Harm, Critical Appraisal
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Transcript of Harm, Critical Appraisal
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8/13/2019 Harm, Critical Appraisal
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Critical Appraisal
EMB Harm
Isti Ilmiati Fujiati
Dept. Ilmu Kedokteran Komunitas
FK USU
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Artikel tentang Harm
Title:
CLOPIDOGREL Versus ASPIRIN andESOMEPRAZOLE to PREVENT
ULCER BLEEDING
The New England Journal of Medicine
2005
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There has been no prospective trail to assesswhether clopidogrel is an alternative to aspirinplus a proton-pump inhibitor for patients at risk
for ulcer.
Hypothesis:
Clopidogrel would not be inferior to aspirin plusesomeprazole in the prevention of recurrentulcer bleeding among the high risk patients.
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Research design:
Randomized clinical trial (RCT): prospective,
randomized, double-blind trial
Ethics committee approval
Informed consentAdjudication committeestudy end points
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Random assign:
Clopidogrel daily + esomeprazole placebo twicedaily
Aspirin daily + esomeprazole twice daily Follow up: 12 months
Clinical outcome: recurrent ulcer bleeding
Based on assumptions the sample sizecalculation would be: total sample 319,consecutive sampling
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Are the results of this harm study valid?1. Were there clearly defined groups of patients,similar in all important ways other than exposure
to the treatment or other cause?
Yes. Randomization would tend to make the two groupsidentical. It balances the groups for cofounders.
o Randomization random numbers Eligible patients based on criteria:
o Inclusion: ulcer healing, H.pylori (-), anticipated regular used use ofantiplateleto Exclusion
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2. Were treatments/exposures and clinical outcomesmeasured in the same ways in both groups (Was
the assessment of outcomes either objective or
blinded to exposure)?
Yes, Treatments: seal envelopes; drugs identicalOutcomes: Endoscopy was performed in a treatment-blinded fashion to determine the ulcer.
Are the results of this harm study valid?
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3. Was the follow-up of study patients sufficientlylong (for the outcome to occur) and complete?
Are the results of this harm study valid?
Yes,long up to 15% of those taking aspirin whohave a history of bleeding from ulcers hadrecurrent bleeding within one year.
follow up12 monthcompletesample size calculation: 319 patientswith assumption 10% loss to follow-up.
Nearly 320 patients completed follow-up.
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4. Do the results of the harm study fulfill some ofthe diagnostic test for causation?
Are the results of this harm study valid?
Yes,Another study reported that 12 who took clopidogrel hadulcer bleeding within one year.clopidogrel impairs the healing of gastric ulcers bysupressing the release of platelet-derived factors.
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1. What is the magnitude of the associationbetween the exposure and outcome
Are the valid results of this harm study important?
RR = ? NNH =?
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Importance:
Recurrent
Bleeding (+)Recurrent
Bleeding (-)
total
clopidogrel 13 148 161
Aspirin andesomeprazol
1 158 159
total 14 306 320
RELATIVE RISK
(RR) = A/(A+B) : C/(C+D)
= 13/161 : 1/159
= 0.081/0.0063
=12.86
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NNH = 1 / { A/(A+B)} {C/(C+D)}NNH = 1/ 0.081-0.0063NNH= 1/0.0747NNH= 13.4
We need 13 patients to be exposed to clopidogrel toproduce one additional recurrent ulcer bleeding ofgastrointestinal events.
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2. What is the precision of the estimate of theassociation between the exposure and theoutcome
Are the valid results of this harm study important?
RR with Confidence interval 95%: 11,49-14,19
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1. Is our patient so different from thoseincluded in the study that its results cannotapply?
No, our patients mostly similar to the patientsin the study
2. What is our patients risk of benefit andharm from the agent?avoiding the recurrent ulcer bleeding fromclopidogrel
Can this valid and important evidence about harm beapplied to our patient?
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3. What are our patients preferences, concerns andexpectations from this treatment?
no more symptoms of gastric bleeding as
consequences of clopidogrel therapy.
4. What alternative treatments are available?Yes,aspirin plus esomeprazole therapy or takingaspirin with enteric coated preparation.clopidogrel may given to patient with no
history of gastric ulcers.
Can this valid and important evidence about harm beapplied to our patient?