5. Most of your questions Which is better to treat, drug A or drug B? Which is better to treat, oral or IV? Which is better to treat, chemo or radio?
6. Class Activity 10 minutes A group of 5 You are a group of researchers. You want to know which is better drug A or drug B in treating patients with hospital-acquired pneumonia in terms of hospital stay How would you do that? Suggest a research design plan
8. Case Report A descriptive study of one patient Detailed profile of a “rare” presentation or treatment Helpful in developing hypothesis to be tested later using analytic study
9. Case Series A descriptive study of multiple patients “Rare” phenomenon occurring multiple times Detailed profile of patients’ presentation and outcome Helpful in developing hypothesis
10. Disadvantages ofCase Report & Case Series Retrospective (looking back in time) Selection bias Recall bias Small sample size That’s why at the bottom of the pyramid
11. Case-Control Studies(for risk factors) Cases (e.g., Lung Cancer) Shisha Smokers GO BACK IN TIME NOT Shisha Smokers Ask patients Read files Control (e.g., Lung Cancer) Shisha Smokers GO BACK IN TIME NOT Shisha Smokers
12. Problems with Case-Control Studies Looking back in time (retrospective) Recall bias Measurement bias You may miss important risk factors
13. Cohort Study Cohort: Roman word for “a group of soldiers that marched into battle together” A group of people followed up with time to see whether an outcome of interest develops Prospective or Retrospective
14. Prospective Cohort Shisha Smokers Lung Cancer F/U No Lung Cancer NOT Shisha Smokers Lung Cancer F/U No Lung Cancer
15. Cohort Study Prospective or Retrospective Drawbacks: Large number of patients Follow them up for long time
17. Why RCT is the highest level of evidence? Randomization: balance known and unknown prognostic factors Blinding: Patients Researchers Outcome assessors Aim for complete follow-up
18. Primary Sources Case report Case series Case-control Cohort Randomized controlled trial
19. Not all studies are good quality After you asked the PICO question You need to find the information (ACQUIRE) Then, you need to “APPRAISE” the quality of each relevant study you find
21. Searching for evidence Case report, Case series, Case-Control, Cohort, Randomized Trial DiCenso A, Bayley L, Haynes RB. Accessing preappraised evidence: fine-tuning the 5S model into a 6S model. ACP Journal Club, 2009
22. Systematic Review Ask a research question (PICO) Set up the studies inclusion & exclusion criteria Literature search: Systematically & thoroughly Keywords & MeSH terms Multiple databases & multiple sources Select the studies & assess their quality Summarize the findings Done in a pair
23. Meta-analysis All the previous steps Statistical pooling of the results of all studies
24. Searching for evidence Secondary Primary Case report, Case series, Case-Control, Cohort, Randomized Trial DiCenso A, Bayley L, Haynes RB. Accessing preappraised evidence: fine-tuning the 5S model into a 6S model. ACP Journal Club, 2009
25. The Usefulness Equation Usefulness = Relevance x Validity of any source Work Shaughnessy AF, Slawson DC, Bennett JH. Becoming an Information Master: A Guidebook to the Medical Information Jungle. The Journal of Family Practice 1994;39(5):489-99.
26. Relevance: Type of Evidence POE: Patient-oriented evidence mortality, morbidity, quality of life Live longer and/or better DOE: Disease-oriented evidence pathophysiology, pharmacology, etiology Shaughnessy AF, Slawson DC, Bennett JH. Becoming an Information Master: A Guidebook to the Medical Information Jungle. The Journal of Family Practice 1994;39(5):489-99.
27. Validity The hard part of Information Mastery Technique: EBM working group Guyatt G, Rennie D, ed. Users’ guides to the medical literature. A manual for evidence-based clinical practice. Chicago: AMA, 2002. Did the researchers find what they think they found? Do the results apply to your patients? Self vs delegation- Take responsibility
28. Work Not all information sources are created equal Two type of information sources “Just-in-case” sources: high work “Just-in-time” sources: low work
30. Terms We Talked about Today POE versus DOE Primary Sources versus Secondary Sources Primary: Case report, Case series, Case-Control, Cohort Study, Randomized controlled trial Secondary: Systematic reviews, Synopses, Summary, Systems
Editor's Notes
An observational studyCompare two groups: CASES: a group with the outcome of interest (e.g., non-healed fractures)CONTROLS: a similar group without the outcome of interest (e.g., healed fractures)Determine how many patients within each group have the risk factor (e.g., smoking Shisha)
An observational studyYou follow a group of people with certain risk factors and another group without these risk factorsYou follow them for a period of time and look for the outcome of interest
