(Question Formulation) (Evidence Search) (Critical Appraisal) (Evidence Application) (Outcome Evaluation)

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Evidence Search

SystemSummariesSynopsesSynthesesStudies

(Meta-analysis)(RCT)(RCT)

Search DatabasePubMedCochrane Library

Cochrane Library_Advanced SearchP and I and C and O

PubMedMy NCBIMeSHMeSHnatural language ANDORAlertEndNote

Queries 1

20091008P and I and C and O

20091008*SRRCTin process163PICO 163,SR/RCTin process,

Queries 2_Clinical Queries- Search by Clinical Study Category

SearchQueriesResult#5(#4) AND Therapy/Narrow[filter]11

Queries 3_Clinical Queries- Find Systematic Reviews

SearchQueriesResult#6(#4) AND systematic[sb]8

Queries 4 _in processin process(2010/06/08)

SearchQueriesResult#7(#4) AND (In process[sb] OR publisher[sb] OR pubmednotmedline[sb])7

Queries 5_Combination16324

SearchQueriesResult#8#5 OR #6 OR #724

Studies Extraction References (25) Meta-Analysis 2010 (1)RCT (0) PubMed (24) Cochrane(1) References 2010 (4) Meta-Analysis 2010 (1) Excluded from Title & Abstract (3)

Critical Appraisal Are the results of the article valid? (V) What are the result? (I) Will the results help me in caring for patients? (P)

Grade of RecommendationLevel of EvidenceTherapy/Prevention,Aetiology/HarmA1aSR (with homogeneity) of RCT1bIndividual RCT (with narrow CI)1cAll or noneB2aSR (with homogeneity) of cohort study2bIndividual cohort study (included low quality RCT; e.g.,

Validity: Randomized Concealed assignment Sufficiently long & complete follow-up (> 80%) Double blinded Groups similar & treated equally except for the therapy

Important: The magnitude of the treatment effect NNT: number needed to treatNNT= 1/ARR = 1 / l CER EER l, ARR: absolute risk reduction NNH: number needed to harmNNH= 1/ARI = 1 / l EER CER l, ARI: absolute risk increase RRR: relative risk reduction = (CER-EER)/CER RRI: relative risk increase = (EER-CER)/CER

Calculation Experimental Event Risk (EER) = a/(a+b) Control Event Risk (CER) = c/(c+d) Relative Risk (RR) = EER/CER = (a/(a+b))/ (c/(c+d)) Experimental Event Odd (EEO) = a/b Control Event Odd (CEO) = c/d Relative Odds = Odds Ratio = EEO/CEO = (a/b)/ (c/d) Odds: a ratio of events to non-events ()

TreatmentEventPositiveNegativeExposedabNot exposedcd

: http://www.cebm.net

SYSTEMATIC REVIEWAre the results of the review valid ?

Screening Questions (Yes/No)What question (PICO) did the systematic review address? Is it unlikely that important, relevant studies were missed? Were the criteria used to select articles for inclusion appropriate? Were the included studies sufficiently valid for the type of question asked? Were the results similar from study to study? (Cochrane Q ?, Q/df ?, I2 ?)How are the results presented? (Forest plot?)

Critical Appraisal Skills Programme: http://www.phru.nhs.uk/pages/phd/CASP.htm

Critical Appraisal Tools

Critical Appraisal Skills Programme (CASP)Systemic Review

A. Is the study valid ()?1. Did the study ask a clearly-focused question?

Consider if the question is focused in terms of :the population studiedthe intervention given or exposurethe outcomes considered

PICO

2. Did the review include the right type of study?Consider: Address the reviews questionHave an appropriate study designIs it worth continuing?

3.Did the reviewers try to identify all relevant studies? ()?

Consider: which bibliographic databases were usedif there was follow-up from reference listsif there was personal contact with expertsif the reviewers searched for unpublished studies if the reviewers searched for non-English-language studies

4. Did the reviewers assess the quality of the included studies?

Consider: if a clear, pre-determined strategy was used to determine which studies were included. Look for: - a scoring system - more than one assessor

5. If the results of the studies have been combined, was it reasonable to do so?

Consider whether:the results of each study are clearly displayed the results were similar from study to study (look for tests of heterogeneity)the reasons for any variations in results are discussed

6.How are the results presented and what is the main result?

Consider: how the results are expressed (e.g. odds ratio, relative risk, etc.)how large this size of result is and how meaningful it isHow you would sum up the bottom-line result of the review in one sentence

7. How precise are these results?

Consider: if a confidence interval were reported. Would your decision about whether or not to use this intervention be the same at the upper confidence limit as at the lower confidence limit?if a p-value is reported where confidence interval are unavailable

8.Can the results be applied to the local population?

Consider whether:the population sample covered by the review could be different from your population in ways that would produce different resultsyour local setting differs much from that of the reviewyou can provide the same intervention in you setting

9. Were all important outcomes considered?

Consider outcomes from the point of view of the: Individualpolicy makers and professionalsFamily/carersWider community

10. Should policy or practice change as a result of the evidence contained in this review?

Consider: whether any benefit reported outweighs any harm and/or cost. If this information is not reported can it be filled in from elsewhere?

Consider outcomes from the point of view of the:individualpolicy maker and professionalsfamily/carerswider community

Consider whether:any benefit reported outweighs any harm and/or cost. If this information is not reported can it be filled from elsewhere?policy or practice should change as a result of the evidence contained in this trial