Study Designs: Observational Studies & Randomized Controlled Trials

Day 2Ashish Advani, PharmD

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ObjectivesParticipants should be able to:Evaluate different types of primary literature for specific limitations2

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Evaluating Primary LiteratureAuthorShould have no:Preconceived notions about agent evaluatedConflict of interestWriting should be free of opinions or reflections of authors attitude

Smith, GH, Norton LL, Ferrill, MJ. Evaluating Drug Literature. ASHP Clinical Skills Program. Bethesda, MD: American Society of Hospital Pharmacists, Inc.; 1995: p. 1-202.clearly superior remarkable improvement3

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Evaluating Primary LiteratureIntroductionLiterature review should be accurate and balancedSmith, GH, Norton LL, Ferrill, MJ. Evaluating Drug Literature. ASHP Clinical Skills Program. Bethesda, MD: American Society of Hospital Pharmacists, Inc.; 1995: p. 1-202.AbstractShould fairly represent the study design, objective, methods, and results4

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Evaluating Primary LiteratureMethodsDesign should:Address study objective

Allow for support or rejection of null hypothesis Control: active or placeboParallel vs. crossover designUse appropriate analysis: intent to treat vs. per protocol

Smith, GH, Norton LL, Ferrill, MJ. Evaluating Drug Literature. ASHP Clinical Skills Program. Bethesda, MD: American Society of Hospital Pharmacists, Inc.; 1995: p. 1-202.5

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Evaluating Primary LiteratureMethodsIntent to treat analysis- how to handle missing data?Hollis S et al. BMJ. 1999; 319: 67-674. Sndor PS et al. Neurology. 2005;64:713-5.

Last observation carried forward (LOCF)Extreme case analysisComplete case analysis

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Evaluating Primary LiteratureMethodsGroup selection should represent population and minimize selection biasOutcome measures should be clinically relevantTreatment selection should represent standard of careTrial should extend over sufficient timeframe

Smith, GH, Norton LL, Ferrill, MJ. Evaluating Drug Literature. ASHP Clinical Skills Program. Bethesda, MD: American Society of Hospital Pharmacists, Inc.; 1995: p. 1-202.7

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Evaluating Primary LiteratureMethodsGroup selection should represent population and minimize selection biasOutcome measures should be clinically relevant

Kastelein JJ et al. Am Heart J . 2005;149:234-9.

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Evaluating Primary LiteratureResults Should follow Objectives section and outcome measures presented in Methods sectionSafety should be addressedRigotti NA et al. Circulation 2010;121:221-9.

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Evaluating Primary LiteratureDiscussionInterpretation of data- statistical and clinical significance should be consideredTreatment benefits vs. risk should be fairly assessedNumber Needed to Treat (NNT) and Number Needed to Harm (NNH)Smith, GH, Norton LL, Ferrill, MJ. Evaluating Drug Literature. ASHP Clinical Skills Program. Bethesda, MD: American Society of Hospital Pharmacists, Inc.; 1995: p. 1-202.10

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Evaluating Primary LiteratureConclusionsShould be supported by information in the report

Smith, GH, Norton LL, Ferrill, MJ. Evaluating Drug Literature. ASHP Clinical Skills Program. Bethesda, MD: American Society of Hospital Pharmacists, Inc.; 1995: p. 1-202.

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Questions?12

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