实证医学之经验谈.ppt

按一下以編輯母片標題樣式,按一下以編輯母片,第二層,第三層,第四層,第五層,*,What is Evidence-Based Medicine(EBM)?,Evidence-based medicine(EBM)requires the integration of the best research evidence with our clinical expertise and our patients unique values and circumstances.,By,best research evidence,By,clinical expertise,By,patient values,By,patient circumstances,Evidence-Based Medicine(EBM),是整合目前臨床上最好的研究結果與配合醫師專業能力，針對病患問題在各種不同的臨床環境與個人價值下，做最適當的診治模式。,How do We Actually Practice EBM?,Step 1,:converting the need for information(about prevention,diagnosis,prognosis,therapy,causation,etc.)into,an answerable question,.,Step 2,:tracking down,the best evidence,with which to answer that question.,Step 3,:,critically appraising that evidence,for its validity(closeness to the truth),impact(size of the effect),and applicability(usefulness in our clinical practice).,Step 4,:,integrating the critical appraisal,with our clinical expertise and with our patients unique biology,values,and circumstances.,Step 5,:,evaluating our effectiveness and efficiency,in executing steps 14 and seeking ways to improve them both for next time.,Incorporating EBM into Inpatient Rounds,Incorporating EBM into Inpatient Rounds,Can Synopses of Evidence Really Get There That Fast?,Several formats including,Structured synopses on paper in a binder(“big red book”,“medicine consult notebook”),Notebook computer carried by cart,Portable text book format(e.g.,Clinical Evidence,or,Evidence Based Acute Medicine,),PDA with concise summaries,Instant electronic access,PubMed,Cochrane Reviews,ACP Journal Club Online,Evidence-Based On Call,and Clinical Evidence,for both PCs and PDAs.,實證醫學教學三種方式,臨床個案模式的實證演練,以證據模式來教導臨床醫學,教導特定實證醫學的技巧,臨床個案模式的實證演練,使用臨床證據於病患照顧上。,以實際照顧病患個案來教學。,如何整合證據作為臨床判斷的過程。,舉例：,一位住院病患有上肢深度靜脈曲張；問題：你知道這樣的病人具有哪些潛在性疾病？比例為何？診斷流程表為何？,以證據模式來教導臨床醫學,使用臨床證據於病患照顧上的學習模式。,將實證醫學觀念與其他的臨床知識結合，用於教學上。,整合實證醫學與其他臨床醫學知識後用於病患身上結果的評核。,舉例：,(1),當你聽到病患的心音有,S3 gallop,時，你診斷他具有心臟衰竭的正確性為何？,(2),一位下腹疼痛的病患到急診就診後，你的診斷懷疑是急性闌尾炎；問題：你知道這樣的疾病常發生在年輕或老年人？比例為何？你知道有,Alvarado score,嗎？如何使用？可以不開刀僅使用抗生素就可以？,教導特定實證醫學的技巧,如何簡潔的瞭解與使用證據。,以教練的方式來教學。,實際演練實證醫學五大步驟,(,如何詢問問題？如何尋找資料？如何評核證據？如何應用證據？如何評估應用這些資料於臨床執業過程的正確性、實用性與可行性。,舉例：當我們在學習照顧一位新診斷卵巢癌的病患時，你在臨床上應該如何結合臨床知識佐以實證醫學觀念去面對她？,Asking Questions,Exercise:study designs,What is the question(PICO)of the study?,What is the purpose of the study?,Intervention,Frequency(incidence or prevalence),Diagnostic accuracy,Prognosis(or natural history),Aetiology and risk factors,Which study type would give the highest quality evidence to answer the question?(level of evidence),Which is the best study type that is also feasible?,What is the study type used?,Formulate an Answerable Question,ExampleStockings for long flights?,A 43 year old male asked for some repeat prescriptions and advice about preventing deep vein thrombosis on a 12 hour flight(his brother had had one last year).You suggest stockings as the most effective prevention.,Question,P,atient or,P,opulation:_In patients on long flights_,I,ntervention or,I,ndicator:_do compression stockings_,C,omparator:_no compression stockings_,O,utcome:_prevent deep vein thrombosis(DVT)_,Question sentence:,In patients on long flights(P),do compression stockings(I)prevent DVT(O)?,Library Searching Session,Using PubMed as an example:,Go to,www.pubmed.gov,and select Clinical Queries,Select the appropriate Category(usually“therapy”which is the default),Type in the most crucial single element of your PICO search(usually the I or the P),If your search returns no articles then click the“Broad”scope,If your search returns more than 30 articles then try adding more PICO elements,e.g,if you used only the“I”now try searching the I and P,Select the best single article and record why you choose the article you did.,Critical Appraisal of a Therapy Study,You are seeing a 48 year old man who has just recovered from idiopathic pericarditis and he is asking about the chance of recurrence and whether he can do anything to prevent it.You recall hearing something about a new trial recently,but cant remember the details.,Critical Appraisal of a Therapy Study,Decide what question(PICO)the study asked and answered,Whether the internal validity of the study is sufficient to allow firm conclusions(all studies have some flaws;but are these flaws sufficient to discard the study?),Critical Appraisal of a Therapy Study,If the study is sufficiently valid,look at and interpret the resultswhat is the relevance or size of the effects of the intervention?What is the Relative Risk Reduction(RRR)and Absolute Risk Reduction(ARR)?,Decide whether and how the results would apply to our patient above.Then role play explaining the condition and treatment to a patient using the following steps:,The prognosis,ie.Chance of recurrence,The impact of treatment on this,Critically Appraised Topic Presentation Template,Give a description of the clinical situation and the clinical question you need to answer.,Question(PICO):,Give your search strategy including:(a)database used,(b)search terms used,and(c)number of papers identified,and(d)why did you choose the particular article?,Critically Appraised Topic Presentation Template,What was the question of the study?Appraise the validity of the study.,What were the results of the study?,State how the study applies to the patient you identified.,CLINICAL SCENARIO,A 1-year-old boy is seen in our office due to cough with sputum and mild short of breath(SOB)for 1 day.He was relative normal before.This time,he had the symptoms of cough and SOB with mild wheezs on occasion.Fever with up to 38.3,0,C was noted.The physical examination revealed increase using of respiratory accessory muscle,and high-pitch wheez over bilateral basal lungs.The laboratory examination revealed mild leukocytosis and CXR showed increased infiltration over both basal lung field.,Critically Appraised Topic Presentation Example,The patient&clinical question,A 1 year old boy with first-time,bronchiolitis,visits our OPD.You may suggest that bronchodilators can produce small short-term improvements in clinical score and oxygenation.,Question(PICO):,In infants with,bronchiolitis,(P),do bronchodilator(I)provide benefits in clinical improvement(O)?,Critically Appraised Topic Presentation Example,Search strategy,PubMed,:Clinical queries(with therapy filters),Bronchiolitis,AND bronchodilator,72 papers included 1 Cochrane Database Systemic Rev.2006,Jul.,A review article included 22 clinical trial and 1428 infants.,Critically Appraised Topic Presentation Example,The studythe question and appraisal,Study Question:,In infants with,bronchiolitis,do bronchodilator provide more benefits in clinical improvement than placebo?,Critically Appraised Topic Presentation Example,The studythe question and appraisal,Randomisation,:All were randomized,double-blind,placebo control trials.,Ascertainment,:Multiple,RCTs,analyzed in this meta-analysis review;this is adequate.,Measurement,:double-blind in treatment design through evaluation by clinical score,oxygenation,rate of hospital admission,duration of hospitalization.,Critically Appraised Topic Presentation ExampleResults,Twenty-two clinical trials with 1428 infants with,bronchiolitis,were included in this review.,In eight trials,with 468 infants,there was no improvement in clinical score for 43%of those treated with bronchodilators compared to 57%of those treated with placebo(odds ratio(OR)for no improvement 0.45,95%confidence interval(CI)0.15 to 1.29).,There was a statistically significant but clinically modest improvement in the overall average clinical score(standardized mean difference(SMD)-0.48,95%CI-0.62 to-0.33).,Critically Appraised Topic Presentation ExampleResults,There was no statistically significant improvement in oxygenation overall(weighted mean difference(WMD)-0.57,95%CI-1.17 to 0.03).,Subgroup analyses showed a slightly greater effect size in outpatient studies,where there were shorter follow up durations,than in inpatient studies for both,oximetry,(outpatients WMD-0.84,95%CI-1.59 to-0.10 versus inpatients WMD-0.25,95%CI-1.18 to 0.67)and average clinical score(outpatients SMD-0.68,95%CI-0.87 to-0.49 versus inpatients SMD-0.23,95%CI-0.44 to-0.01).,Critically Appraised Topic Presentation ExampleResults,Bronchodilator recipients showed no improvement in the rate of hospital admission after treatment as outpatients(18%versus 26%,OR 0.70,95%CI 0.36 to 1.35)or duration of hospitalization for inpatients(WMD 0.02,95%CI-0.32 to 0.36).,The inclusion of studies that enrolled infants with recurrent wheezing may have biased the results in favor of bronchodilators.,Critically Appraised Topic Presentation ExampleResults,AUTHORS CONCLUSIONS:Bronchodilators produce small short-term improvements in clinical scores.This small benefit must be weighed against the costs and adverse effects of these agents.,Critically Appraised Topic Presentation ExampleImplication for Practice,Bronchodilators produce small short-term improvements in clinical scores among infants with,bronchiolitis,and may slightly improve oxygenation in those treated as outpatients.,However,given the high costs,incidence of adverse effects and uncertain efficacy based on the findings of this meta-analysis,bronchodilators cannot be recommended for routine management of first-time,wheezers,who present with the clinical findings ofbronchiolitis,.,Bronchodilators should not be used in patients who are hospitalized with,bronchiolitis,.,Critically Appraised Topic Presentation ExampleImplication for Practice,Critically Appraised Topic Presentation Example(2),The patient&clinical question,A 43 year old male asked for some repeat prescriptions and advice about preventing deep vein thrombosis on a 12 hour flight(his brother had had one last year).You suggest stockings as the most effective prevention.,Question(PICO):,In patients on long flights(P),do compression stockings(I)prevent DVT(O)?,Critically Appraised Topic Presentation Example(2),Search strategy,PubMed,:Clinical queries(with therapy filters),Flight*AND stocking*AND DVT,6 papers included 2 separate trials,The,Scurr,article was the larger trial,and quality appeared equal,Critically Appraised Topic Presentation Example,The studythe question and appraisal,Study Question:,In patients on flights over 8 hours in economy class,do Grade-I below-knee compression stockings,compared to no stocking,prevent ultrasound-detected DVT?,Critically Appraised Topic Presentation Example,The studythe question and appraisal,Randomisation,:was by sealed envelope(not ideal)but lead to reasonable balance through more female appeared to receive stockings than males.,Ascertainment,:there was an 86%,followup,and ultrasound in each arm;this is adequate.,Measurement,:through stockings were removed pre-ultrasound,the,sonographer,may have seen the stocking mark and hence been,unblinded,.,The study has some flaws,but these are probably insufficient to explain the size of the results,Critically Appraised Topic Presentation Example,The results,DVT occurred in 12%of the No stocking group and 0%of the Stocking group.,Relative risk reduction of 100%and an absolute risk reduction of 12%(95%CI 69-100),The NNT(number needed to treat)is 9.However,there was a small increase in superficial,thrombophlebitis,.,Critically Appraised Topic Presentation Example,How the results apply,My patient is a little younger than the average of 62 years seen in the trial,and hence probably at somewhat lower risk.Nevertheless,this is a simple cheap and effective prevention procedure,which I would recommend to him.,Are the Results of This Single Preventive or Therapeutic Trial Valid?,Was the assignment of patients to treatments randomized?,Yes.Refers to another article that describes the methods more fully.Note that in ACP Journal Club it mentioned that allocation was concealed.,Was the randomization list concealed?,Yes.,Was follow-up of patients sufficiently long and complete?,99%follow-up at a mean of 5 years.,Were all patients analyzed in the groups to which they were randomized?,An intention to treat analysis was completed.,Were patients,clinicians and study personnel kept“blind”to treatment?,Yes.Participants,clinicians,data collectors and outcomes assessors were blinded.,Were the groups treated equally,apart from the experimental treatment?,Yes.,Were the groups similar at the start of the trial apart from the experimental therapy?,Yes.,OUR CALCULATIONS,95%CI,72,1.4%,25%,4.3%,5.7%,1/ARR,CER EER,CER EER,CER,EER,CER,Number needed to treat(NNT),Absolute risk reduction(ARR),Relative risk reduction(RRR),Can We Apply This Valid,Important Evidence About Therapy in Caring for Our Patient?,Do these results apply to our patient?,Is our patient so different from those in the study that its results cannot apply?,No.Includes patients 4080 years old with TIA,carotid endarterectomy and normal lipid profiles.,Is the treatment feasible in our setting?,Yes it is available but must explore with patient if he is willing to take it.,What are our patients potential benefits and harms from the therapy?,Method I,:f,Risk of the outcome in our patient,relative to patients in the trial.,Expressed as a decimal:_,NNT/f=_/_=_,(NNT for patients like ours),Method II,:1/(PEERRRR),Our patients expected event rate(PEER)if they received the control treatment:,PEER=_,1/(PEERRRR)=1/_=_,(NNT for patients like ours),Study includes a subgroup analysis looking at the patients aged 7580 years at study entry with outcomes of major vascular event.CER=32.3%,EER=23.1%.Therefore,RRR is 29%and NNT is 11.Are our patients values and preferences satisfied by the regimen and its consequences?,Do we and our patient have a clear assessment of their values and preferences?,Need to explore with patient.,Are they met by this regimen and its consequences?,Need to explore with patient.,Writing Structured Summaries of Evidence-based Learning,or CATs(critically appraised topics),Title,:declarative sentence that states the clinical bottom line.,Clinical question,:four(or three)components of the foreground question that started it all.,Clinical bottom line,:concise statement of best available answer(s)to the question.,Evidence summary,:description of methods and/or results in concise form(e.g.table).,Comments,:about evidence(e.g.limitations)or how to use it in your own setting.,Citation(s),:include evidence appraised and other resources,if appropriate.,Appraiser,:so youll know who did the appraising when you return to it later.,Date CAT was“born”/expiration date,:so folks will know when to look again.,Presentations,For your brief presentation:,Please hand a copy of your review and paper to the tutor before presenting.,You will have about 7 minute to present and 3 minutes for discussion.,This should require about 2-3 overheadse.g.,one for the patients,one for the search and paper,and one for application to the individual patient.,Diagnostic Essentials,CLINICAL SCENARIO,假如我們現在正在診治一位貧血病患，且目前已知造成他貧血的原因有50%機會是缺鐵性貧血，我們想要以一個有用的血清標記ferritin 作為偵測此病患確定為缺鐵性貧血的可能性。因此我們去尋求外在的證據，包括病患的血清ferrin值為60 mmol/