Questions and outcomes


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Asking background and foreground questions, deciding on patient-oriented vs. disease-oriented outcomes

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  • Thank you for including a prognosis example - I have had such a hard time with this! Am borrowing to use for my library instruction for undergraduate evidence-based medicine.
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  • Love the negative examples. I think they really help clarify the nature of the questions. I'm borrowing that idea! Thank you.
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Questions and outcomes

  1. 1. Questions and Outcomes Self-Study Module John Epling, MD, MSEd Preventive Medicine Program SUNY-Upstate Medical University
  2. 2. Acknowledgements <ul><li>This presentation reviews material from: </li></ul><ul><ul><li>the Evidence-Based Medicine Working Group </li></ul></ul><ul><ul><ul><li> </li></ul></ul></ul><ul><ul><ul><li> </li></ul></ul></ul><ul><ul><li>the Information Mastery Working Group </li></ul></ul><ul><ul><ul><li> </li></ul></ul></ul>
  3. 3. Questions and Outcomes <ul><li>Two topics to start our course with: </li></ul><ul><ul><li>Clinical Questions </li></ul></ul><ul><ul><ul><li>How we know what we don’t know… </li></ul></ul></ul><ul><ul><li>Outcomes </li></ul></ul><ul><ul><ul><li>What are we striving for? </li></ul></ul></ul><ul><li>Click through these slides – there are definitions and examples for all the concepts. You’ll practice what you learned in class. </li></ul>
  4. 4. Clinical Questions <ul><li>Teach thy tongue to say 'I do not know,' and thou shalt progress. </li></ul><ul><ul><li>Maimonides </li></ul></ul>
  5. 5. Why talk about Questions? <ul><li>Because most of medical school is composed of asking YOU questions… </li></ul><ul><li>We don’t emphasize enough teaching you the reasons and ways to ask questions… </li></ul><ul><li>Questions help us be specific about how much and what we don’t know… </li></ul><ul><li>They can also help us efficiently fill our knowledge deficits… </li></ul>
  6. 6. Two types of Questions <ul><li>Background </li></ul><ul><li>Foreground </li></ul>
  7. 7. Background Questions <ul><li>Useful when you don’t have ANY knowledge about a topic </li></ul><ul><li>Non-focused, general knowledge questions </li></ul><ul><li>Think Stem + Clinical Topic </li></ul><ul><ul><li>Stem = What is, Why do, How does… </li></ul></ul><ul><ul><li>Clinical Topic – the disease/condition of interest </li></ul></ul>
  8. 8. Background Questions <ul><li>Examples: </li></ul><ul><ul><li>What is atrial fibrillation? </li></ul></ul><ul><ul><li>What are the causes of dyspnea? </li></ul></ul><ul><ul><li>What are the treatment options for deep vein thrombosis? </li></ul></ul><ul><li>NOT a Background Question: </li></ul><ul><ul><li>Should I use unfractionated heparin or low-molecular weight heparin for a patient with deep vein thrombosis? (too specific, comparing therapies) </li></ul></ul>
  9. 9. Foreground Questions <ul><li>Useful when you know about a topic, but you’re asking about a specific clinical comparison or test or detail about that topic. </li></ul><ul><li>Think: PICO </li></ul><ul><ul><li>P – patient/population </li></ul></ul><ul><ul><li>I – intervention/exposure/diagnostic test </li></ul></ul><ul><ul><li>C – comparison/no exposure/gold standard </li></ul></ul><ul><ul><li>O – outcome of interest/diagnosis </li></ul></ul>
  10. 10. Foreground Questions <ul><li>There are four main types of foreground questions: </li></ul><ul><ul><li>Therapy questions – comparing two or more interventions for a condition </li></ul></ul><ul><ul><li>Etiology/Harm – looking for an association between an exposure and an outcome </li></ul></ul><ul><ul><li>Diagnosis – comparing a new diagnostic test to the reference standard test </li></ul></ul><ul><ul><li>Prognosis – given a condition, does a certain factor portend a worse prognosis? </li></ul></ul>
  11. 11. Therapy Questions <ul><li>Example (Using the PICO format) </li></ul><ul><ul><li>In patients with deep vein thrombosis (DVT), does unfractionated heparin vs. low-molecular weight heparin lead to decreased recurrence of DVT? </li></ul></ul><ul><ul><ul><li>P – patients with DVT </li></ul></ul></ul><ul><ul><ul><li>I – unfractionated heparin </li></ul></ul></ul><ul><ul><ul><li>C – low molecular weight heparin </li></ul></ul></ul><ul><ul><ul><li>O – recurrence of DVT </li></ul></ul></ul>
  12. 12. Therapy Questions <ul><li>Example: </li></ul><ul><ul><li>In a population at risk for H1N1 influenza, does a new H1N1 vaccine (versus no vaccine) decrease disease rates? </li></ul></ul><ul><ul><li>In adults, does colorectal cancer screening (versus no screening) decrease mortality? </li></ul></ul><ul><li>NOT a Foreground Therapy Question: </li></ul><ul><ul><li>How is influenza treated in adults? (too broad, looking for treatment options, not comparing two or more for their effect on outcomes) </li></ul></ul>
  13. 13. Diagnostic Test Questions <ul><li>These compare the accuracy of a new diagnostic test with that of the “reference standard” (the true confirmatory test) for the condition. The outcome is the diagnosis . </li></ul><ul><li>Example (using PICO): </li></ul><ul><ul><li>In patients in whom acute appendicitis is suspected, does CT scan, as compared with exploratory laparotomy, diagnose appendicitis? </li></ul></ul><ul><ul><ul><li>P – pts with abdominal pain and poss appendicitis </li></ul></ul></ul><ul><ul><ul><li>I – CT scan </li></ul></ul></ul><ul><ul><ul><li>C – exploratory laparotomy (surgery, the reference standard) </li></ul></ul></ul><ul><ul><ul><li>O – diagnosis of appendicitis </li></ul></ul></ul>
  14. 14. Diagnostic Test Questions <ul><li>Example: </li></ul><ul><ul><li>In patients with a history of recent chest pains, does stress echocardiography versus cardiac catheterization diagnose coronary artery disease? </li></ul></ul><ul><li>NOT a diagnostic test question: </li></ul><ul><ul><li>In patients presenting to the ED with dyspnea, does the use of a beta-natriuretic peptide test result in decreased morbidity and hospital stay? </li></ul></ul><ul><ul><li>(tricky, the question is about a diagnostic test, but it is about how the use of the test alters clinical outcomes…not how well it diagnoses the disease) </li></ul></ul>
  15. 15. Etiology/Harm Questions <ul><li>Useful to determine if one or more risk factors/exposures makes a clinical outcome more likely. </li></ul><ul><li>Example with PICO: </li></ul><ul><ul><li>In adults, does cell phone use (versus no cell phone use) increase the risk of brain cancer? </li></ul></ul><ul><ul><ul><li>P – adults </li></ul></ul></ul><ul><ul><ul><li>I – cell phone use (exposure…you may want to define a certain amount of exposure as qualifying </li></ul></ul></ul><ul><ul><ul><li>C – no cell phone use (or below the certain amount) </li></ul></ul></ul><ul><ul><ul><li>O – brain cancer rates </li></ul></ul></ul>
  16. 16. Etiology/Harm Questions <ul><li>Example: In previously healthy children, does vaccination with MMR vaccine increase the risk of autism? </li></ul><ul><li>Example: In adults with high risk of coronary heart disease, does exposure to vitamin E reduce the risk of coronary events? </li></ul><ul><li>NOT an etiology question: What are the causes of autism? (too broad…although several etiology questions might provide the evidence to answer this some day) </li></ul>
  17. 17. Prognosis Questions <ul><li>Useful to determine which factors change the prognosis of a given disease. </li></ul><ul><li>Example (using PICO): In patients with diabetes, does the development of neuropathy portend a greater mortality risk? </li></ul><ul><ul><li>P - patients with type 2 diabetes, </li></ul></ul><ul><ul><li>I – development of neuropathy </li></ul></ul><ul><ul><li>C – not developing neuropathy </li></ul></ul><ul><ul><li>O –greater risk of mortality </li></ul></ul>
  18. 18. Prognosis Question <ul><li>Examples: In patients with coronary heart disease, does an episode of CHF lead to reduced overall quality of life? </li></ul><ul><li>NOT a prognosis question: </li></ul><ul><ul><li>In diabetics, does smoking lead to a greater risk of neuropathy? </li></ul></ul><ul><ul><li>(while the difference between harm and prognosis questions is sometimes slight, this is really asking about a risk factor rather than a clinical development) </li></ul></ul>
  19. 19. Questions about Questions? <ul><li>There you have it. </li></ul><ul><li>Background Questions – used when you need a general review of a given topic. </li></ul><ul><ul><li>They’re best answered with review articles from trustworthy sources (we’ll talk about this later) </li></ul></ul><ul><li>Foreground Questions – used when you have a focused, clinical question </li></ul><ul><ul><li>Look to original research (or structured synopses of original research) for these answers (we’ll talk about these later too!) </li></ul></ul>
  20. 20. Quick Break! <ul><li>Get up and stretch, get that second (or seventh) cup of Starbucks™, and then press on! </li></ul>
  21. 21. Outcomes <ul><li>All studies have outcomes…That’s what the study authors want to see change in as a result of the intervention or the exposure. </li></ul><ul><li>Outcomes can be any definable clinical condition – a lab test result, a diagnosis, reaction or opinion, life or death, etc. </li></ul>
  22. 22. Outcomes <ul><li>For our purposes, we can divide outcomes into those that are PATIENT-ORIENTED and those that are DISEASE-ORIENTED. </li></ul><ul><li>Patient-Oriented – these are outcomes that patients can identify with: life/death, sickness events (heart attacks, strokes), hospitalizations, disability, symptom rates, etc. </li></ul><ul><li>Disease-Oriented – everything else – especially numbers – HgbA1c or lipid levels, blood pressure numbers. </li></ul>
  23. 23. Outcomes <ul><li>Frequently, in research, we look for “proxy measures” of disease – if we can prove that a high blood pressure is associated with mortality, then we can assume that lowering that blood pressure will reduce mortality. </li></ul><ul><li>That just ain’t necessarily so – the body is complex, our interventions have side effects and there may be unintended consequences. </li></ul>
  24. 24. Outcomes <ul><li>Examples of proxy outcomes that failed: </li></ul><ul><ul><li>CAST – we assumed that treating ventricular dysrhythmia after a heart attack was a good thing…but the treatment was worse than the disease . </li></ul></ul><ul><ul><li>Womens’ Health Intiative – we improved cholesterol, bone density and possibly Alzheimer’s with estrogen in post-menopausal women, but not until the better trial was performed did we realize we were causing disease . </li></ul></ul>
  25. 25. Outcomes <ul><li>So, we, as busy clinicians, should try to find all the Patient-Oriented Evidence we can. By doing so, we can avoid hasty or premature conclusions about how the body and our treatments work. </li></ul><ul><li>When faced with Disease-Oriented Evidence, we must use caution in interpreting its results, and look for more Patient-Oriented results (elsewhere in the literature, or in the future from better studies) </li></ul>
  26. 26. Outcomes <ul><li>When we’re evaluating the medical literature, outcomes aren’t the only important criteria, but focusing on Patient-Oriented outcomes can help us avoid overtreating based on preliminary findings. </li></ul>