that influence decision making.Senior doctors Patient request Pharmaceutical representatives

3、recommendation Local expert-based CMEOutdate!Background False evidence Anesthesia and Analgesia 2007 IF 2.214 2007 Total Cites 15960Definition Evidence Based Medicine is the conscientious,explicit,and judicious use of current best evidence in making decisions about the care of individual patients.Sa

4、ckett,D.L.BMJ 1996 Evidence-based medicine is the integration of best research evidence with clinical expertise and patient values Sackett,D.L.2001Definition EBM:A Practical Definition When there is evidence of benefit and value,do it.When there is evidence of no benefit,harm or poor value,dont do i

5、t.When there is insufficient evidence to know for sure,be conservative.And whatever we do,do it right!David EddyDefinition Clinical expertise临床技能临床技能外部证据外部证据External evidencesPatient Values and Preferences病人价值病人价值Clinicians Individual clinical expertise the increasing proficiency and judgement that

6、individual clinicians acquire through clinical experience and clinical practice.Clinicians EBM is a Lifelong learning model lifelong,self-directed,problem-based learning EBM propose methods to find and evaluate evidence.EBM converts the abstract exercise of reading and appraising the literature into

7、 the pragmatic process of using the literature to benefit individual patients while simultaneously expanding the clinicians knowledge base.Bordley,D.RClinicians The basic for EBMThe basic for EBMDefinition Clinical expertise临床技能临床技能外部证据外部证据External evidencesPatient Values and Preferences病人价值病人价值Exte

8、rnal evidences Best available external clinical evidence:clinically relevant research basic sciences of medicine patient-centred research External clinical evidence has a short doubling-time,and both invalidates previously accepted diagnostic tests and treatments and replaces them with new ones that

9、 are more powerful,more accurate,more efficacious,and saferExternal evidences Is All Evidence Created Equal?Oxford Centre for Evidence-based Medicine Levels of EvidenceThe Evidence PyramidHierarchy of evidence:arranges study designs by their susceptibility to biasPrimary Research Experimental observ

10、ationalSecondaryResearchFor quantitative studiesFor qualitative studies No consensus about the relative rigour of different methodsSystematic review双灵固本散Appraise evidencesType of QuestionSuggested best type of StudyTherapyRCTcohort case control case seriesDiagnosisProspective,blind comparison to a g

11、old standardEtiology/HarmRCT cohort case control case seriesPrognosisCohort study case control case seriesPreventionRCTcohort study case control case seriesClinical ExamProspective,blind comparison to gold standardCostEconomic analysisRight methods is crucialAppraise evidences Measure Objective：Surv

12、ival Lab test Radiology Subjective：Pain SymptomsExternal evidences Categories of Consensus In NCCN clinical guideline Category 1:There is uniform NCCN consensus,based on high-level evidence,that the recommendation is appropriate.Category 2:There is uniform NCCN consensus(or non-uniform NCCN consensu

13、sbut no major disagreement),based on lower-level evidence including clinical experience,that the recommendation is appropriate.Category 3:There is major NCCN disagreement that the recommendation is appropriate.Appraise evidences Endpoint alternative：relieve of symptom shrink of tumor Gold Standard：c

14、ure prolong survivalNot all the evidences are the same importanceHollingworth&Jarvik,Radiology 2007;244:31-38Flowchart of cost-effectiveness at each level of TA hierarchyTechnical PerformanceDiagnostic PerformanceDiagnostic ImpactTherapeutic ImpactImpact on HealthSource of Medical Information Collea

15、gues Conferences Drug Reps Textbooks Journals Internet/PatientsSource of Medical Information Primary MEDLINE，CBM Secondary Guidelines，Cochrane Lib Much more likely(than personal search and critical appraisal)to be true Saves the clinicians time Textbook Others？Conference Institutional or personal ex

16、perienceSource of Medical Information Interest group or organization Commercial Companys News or Brief Google,Yahoo!Open Mind and Be Very CarefullyQuick Information Guidelines Explicit evidence-based Evidence-based Research-based(highly referenced)Opinion-based“expert consensus”National Guideline Cl

17、earinghouse(http:/www.guideline.gov/)Cancer Care Ontarios Program in Evidence-Based Care(PEBC)and the Cancer Care Ontario Practice Guidelines Initiative(CCOPGI)http:/www.ccopebc.ca/Quick Information Cochrane Library-The Cochrane Collaboration Systematic reviews The current resource with the highest

18、methodological rigor For each clinical question,all of the English literature meticulously searched for randomized trials Large systematic reviews with valid methods+collaborative effort Conclusions are based on all the evidence from valid randomized trialsPDQ(Physician Data Query)http:/www.cancer.g

19、ov/cancer_information/pdq/Clinical Trial Database Current Controlled Trialshttp:/www.controlled- NIH ClinicalTrials.gov PubMed/MEDLINE http:/www.ncbi.nlm.nih.gov/PubmedEvidence-based Medicine Bases action on best evidence synthesis Good doctors use both individual clinical expertise and the best ava

20、ilable external evidence,and neither alone is enough.Without the former,practice risks becoming evidence-tyrannised,for even excellent external evidence may be inapplicable or inappropriate for an individual patient.Without the latter,practice risks becoming rapidly out of date,to the detriment of p

21、atients and patient-care.Definition Clinical expertise临床技能临床技能Patient Values and Preferences病人价值病人价值外部证据外部证据External evidencesThe Patients Individualize 个体化；Compliance 依从性；Informed consent 知情同意 Value Definition Clinical expertise临床技能临床技能Patient Values and Preferences病人价值病人价值外部证据外部证据External evidence

22、sOther factorsOther factors 1.Regulations1.Regulations 2.Medical insurance 2.Medical insuranceWhat EBM is Not EBM is not cook-book medicine Evidence needs extrapolation to the patients unique biology and values EBM requires that the best external evidence be integrated with individual clinical exper

23、tise and patient-choice in a bottom-up approach.External clinical evidence can inform,but can never replace,individual clinical expertise.EBM is not cost-cutting medicine when efficacy for the patient is paramount,costs may rise,not fallWhat EBM is Not EBM is not restricted to randomised trials The

24、randomised trial and systematic review are the“gold standard”for judging whether a treatment does more good than harm.However,some questions about therapy do not require randomised trials or cannot wait for the trials to be conducted.Sometimes the evidence we need will come from the basic sciences such as genetics or immunology.And if no randomised trial has been carried out for our patients predicament,we follow the trail to the next best external evidence and work from there.