2013/11/08

PICO

2000Sackett Sackett et al 2000

1. Asking an answerable question () 2. Tracking down the best evidence () 3. Critical appraisal () 4. Integrating the appraisal with clinical expertise and patients preference ()5. Evaluation the effectiveness and efficiency in executing steps 1-4 ()

A stroke patient who has long term gouty arthritisDoes gout cause a higher risk of stoke?

Acquire

AppraisalApply

PICOAskingEBMSir Austin Bradford Hill (1897-1991), English epidemiologist and statisticianHe described the clinical trial as being a CAREFULLY, and ETHICALLY, described experiment with the aim of answering some PRECISELY FRAMED QUESTIONGreater precision is required in the objectives. We need to haveA defined populationDefined endpointsRelatively few question to be answered.

1. (Clinical Question)Does gout cause a higher risk of stoke?

(PICO)P: Patient, Population I: InterventionC: ComparisonO: Outcome

Acquire

AppraisalApply

PICOAskingEBMPICO 1 Does gout cause a higher risk of stoke?

PICO type:TherapyPatient:Intervention:Comparison:Outcome:

2. Tracking down the best evidence(secondary databases) ACP journal club, Cochrane Library, UpToDate, MD Consult, Practice Guideline(primary databases) PubMed, OVID, Proquest~Google

EBM 1. PudMedabstract 2. OvidabstractFulltext 3. ProquestabstractFulltext 4. ClinicalkeyabstractFulltext Systemic Review () Meta-analysis () Randomized Controlled Trial () Controlled Trials

MeSH to identify every term for example

Acquire

AppraisalApply

PICOAskingSearching Strategy Finding out The Correct Keywords

Primary Term MeSH Term 12P(oror)andI(GoutorHyperuricemiaor)andC(oror)andO(strokeoror)

Acquire

AppraisalApply

PICOAskingSearching Strategy Finding out The Correct KeywordsKeywords from PICO item:(gout OR hyperuricemia) AND strokeMeSH to identify every term for example

Acquire

AppraisalApply

PICOAsking Systematic review: (gout OR hyperuricemia) AND (stroke OR cardiovascular disease)

Acquire

AppraisalApply

PICOAsking

The Evidence PyramidV. Animal researchV. In vitro (test tube) researchIV. Case series/ ReportsV. Ideas, Editorials, OpinionsIII. Case Control StudiesII. Cohort studiesI. Randomized Controlled Studies (RCT)I. Randomized Controlled Double Blind Studies Meta - analysisMeta-analysis Forest plot*Hierarchy of evidence: arranges study designs by their susceptibility to bias. (Level I~V)From: Oxford Center for EBM

Oxford Centre for Evidence-based Medicine - Levels of Evidence (March 2009) http://www.cebm.net/index.aspx?o=1025

Level Therapy/Prevention, Aetiology/HarmPrognosisDiagnosisDifferential diagnosis/symptom prevalence studyEconomic and decision analyses1aSR (with homogeneity*) of RCTs SR (with homogeneity*) of inception cohort studies; CDR validated in different populationsSR (with homogeneity*) of Level 1 diagnostic studies; CDR with 1b studies from different clinical centresSR (with homogeneity*) of prospective cohort studies SR (with homogeneity*) of Level 1 economic studies1bIndividual RCT (with narrow Confidence Interval)Individual inception cohort study with > 80% follow-up; CDR validated in a single populationValidating** cohort study with good reference standards; or CDR tested within one clinical centreProspective cohort study with good follow-up****Analysis based on clinically sensible costs or alternatives; systematic review(s) of the evidence; and including multi-way sensitivity analyses1cAll or noneAll or none case-seriesAbsolute SpPins and SnNoutsAll or none case-seriesAbsolute better-value or worse-value analyses 2aSR (with homogeneity*) of cohort studiesSR (with homogeneity*) of either retrospective cohort studies or untreated control groups in RCTsSR (with homogeneity*) of Level >2 diagnostic studiesSR (with homogeneity*) of 2b and better studiesSR (with homogeneity*) of Level >2 economic studies2bIndividual cohort study (including low quality RCT; e.g.,

5Level 1 Randomized controlled trials, RCTLevel 2Cohort studyLevel 3Case-control studyLevel 4Case seriesLevel 5Expert opinion Grading system for recommendations Grade ALevel 1 Grade BLevel 2 Grade CLevel 3 Grade DLevel 3

Oxford Centre for Evidence-based Medicine - Levels of Evidence (March 2009) http://www.cebm.net/index.aspx?o=1025

Level Therapy/Prevention, Aetiology/HarmPrognosisDiagnosisDifferential diagnosis/symptom prevalence studyEconomic and decision analyses1aSR (with homogeneity*) of RCTs SR (with homogeneity*) of inception cohort studies; CDR validated in different populationsSR (with homogeneity*) of Level 1 diagnostic studies; CDR with 1b studies from different clinical centresSR (with homogeneity*) of prospective cohort studies SR (with homogeneity*) of Level 1 economic studies1bIndividual RCT (with narrow Confidence Interval)Individual inception cohort study with > 80% follow-up; CDR validated in a single populationValidating** cohort study with good reference standards; or CDR tested within one clinical centreProspective cohort study with good follow-up****Analysis based on clinically sensible costs or alternatives; systematic review(s) of the evidence; and including multi-way sensitivity analyses1cAll or noneAll or none case-seriesAbsolute SpPins and SnNoutsAll or none case-seriesAbsolute better-value or worse-value analyses 2aSR (with homogeneity*) of cohort studiesSR (with homogeneity*) of either retrospective cohort studies or untreated control groups in RCTsSR (with homogeneity*) of Level >2 diagnostic studiesSR (with homogeneity*) of 2b and better studiesSR (with homogeneity*) of Level >2 economic studies2bIndividual cohort study (including low quality RCT; e.g.,

Acquire

AppraisalApply

PICOAsking Title: - Hyperuricemia and risk of stroke: a systematic review and meta-analysis.(2009)

Source:Arthritis Rheum. 2009 Jul 15;61(7):885-92

Level: 2a

Large epidemiologic studies have shown that hyperuricemia is associated with an increased incidence of coronary heart disease (CHD) and increased mortality in those withand withoutpreexisting CHD .

Fang J, Alderman MH. Serum uric acid and cardiovascular mortality the NHANES I epidemiologic follow-up study, 1971-1992. National Health and Nutrition Examination Survey. JAMA 2000; 283:2404.Freedman DS, Williamson DF, Gunter EW, Byers T. Relation of serum uric acid to mortality and ischemic heart disease. The NHANES I Epidemiologic Follow-up Study. Am J Epidemiol 1995; 141:637.Brand FN, McGee DL, Kannel WB, et al. Hyperuricemia as a risk factor of coronary heart disease: The Framingham Study. Am J Epidemiol 1985; 121:11.Niskanen LK, Laaksonen DE, Nyyssnen K, et al. Uric acid level as a risk factor for cardiovascular and all-cause mortality in middle-aged men: a prospective cohort study. Arch Intern Med 2004; 164:1546.Choi HK, Curhan G. Independent impact of gout on mortality and risk for coronary heart disease. Circulation 2007; 116:894.

Proposed mechanisms for such an increase in risk include the development of hypertension and oxidative stress.

Johnson RJ, Segal MS, Srinivas T, et al. Essential hypertension, progressive renal disease, and uric acid: a pathogenetic link? J Am Soc Nephrol 2005; 16:1909.Baker JF, Krishnan E, Chen L, Schumacher HR. Serum uric acid and cardiovascular disease: recent developments, and where do they leave us? Am J Med 2005; 118:816.

It is unclear if hyperuricemia has a causal effect or, as has been more often suggested, is simply a marker for other risk factors, such as hypertension, dyslipidemia, and diabetes.

Culleton BF, Larson MG, Kannel WB, Levy D. Serum uric acid and risk for cardiovascular disease and death: the Framingham Heart Study. Ann Intern Med 1999; 131:7.Wannamethee SG, Shaper AG, Whincup PH. Serum urate and the risk of major coronary heart disease events. Heart 1997; 78:147.Wheeler JG, Juzwishin KD, Eiriksdottir G, et al. Serum uric acid and coronary heart disease in 9,458 incident cases and 155,084 controls: prospective study and meta-analysis. PLoS Med 2005; 2:e76.Feig DI, Kang DH, Johnson RJ. Uric acid and cardiovascular risk. N Engl J Med 2008; 359:1811.

VIPVValidity/Reliability; / ?I Importance/Impact; ?PPractice/Applicability; ?

Acquire

AppraisalApply

PICOAskingAccording to Sharon E. Straus et al, Evidence-based medicine: how to practice andteach EBM, Elsevier, 2005: 33-7. ValidityImportanceApplicabilityResults fromsecondarydatabaseResults fromprimarydatabaseAppraised byexpertsNeeded tobeappraisedResults(NNT)ResultsConsiderpopulationand feasibilityConsiderpopulationand feasibility

(Validity)RAM-bo(Randomized) (Accounted) (Measurement) (blind)(objective)(Intention-to-treat analysis, ITT)/ //()

(Importance/Impact)???(odds ratio) (relative risk)(absolute risk reduction) (relative risk reduction)(NNT, number needed to treat): NNT=1/ARR

(Practical , Applicability ?)1.(biological issues): --- ? -- 2.social and economic issues: -- -- 3.(epidemiological issues: -- -- --

4. / /

5.

?

1. (PICO)2. (PUB Med, Cochrane, Ovid)3. (Evidence level, Recommend grade) 4. ?

Case report () PICO () 5. 6.

Clinical question: Does gout cause a higher risk of stoke?

PICO type:TherapyPatient:Old patientIntervention:GoutComparison:Without goutOutcome:Risk of stroke

Title: Hyperuricemia and risk of stroke: a systematic review and meta-analysis.(2009)

Source:Arthritis Rheum. 2009 Jul 15;61(7):885-92

Level: 2a

1. : ()2. : 3. :4.

Thank You For Your Attention!

******