EBM on Therapy

TherapyEVIDENCE-BASED MEDICINE

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This set contains:

1. On the need for EBM (big info needs vs out-dated texts, little time to read, deteriorating knowledge and performance, CME doesnt improve clinical behaviour, EBM definition, how to practice EBM, rounds and educational prescriptions and journal clubs, the Cochrane and ACPJC/ EBM journals, guidelines and strategies for improving clinical behaviour)

2. Audits of practice to determine whether they are evidence-based (mostly on internal medicine, but slides on John Geddes et for psychiatry, Peter McCulloch et al for Surgery, and Gill et al for GP)

At several points youll need to tip in other slides, and well do this when we can, and provide original artwork where we cant.

EvidenceValidityImportance

or

ImportanceValidity

Clinical ScenarioA 75-year-old man is seen in our office after being discharged from hospital 2 weeks previously. During this admission he underwent a carotid endarterectomy after suffering a transient ischemic attack (TIA), and being diagnosed with significant carotid stenosis. His hospital stay was uncomplicated and his discharge medications included metoprolol 50 mg twice daily for hypertension and aspirin 81 mg daily.

Clinical ScenarioToday, he has brought us an article from the Internet describing the benefits of statins for stroke prevention and he wonders what this medication is and if he should take it. Our note from his last visit showed that his total cholesterol was 5mmol/L, HDL-cholesterol was 2.0mmol/L, and LDL-cholesterol was 2mmol/L. His examination was unremarkable.

Steps in Practicing EBMConvert the need for information into an answerable question.Track down the best evidence with which to answer that question.Critically appraise the evidence for its validity, impact, and applicability.Integrate the evidence with our clinical expertise and our patients characteristics and values.Evaluating our effectiveness and efficiency in executing steps 14 and seeking ways to improve them both for next time.

Clinical QuestionComponents of foreground question (PICO):

Patient and the problem:Intervention:Comparison:Outcome of interest:Patient with history of TIA, carotid endarterectomy, hypertension, and normal lipid profileStatinNoneStroke

Clinical QuestionInapatient with history of TIA, carotid endarterectomy, hypertension, and normal lipid profile, does therapy with a statin decrease risk of stroke?

TYPES OF THERAPEUTIC REPORTS Individual trialsSystematic reviewClinical decision analysisEconomic analysisClinical practice guidelinesQualitative studiesN-of-1 study

Search StrategyMedline database:

http://www.ncbi.nlm.nih.gov/pubmed/

The EvidenceHeart Protection Study Collaborative Group. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised-placebo controlled trial. Lancet 2002; 360: 722.MRC-BHF Heart Protection Study.pdf

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID?

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 1.Was the assignment of patients to treatment randomized? In the MRC trial that we found to answer our question about the effectiveness of statin therapy, the title states that it is a randomized trial, and a quick scan of the methods refers us to another article for complete details:

Patients and methodsDetails of the study objectives, design, and methods have been reported previously12,23 (including the protocol on the study website: www.hpsinfo.org), ..

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 2.Was the randomization concealed? (apakah pengacakan nya tersembunyi)DesignRandomised (allocation concealed*), blinded (participants, clinicians, data collectors, and outcome assessors),* placebo controlled trial with mean follow up of 5 years. Evid Based Med 2003;8:10

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 3.Were the groups similar at the start of the trial? In the statin study, there were no significant differences between patients receiving placebo and those receiving statin. The large size of the study (and the use of minimisation) produced good balance between the treatment groups for the main prerandomisation prognostic features that were measured, and should have done likewise for those that were not.

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 4.Was follow-up of patients sufficiently long and complete? In our statin study, follow-up was 99% at a mean of 5 years.

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 5.Were all patients analyzed in the groups to which they were randomized? The statin study used an intention-to-treat analysis and we can feel confident that it has passed all major validity criteria. As a consequence, the intention-to-treat comparisons in this report assess the effects of about two-thirds of simvastatin-allocated participants actually taking 40 mg simvastatin daily.

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 6.Were patients, clinicians, and study personnel kept blind to treatment? The MRC trial states that it was a double-blind placebo-controlled trial. Blinded: participants, clinicians, data collectors, and outcome assessors.

ARE THE RESULTS OF THIS INDIVIDUAL STUDY VALID? 7. Were groups treated equally, apart from the experimental therapy? This is a randomised placebo-controlled trial.

ARE THE VALID RESULTS OF THIS INDIVIDUAL STUDY IMPORTANT?

ARE THE VALID RESULTS OF THIS INDIVIDUAL STUDY IMPORTANT? 1.What is the magnitude of the treatment effect?

ARE THE VALID RESULTS OF THIS INDIVIDUAL STUDY IMPORTANT?2.How precise is this estimate of the treatment effect?

ARE THE VALID, IMPORTANT RESULTS OF THIS INDIVIDUAL STUDY APPLICABLE TO OUR PATIENT?

ARE THE VALID, IMPORTANT RESULTS OF THIS INDIVIDUAL STUDY APPLICABLE TO OUR PATIENT? 1.Is our patient so different from those in the study that its results cannot apply? No. Our patient fulfils the inclusion criteria of the study.

ARE THE VALID, IMPORTANT RESULTS OF THIS INDIVIDUAL STUDY APPLICABLE TO OUR PATIENT? 2.Is the treatment feasible in our setting? Yes. The drug is widely available in Indonesia. Simvastatin OGB Dexa capsule costs only Rp 13,991 (10 mg x 30's) (http://www.mims.com/Indonesia/drug/info/)

ARE THE VALID, IMPORTANT RESULTS OF THIS INDIVIDUAL STUDY APPLICABLE TO OUR PATIENT? 3.What are our patients potential benefits and harms from the therapy? In our statin example, the study reported an NNT of 72, so wed need to treat 72 patients like those in the trial with a statin for a mean of 5 years to prevent one more of them from experiencing a stroke.If, however, we judge that our patient is at three times the risk of stroke without treatment as the patients in the control group, ft = 3 and NNT/ft = 72/3 = 24. This means that we would only need to treat 24 higher-risk patients like ours for 5 years to prevent an additional stroke.

ARE THE VALID, IMPORTANT RESULTS OF THIS INDIVIDUAL STUDY APPLICABLE TO OUR PATIENT? 4.What are our patients values and expectations for both the outcome we are trying to prevent and the treatment we are offering? The clinical bottom line is that in patients with a high 5 year risk of death, simvastatin safely reduced all cause mortality, vascular mortality, and vascular events.

Resolution of The Case ScenarioThe patient should take simvastatin to prevent stroke.


1

1

This set contains:

1. On the need for EBM (big info needs vs out-dated texts, little time to read, deteriorating knowledge and performance, CME doesnt improve clinical behaviour, EBM definition, how to practice EBM, rounds and educational prescriptions and journal clubs, the Cochrane and ACPJC/ EBM journals, guidelines and strategies for improving clinical behaviour)

2. Audits of practice to determine whether they are evidence-based (mostly on internal medicine, but slides on John Geddes et for psychiatry, Peter McCulloch et al for Surgery, and Gill et al for GP)

At several points youll need to tip in other slides, and well do this when we can, and provide original artwork where we cant.

Documents

EBM on Therapy