BECOMING AN INFORMATION MASTER-or-

1. BECOMING AN INFORMATION MASTER-or- How to feel good about not knowing everything

2. AGENDA • Context and some philosophy • Learn what is: ‘patient-oriented’ evidence • Asking clinical questions • Look at a couple examples from therapy articles • Learn to calculate some things • Practice calculating some things • Learn what the numbers mean for practice • If time, some searching

3. EVIDENCE BASED MEDICINE The judicious and conscientious use of current best evidence from medical care research in making decision about the care of individuals.

4. DEFINITION FOR THE 21ST CENTURY • a set of tools and resources for finding and applying current best evidence from research for the care of individual patients. • “evidence based medicine seeks to empower clinicians so that they can develop independent views regarding medical claims and controversies”

5. The Problem • “In family medicine it was recently estimated that a physician would need to spend 627.5 hours just to read the 7287 articles relevant to primary care published each month”

6. HOW DO WE MAKE CLINICAL DECISIONS? Clinical expertise Patient’s preferences Research Evidence

7. The bigger picture • More health care does NOT equal more health • Diminishing returns on health care spending beyond $1000/capita/year • How much does Canada spend? • How likely is a BP patient in family medicine to be on a thiazide diuretic ($) compared to ACE-I in a specialist setting ($$$)?

8. APPLICATION OF EBM TO PRIMARY CARE • Review of the literature on patient centered care: • Patient satisfaction is the highest when they take part fully in decision making • Patient compliance with the strategy is better when the decision has been made in partnership

9. APPLICATION OF EBM TO PRIMARY CARE Clinical Expertise (I.e. Parachute prevents death!!) There will never be an RCT to prove that Pap screening reduced cervical cancer or that cigarette smoking causes lung cancer

10. Patient-oriented evidence? Anti-depressants may benefit some patients with inflammatory bowel disease by Suzanne MorrisonMay 02, 2008 VS Acarbose in the prevention of cardiovascular disease and hypertension in patients with impaired glucose tolerance

11. THE WELL BUILT CLINICAL QUESTION • Anatomy of a question: PICO P- What is the type of patient or problem to be addressed I- What is the intervention or exposure being considered? C- What is the comparison intervention or exposure (if relevant) O- What are the clinical outcomes of interest

12. Acarbose in the prevention of cardiovascular disease and hypertension in patients with impaired glucose tolerance Example of a POEM (CMA) • Level of evidence = A • Acarbose is effective in the prevention of cardiovascular events and hypertension in patients with impaired glucose tolerance. • In an international, multicentre trial 1, 1429 patients with a mean age of 54.5 years and BMI 30.9 were randomized to receive either acarbose 100 mg 3 times a day or placebo. Decreasing prostprandial hyperglycemia with acarbose was associated with a 2.5% absolute risk reduction and a 49% relative risk reduction in the development of cardiovascular events (HR 0.51, 95% CI 0.28 to 0.95), and a 5.3% absolute risk reduction and 34% relative risk reduction in the incidence of new cases of hypertension (HR 0.66, 95% CI 0.49 to 0.89). The risk reduction was no influenced by adjusting for major risk factors. • References • Chiasson JL, Josse RG, Gomis R, Karasik A, Laakso M, for the STOP-NIDDM Trial Research Group. Acarbose treatment and the risk of cardiovascular disease and hypertension in patients with impaired glucose tolerance. JAMA 2003;290:486-494

13. What did those numbers mean in practice? Consider a study in which 15% (0.15) of the control group and 10% (0.10) of the treatment group died after 2 years of treatment. The results can be expressed in many ways as shown below.

19. Let’s do an example on the board

20. What are the numbers for our example? Patients Understand pictures better than RRR, NNT

21. Knowing how to use your time wisely

23. Look at literature similar to a Drug Rep • Pharmaceutical "reps" are now much more informative than they used to be, but they may show ignorance of basic epidemiology and clinical trial design • The value of a drug should be expressed in terms of safety, tolerability, efficacy, and price • The efficacy of a drug should ideally be measured in terms of clinical end points that are relevant to patients; if surrogate end points are used they should be valid • Promotional literature of low scientific validity (such as uncontrolled before and after trials) should not be allowed to influence practice

24. identify, for this patient, the ultimate objective of treatment(cure, prevention of recurrence, limitation of functional disability,prevention of later complications, reassurance, palliation,relief of symptoms, etc); • select the most appropriate treatment,using all available evidence(this includes considering whetherthe patient needs to takeany drug at all); and • specify thetreatment target (to know when to stop treatment,change itsintensity, or switch to some other treatment).

26. E.g. hypertension • the ultimate objective of treatment is to prevent (further)target organ damage to brain, eye, heart, kidney, etc (and therebyprevent death); • the choice of specific treatment is betweenthe various classesof antihypertensive drug selected on thebasis of randomised,placebo controlled and comitemtive trials—aswell as non-drugtreatments such as salt restriction; and • thetreatment target might be a phase V diastolic blood pressure(right arm, sitting) of less than 90 mm Hg, or as close to thatas tolerable in the face of drug side effects.

27. Good surrogate endpoint • The surrogate end point should be reliable, reproducible, clinically available, easily quantifiable, affordable, and show a "dose-response" effect (the higher the level of the surrogate end point, the greater the probability of disease) • It should be a true predictor of disease (or risk of disease). The relation between the surrogate end point and the disease should have a biologically plausible explanation • It should be sensitive—a "positive" result in the surrogate end point should pick up all or most patients at increased risk of adverse outcome • It should be specific—a "negative" result should exclude all or most of those without increased risk of adverse outcome • There should be a precise cut off between normal and abnormal values • It should have an acceptable positive predictive value—a "positive" result should indicate a high likelihood of the outcome

28. Database searching for evidence

29. Pubmed clinical queries (single articles, specific) • Health Knowledge Central (general site compiling other resources) • Cochrane database (high quality for therapy but not many topics) • Bandolier (critically appraised for you) • E-medicine • Up to date

30. Search questions? • Treatment of subclinical hypothyroidism? • 42 year old patient with sudden onset of severe hypertension refractory to treatment. - Who should be screened for secondary causes of hypertension? • 60 year old woman with ‘squeezing’ chest pain, controlled hypertension- is an ECG useful to determine need to go to ER?