Skills for Evidence-Based Health Care Suzana Alves da Silva, MD, MSc, PhD Senior Researcher at the Health Technology Assessment Unit of Amil Assistência Médica Internacional S/A, Rio de Janeiro, Brazil

Conflict of interest None to declare

Suzana Silva, JECP 2010 “Knowledge does not extend from those who consider they know to those who consider they do not know. Knowledge is built in the relationship between human beings and perfects it self in the critical problematization of these relations.” Paulo Freire Scientifically Informed Medical Practice and Learning - SIMPLE Model

Circumstances Expertise Patients Evidence

Suzana Silva, JECP 2010 Problem Delineation “Knowledge does not extend from those who consider they know to those who consider they do not know. Knowledge is built in the relationship between human beings and perfects it self in the critical problematization of these relations.” Paulo Freire Scientifically Informed Medical Practice and Learning - SIMPLE Model

PROBLEM

Categories of problem

Categories of problems CategoriesTargetsDescription ProbabilityFrequency of outcomes over time of a condition PerformanceEffect of a characterisc on the risk of an outcome of a test on the presence of a condition UtilityMagnitude of the benefit offered of the harm caused

Actions and Choices will varie according to the domains of Therapy, Diagnosis, Prognosis and Harm Prognosis Probability Performance Utility What is the risk of AMI in 1 year in a asymptomatic pt with dislipidemia and calcium score of 100? For how many times this risk will be increased if this pt has diabetes and smokes? For how much the use of calcium score as a prognostic test decrease the risk of cardiovascular events in asymptomatic pt with dislipidemia?

Diagnosis Probability Performance Utility What is the pretest probability of coronary artery disease in a 40 y/o women with atypical chest pain? What is the test with best performance to investigate this patient? For how much the use of angiotomography to investigate CAD in patients like mine decrease the risk of cardiovascular events compared to other strategies? Actions and Choices will varie according to the domains of Therapy, Diagnosis, Prognosis and Harm

Analytical Framework DIAGNOSISHARM ProbabilityPerformanceUtilityProbability P 40 y/o female with atypical chest pain, with fears and priorities Patient wonders about AngioCT scan Health Managers Patient and physician wonders about safety A To assess the predictors: type of chest pain, age and sex AngioCT scan, TTest, Cintigraphy, Stress echo AngioCT scan C No alternative is available Coronariography TTest, Cintigraphy, Stress echo T Pre-test probability of coronary artery disease Accuracy of the tests Impact on cardiovascular events rate and costs Risk of cancer due to radiation exposure Risk of renal failure dure to contrast exposure

Analytical Framework DIAGNOSISHARM ProbabilityPerformanceUtilityProbability P 40 y/o female with atypical chest pain 40 y/o female with low to intermediate pre-test prob I Type of chest pain, age and sex AngioCT scan, TTest, Cintigraphy, Stress echo AngioCT scan C Coronariography TTest, Cintigraphy, Stress echo O Probability of coronary artery disease Accuracy of the tests Cardiovascular events rate and costs Cancer Renal failure

Types of information, study designs and sources

Suzana Silva and Peter Wyer. The Roadmap: a blueprint for evidence literacy within a Scientifically Informed Medical Practice and Learning model. The International Journal of Person Centered Medicine. In press. The TDS Evidence Pyramids Types of information Summaries Syntheses Single Studies Designs Guidelines Systematic Reviews Randomized and non randomized studies Sources Synopses Filtered Databases Large Biomedical Databases

DIAGNOSIS PROBABILITY Summary Synthesis Single Study CAD indicates coronary artery disease; and CASS, Coronary Artery Surgery Study. *Each value represents the percent with significant CAD on catheterization. Adapted from Forrester and Diamond Pretest Likelihood of CAD in Symptomatic Patients According to Age and Sex* (Combined Diamond/Forrester and CASS Data) Finh et al. ACCF/AHA/ACP Guideline on Stable Ischemic Heart Disease. JACC

Test Author, year SexSensitivitySpecificity + LR - LR Treadmill Test Morise and Diamond, 1995 M 0,96 (0,94-0,98) 0,40 (0,34-0,46) 10,00 (5,67-23) 0,63 (0,55-0,70) F 0,89 ( 0,85-0,93) 0,33 (0,25-0,41) 3,00 (1,67-5,86) 0,75 (0,63-0,88) SPECT Santana Boado, 1998 M 0,89 (0,67-0,99) 0,93 (0,87-0,98) 8,45 (2,64-98) 0,08 (0,02-0,19) F 0,91 (0,78-0,97) 0,85 (0,62-0,97) 9,44 (2,82-32,33) 0,16 (0,03-0,49) Multislice CT Mowat, 2008 T 0,87 (0,85-0,91) 0,96 (0,95-0,99) 7,38 (5,28-11) 0,05 (0,01-0,06) DIAGNOSIS PERFORMANCE Summary Synthesis Single Study

x Angio CTx AngioCT Mowat LR 9.5 -LR 0.05

x SPECT Angio CTx Cintigraphy Boado LR 7.5 -LR 0.16

x Treadmill Test Morise and Diamond LR 3.0 -LR 0.75

x if Test Result is + if Test Result is -

Can we trust these results?

Does the use of angiotomography compared to myocardium perfusion decreases the risk of cardiovascular outcomes?

Sheribati el al. Association of Coronary CT Angiography or Stress Testing with Subsequent Utilization and Spending Among Medicare Beneficiares. JAMA 2011 DIAGNOSIS UTILITY Summary Synthesis Single Study

What is the risk of cancer if this patient is submitted to radiation exposure?

HARM PROBABILITY Summary Synthesis Single Study Estimated Number of Patients Undergoing Computed Tomography (CT) That Would Lead to the Development of 1 Radiation-Induced Cancer, by Type of CT Examination and Age at the Time of Exposure, Based on the Median and Interquartile Radiation Dose Observed

Directness of evidence

Obrigada! Thank You!