Evidence Based EMS


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This is a lecture I wrote to introduce my students to the concept of Evidence Based medicine. Goes hand in hand with many handouts, such as the parachute study.

Special thanks to Dr. Brian Bledsoes lecture on EBM, from wich I pirated liberally.

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  • Definition of RESEARCH1: careful or diligent search2: studious inquiry or examination; especially : investigation or experimentation aimed at the discovery and interpretation of facts, revision of accepted theories or laws in the light of new facts, or practical application of such new or revised theories or laws3: the collecting of information about a particular subject See research defined for English-language learners »See research defined for kids »Examples of RESEARCHShe conducts research into the causes of Alzheimer's disease.Recent research shows that the disease is caused in part by bad nutrition.The study is an important piece of research.He did a lot of research before buying his car.Origin of RESEARCHMiddle French recerche, from recercher to go about seeking, from Old French recerchier, from re- + cerchier, sercher to search — more at searchFirst Known Use: 1577
  • Definition of SCIENCE1: the state of knowing : knowledge as distinguished fromignorance or misunderstanding2a : a department of systematized knowledge as an object of study <the science of theology>b : something (as a sport or technique) that may be studied or learned like systematized knowledge <have it down to ascience>3a : knowledge or a system of knowledge covering general truths or the operation of general laws especially as obtained and tested through scientific methodb : such knowledge or such a system of knowledge concerned with the physical world and its phenomena :natural science4: a system or method reconciling practical ends with scientificlaws <cooking is both a science and an art>
  • Definition of EVIDENCE1a : an outward sign : indicationb : something that furnishes proof : testimony; specifically :something legally submitted to a tribunal to ascertain the truth of a matter2: one who bears witness; especially : one who voluntarily confesses a crime and testifies for the prosecution against his accomplices— in evidence1: to be seen : conspicuous <trim lawns … are everywhere in evidence — American Guide Series: North Carolina>2: as evidence See evidence defined for English-language learners »See evidence defined for kids »Examples of EVIDENCEThere is no evidence that these devices actually work.He has been unable to find evidence to support his theory.Investigators could find no evidence linking him to the crime.The jury had a great deal of evidence to sort through before reaching a verdict.There is not a scrap of evidence in her favor.Anything you say may be used as evidence against you.
  • Evidence-based medicine (EBM), also called evidence-based health care (EBHC) or Evidence-based practice (EBP) to broaden its application to allied health care professionals, has been defined as "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients."[1][2] Trisha Greenhalgh and Anna Donald define it more specifically as "the use of mathematical estimates of the risk of benefit and harm, derived from high-quality research on population samples, to inform clinical decision-making in the diagnosis, investigation or management of individual patients."[3]EBM seeks to assess the strength of the evidence of risks and benefits of treatments (including lack of treatment) and diagnostic tests.[4] This helps clinicians predict whether a treatment will do more good than harm.[5]Evidence quality can be assessed based on the source type (from meta-analyses and systematic reviews of triple-blind randomized clinical trials with concealment of allocation and no attrition at the top end, down to conventional wisdom at the bottom), as well as other factors including statistical validity, clinical relevance, currency, and peer-review acceptance. EBM recognizes that many aspects of health care depend on individual factors such as quality- and value-of-life judgments, which are only partially subject to quantitative scientific methods. Application of EBM data therefore depends on patient circumstances and preferences, and medical treatment remains subject to input from personal, political, philosophical, religious, ethical, economic, and aesthetic values.
  • “Practicing at the level of graduation”: Many providers practiced based on the expectations and standards in place at the time of entering practice/graduating from school….clinging to their comfort zone even after standards and expectations evolved.Early 1970’s: Destroying the assumptionDocumentation of wide variation in practice patterns (Wennberg, 1973)Dramatic procedural variation (RAND)Most medical practice was founded on tradition/experience rather than evidence.Cochrane-1972: Many standards of care were found to be ineffective…or even dangerous. IOM Report-1985: Estimate: Only 15% of medical practices based upon solid evidence. Enormous lag-time from new research findings to practice.Dutton-1988: “Worse than the Disease: Pitfalls of Medical Progress.”
  • Discussion on how what happens in controlled research conditions with carefully selected patients does not always translate to the bedside.
  • Evidence based medicine is not "cookbook" medicine. Because it requires a bottom up approach that integrates the best externalevidence with individual clinical expertise and patients' choice, it cannot result in slavish, cookbook approaches to individualpatientcare. External clinical evidence can inform, but cannever replace, individual clinical expertise, and it is thisexpertise that decides whether the external evidence appliesto the individual patient at all and, if so, how it should be integrated into a clinical decision. Similarly, any externalguideline must be integrated with individual clinical expertiseindeciding whether and how it matches the patient's clinicalstate, predicament, and preferences, and thus whether it shouldbe applied. Clinicians who fear top down cookbooks will findthe advocates of evidence based medicine joining them at thebarricades.
  • External clinical evidence can inform, but cannever replace, individual clinical expertise, and it is thisexpertise that decides whether the external evidence appliesto the individual patient at all and, if so, how it should be integrated into a clinical decision.
  • Evidence based medicine is the conscientious, explicit, andjudicious use of current best evidence in making decisions aboutthe care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise withthe best available external clinical evidence from systematicresearch. By individual clinical expertise we mean the proficiencyand judgment that individual clinicians acquire through clinicalexperience and clinical practice. Increased expertise is reflectedin many ways, but especially in more effective and efficientdiagnosis and in the more thoughtful identification and compassionateuse of individual patients' predicaments, rights, and preferencesin making clinical decisions about their care. By best availableexternalclinical evidence we mean clinically relevant research,often from the basic sciences of medicine, but especially frompatientcentred clinical research into the accuracy and precisionof diagnostic tests (including the clinical examination), thepower of prognostic markers, and the efficacy and safety oftherapeutic, rehabilitative, and preventive regimens. Externalclinical evidence both invalidates previously accepted diagnostictestsand treatments and replaces them with new ones that are more powerful, more accurate, more efficacious, and safer.
  • One does not have to believe a given researcher, one can redo the experiment and determine whether his or her results are true or false. The conclusions will hold irrespective of the state of mind, or the religious persuasion, or the state of consciousness of the investigator and/or the subject of the investigation. It focuses on the results of the science, regardless of what they show.It assumes that its conclusions may one day be disproven by new science, and that is OK (after all , that is science)
  • Determine that you will declare two days before and two days after the full moon a five-day “full moon period.”Gather information over the course of the year that includes the date of all psychiatric emergency patients.When the data has been gathered for the period previously determined, you determine:1. How many psychiatric patients were there?2. How many were treated during the full moon periods?
  • External Validity: The extent and appropriateness of the generalizability of results.Internal Validity: The basic minimum control, measure, analysis and procedures necessary to make results interpretable.
  • AHA Classes of Recommendations and Levelsof EvidenceGenerally for Class I recommendations, high-level prospectivestudies support the action or therapy, and the benefitsubstantially outweighs the potential for harm. An exceptionis possible for actions or therapies with extraordinarily largetreatment effects for which expert consensus alone maysuffice.11 Under ideal conditions all CPR and ECC recommendationsshould be based on large, prospective, randomized,controlled clinical trials that find substantial treatmenteffects on long-term survival and carry a Class I label. Inreality, more questions exist than there are studies attemptingto answer them; and when studies have been done, they arenot typically large, randomized trials on human subjects. Asa result, the writing groups were often confronted with theneed to make recommendations based on results from humantrials that reported only intermediate outcomes, nonrandomizedor retrospective observational studies, animal models, orextrapolations from studies of human subjects who were notin cardiac arrest.For Class IIa recommendations, the weight of availableevidence supports the action or therapy, and the therapy isconsidered reasonable and generally useful. Recommendationswere generally labeled Class IIb when the evidence documentedonly short-term benefits from the therapy or weakly positive ormixed results. Class IIb recommendations are identified by termssuch as “can be considered” or “may be useful” or “usefulness/effectiveness is unknown or unclear or not well established.”Class III recommendations were reserved for interventionsfor which the available evidence suggests more harm thangood, and experts agreed that the intervention should beavoided.“Class Indeterminate” recommendations, which were usedin 2005, are not included in the 2010 AHA Guidelines forCPR and ECC. The elimination of the term “Class Indeterminate”is consistent with the ACCF–AHA Classes of Recommendation.When the AHA writing groups felt that theevidence was insufficient to offer a recommendation eitherfor or against the use of a drug or intervention, no recommendationwas given.
  • *Data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as gender, age, history of diabetes, history of priormyocardial infarction, history of heart failure, and prior aspirin use. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak.Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Even though randomized trials are not available, there may be a very clear clinical consensus that a particular test or therapy is useful or effective.†In 2003, the ACCF/AHA Task Force on Practice Guidelines developed a list of suggested phrases to use when writing recommendations. All guideline recommendations have been written in full sentences that express a complete thought, such that a recommendation, even if separated and presented apart from the rest of the document (including headings above sets of recommendations), would still convey the full intent of the recommendation. It is hoped that this will increase readers’ comprehension of the guidelines and will allow queries at the individual recommendation level.
  • When should a stand be taken that clearly states that insufficient evidence exists…and that a guideline is inappropriate? i.e. BackBoardingOr what if a guideline is appropriate, but there is no evidence? (I.E. Lidocaine)What if there are already LOTS of guidelines out there?Are there interventions that should be “trashed” despite their wide-spread use? If CONSENSU Sis the basis for a guideline, how is this distinguishable from EVIDENCE-based guidelines?What are the implications of having these guidelines LOOK equally authoritative when they make it to the street?
  • Evidence Based EMS

    1. 1. Evidence Based EMS2013 Advanced EMT Course
    2. 2. Definitions
    3. 3. Definitions: Research• Research: noun ri-ˈsərch, ˈrē-ˈ• 1 : careful or diligent search• 2 : studious inquiry or examination;• especially : investigation orexperimentation aimed at the discoveryand interpretation of facts, revision ofaccepted theories or laws in the light ofnew facts, or practical application ofsuch new or revised theories or laws• 3 : the collecting of informationabout a particular subject
    4. 4. Definitions: Science• Science: noun ˈsī-ən(t)s• 1 : the state of knowing : knowledge as distinguished from ignorance ormisunderstanding• 2 a department of systematized knowledge as an object ofstudy <the science of theology>• 3 knowledge or a system of knowledge covering general truths or theoperation of general laws especially as obtained and tested through scientificmethod• b such knowledge or such a system of knowledge concerned with the physical world andits phenomena - i.e. natural science• 4 : a system or method reconciling practical ends with scientific laws• “cooking is both a science and an art”
    5. 5. “Science is neither a philosophy nor a belief system. It isa combination of mental operations that has becomeincreasingly the habit of educated peoples, a culture ofilluminations hit upon by a fortunate turn of history thatyielded the most effective way of learning about the realworld ever conceived.”Edward O. WilsonConsilience: The Unity ofKnowledgeSo then, what is Science?
    6. 6. Definition: Evidence• Evidence: noun ˈe-və-dən(t)s, -və-ˈden(t)s• 1 : an outward sign• 2 : something that furnishes proof :• specifically :something legally submitted to a tribunal to ascertain the truth ofa matter• 3: to be seen
    7. 7. Definitions: Evidence Based Medicine(EBM)• “ “…The conscientious, explicit and judicious use of current bestevidence in making decisions about the care of individual patients.”• Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS (January1996). "Evidence based medicine: what it is and what it isnt". BMJ 312 (7023): 71–2.PMC 2349778. PMID 8555924.• “…The use of mathematical estimates of the risk of benefit and harm,derived from high-quality research on population samples, to informclinical decision-making in the diagnosis, investigation ormanagement of individual patients.“• Greenhalgh, Trisha. How To Read a Paper: The Basics of Evidence-Based Medicine. Wiley-Blackwell, fourth edition, 2010, p. 1.
    8. 8. Background: Why EBM?• Prior to the 1970’s, it was assumed that basic medical education,clinical updates, and interaction with other providers was adequate toguide good decision making.• Research in the 1970’s found HUGE variance on how providers wouldtreat similar clinical conditions.• Most patient care was based on tradition and/or experience rather thanevidence and research
    9. 9. Background: Why EBM?• Most patient care was based on tradition and/or experience ratherthan evidence and research• “That’s the way we always did it, why change”• “Practicing at the level of graduation”• Institute of Medicine (IOM) Report-1985 Estimate: Only 15% ofmedical practices based upon solid evidence.• Probably much much less for EMS
    11. 11. EBM: What it is…• A means to take individual biases and common cognitive errors out ofthe equation• A means to keep up to date and evolve as the art and science ofmedicine evolves.• A means to apply a rigorous review to what we previously justaccepted as truth.
    12. 12. EBM: What it isnt• “Cook-book” medicine• Tends to require more thinking to apply it correctly• “Cost-cutting” medicine• Sometimes the cost of care will increase, though the effectiveness will also(More bang for the buck)• A replacement for clinical expertise• A replacement for common sense• Absolute rules and regulations that leave no room for deviation
    13. 13. KEY POINT:• External clinical evidence can inform, but can never replace,individual clinical expertise…..
    14. 14. EBM:• The practice of evidence based medicine means integratingindividual clinical expertise with the best available external clinicalevidence from systematic research.• “Individual Clinical Expertise”: What does this mean?• The proficiency and judgment that individual clinicians acquire throughclinical experience and clinical practice• Typically acquired over years (decades?) of actual practice….• “Best Available Clinical Evidence”: What does this mean?• clinically relevant research, often from the basic sciences of medicine, butespecially from patient centered clinical
    15. 15. EBM: Focus• Focuses on:• Accuracy of diagnostic tests including the clinical examination.• Example: 80-70-60 Rule of blood pressure, 12 rhythm interpretation• The power of prognostic markers,• Example: Glascow Coma Scale, Trauma levels, Mechanism of Injury /Co-Morbid factors• The efficacy and safety of therapeutic, rehabilitative, and preventiveregimens.• MAST Pants• Intubation
    16. 16. What does this mean to me?• Good Medics/EMTs use both individual clinical expertise and the bestavailable external evidence, and neither alone is enough.• Without clinical expertise, protocols risks becoming tyrannised byevidence, becoming Cook Book medicine.• Even excellent external evidence may be inapplicable to orinappropriate for an individual patient.• Without current best evidence, practice risks becoming rapidly out ofdate, to the detriment of patients
    17. 17. Art or Science?• Some health practices are moreabout art than science.• Chiropractic, for example, haslittle science and a lot of art.• Neurology today has a great dealof science and little art.• Have you ever met a neurosurgeonwith personality?
    18. 18. Art or Science?• Neurology today has a great dealof science and little art.
    19. 19. Is EMS Art or Science?• The knowledge of EMS is science.• The way it is applied is art.• Excellent EMTs know the scienceof EMS and use the art of EMS toapply the science.
    20. 20. “…Medicine is an Art, masquerading as a science”Robert. S. Cole, NR-P, OCD, Resident Weirdo
    21. 21. Art or Science?• When you have a life threateningillness or injury, would you seekout a health care provider whosepractice was more art or morescience?
    22. 22. Art or Science?• EMS is the safety net of society.• We are often the first to providecare to the injured and the infirm.• Our practices must be based onscience.
    23. 23. But we must apply them with art!
    24. 24. Understanding the Research……
    25. 25. Understanding the Research• EBM is based n research…• To appropriately apply EBM, you must understand the research it isbased on, so you can apply it correctly…..• Most research is based on the “Scientific Method”
    26. 26. The Scientific Method
    27. 27. The Scientific Method• The great advantage of the scientific method is that it is unprejudiced.• Scientific research is reproducible• One does not have to believe a given researcher, one can redo the experiment anddetermine whether his or her results are true or false.• Scientific Research is unbiased• The conclusions will hold irrespective of the state of mind, or the religious persuasion, orthe state of consciousness of the investigator and/or the subject of the investigation.• It focuses on the results of the science, regardless of what they show.• Scientific Research evolves as our understanding evolves• It assumes that its conclusions may one day be disproven by new science, and that is OK(after all , that is science)
    28. 28. ObservationHypothesisPredictionsTheory/ Empirical LawExperiment
    29. 29. The Scientific Method: The Theory/Empiracal Law• A theory is accepted not based on the prestige or convincing powersof the proponent, but on the results obtained through observationsand/or experiments which anyone can reproduce.• In other words: the theory is not based on the credentials of thescientists, rather on the strength and reproducibility of the theoryitself…
    30. 30. The Scientific Method: Observation• Observation: During a discussion you and your coworkers bring up the idea thatthere are more psychiatric emergencies when the moon is full.
    31. 31. The Scientific Method: Predictions• Prediction: You predict that there will be more EMS calls for psychiatricemergencies when the moon is full as compared to other times of the month.
    32. 32. The Scientific Method: The Experiment• You need a study group and a control group…
    33. 33. The Scientific Method: The Hypothosis• Hypothesis: Psychiatric emergencies are more common when the lunar cycle is inthe full moon phase.
    34. 34. The Scientific Method: Experiment• Testing: You set up an experimental protocol to test your hypothesis.• You need:• A study method• A study period• Study Parameters• A study group• A control group
    35. 35. The Scientific Method: Experiment• A study method• You decide that you will review charts (AKA a retrospective review)• A study period• You decide to review the charts for a period of a year• Study Parameters• You will review all charts over the period• You will define the term “Psychiatric Emergency”• You will gather information over the course of the year that includes the date of all psychiatricemergency patients.• A study group• Al patients that occur in your “Full Moon Period”• Define “full Moon Period” as 2 days before and after a full moon.• A control group• All other patient contacts outside of your full moon period….
    36. 36. The Scientific Method: The ExperimentResults:Full Moon PeriodDays=65Other PeriodDays = 300TotalDays = 365Ψ patients = 10 Ψ patients = 74 Total Ψ patients = 84Total Patients =2,105Total Patients = 9,300 Total Patients = 11,315
    37. 37. The Scientific Method: The Experiment• Use of the scientific method in EMS.• Results: Your study finds:• During full moon period 0.5% of patients were Ψ patients.• During other period 0.8% of patients were Ψ patients.• During the entire study period 0.7% of patients were Ψ patients.
    38. 38. The Scientific Method: The Experiment• Use of the scientific method in EMS.• Results: Your study finds:• The incidence of Ψ patients during the full moon period was 0.15 patients per day.• The incidence of Ψ patients during the other moon phases was 0.25 patients perday.• The incidence of Ψ patients overall was 0.23 patients per day.• What does this mean?????• Psych patients are less common during the full moon.• HYPOTHESIS DISSPROVED!• What Your Hypothesis didn’t work out? That’s ok, because its SCIENCE, and the result is what counts , notour assumptions going into the experiment….• SO , now what do you do?
    39. 39. Answer: You change your hypothesis tomatch your results(unless you are a drug company, then you do it the other wayaround….)• Revise hypothesis:• New hypothesis: Psychiatric emergencies are no more frequent during fullmoon lunar phases than during other lunar phases.• Based on research, this HYPOTHESIS is now ACCURATE (until disproven)
    40. 40. Now what do you do with your new andproven/researched hypothesis?• 1- TELL PEOPLE SO THEY CAN BENEFIT!• Report findings. Paper should be detailed enough that anybody can follow itand repeat your experiment in their own enviroment• 2- Repeat study to determine whether findings can be repeated.• i.e. does your study hold true in other systems?• Are there any weakness in your study you can correct, and then avoid in anew study?
    41. 41. EMS Research• The more valid a study, the closerit is to the truth!
    42. 42. EMS Research• Bias:• A mental leaning or inclination; partiality; prejudice; bent.• The more a study design adheres to the scientific method, the less chance forbias to affect the outcomes.
    43. 43. EMS Research• Bias (sometimes flat deception)has been a common practice inmedicine and EMS.• Quackery and bias still permeatesmany aspects of modernhealthcare.
    44. 44. EMS Research• Validity:• Whether the study measures what it was supposed to measure.• Validity refers to the appropriateness of the interpretation of the results of a study.• Constant:• A characteristic or condition that is the same for all individuals in a study.• Variable:• A characteristic that takes on different values or conditions for different individuals.• Dependent Variable: the variable being affected or assumed to be affected my theindependent variable.• Independent Variables: the variables that affects (or is assumed to affect) the dependentvariable under study.• Experimental Variable: at least one independent variable being manipulated by theresearcher.
    45. 45. Understanding the “evidence”
    46. 46. Levels of Evidence
    47. 47. Levels of Evidence
    48. 48. Levels of Evidence (pre 2010)• American Heart Association1. Positive randomized controlled trials.2. Neutral randomized controlled trials.3. Prospective, non-randomized controlled trials.4. Retrospective, non-randomized controlled trials5. Case series (no control group)6. Animal studies7. Extrapolations8. Rational conjecture (common sense)
    49. 49. Levels of Evidence• Used to be 7 (or 8  ) different ILCORlevels of Evidence (LOE).• In 2010 ILCOR reduced these to 5.• The AHA has broken these into threebroad categories• Level A – Highest standard of evidence.• Level B – Most common.• Level C – Anecdotal case reports,consensus opinions, retrospective studies,small studies, previous standard of carewithout evidence to contrary
    50. 50. KEY POINT:“ A recommendation with Level of Evidence B or C does not imply that therecommendation is weak.Many important clinical questions addressed in the guidelines do not lendthemselves to clinical trials. Even though randomized trials are notavailable, there may be a very clear clinical consensus that a particular testor therapy is useful or effective.”-2010 AHA ECC GuidelinesCirculation 2010;122;S657-S664
    51. 51. Classes of Recommendations• Most previous classes retained with better clarifications and descriptions.•“Class Indeterminate” recommendations, which were used in 2005, are notincluded in the 2010 AHA Guidelines for CPR and ECC. The elimination of theterm “Class Indeterminate” is consistent with the ACCF–AHA Classes ofRecommendation.•When the AHA writing groups felt that the evidence was insufficient to offer arecommendation either for or against the use of a drug or intervention, norecommendation was given.
    52. 52. Types of Studies: Randomized ControlledTrials• Randomized Controlled Trial (RCT): Gold Standard• A group of patients are randomized into an experimental group and a controlgroup. These groups are followed up for the variables/outcomes of interest.• RCTs most closely approximate the scientific method and are the most valid ofstudies.• A “double blind study” a type of RCT is one in which neither the patient northe physician knows whether the patient is receiving the treatment of interestor the control treatment.
    53. 53. Randomized Controlled Trial
    54. 54. Double Blind Study
    55. 55. Quasi-Experimental Studies• Quasi-experimental studies use intact groups of subjects rather thanassigning subjects to groups at random.
    56. 56. Quasi-Experimental Studies• Non-randomized controlled trial:• 1 group receives intervention• 1 group receives no-intervention (control)• Subjects assigned to groups by methods other than randomization.
    57. 57. Cohort Studies• A Cohort Study is a study in which patients who presently have acertain condition and/or receive a particular treatment are followedover time and compared with another group who are not affected bythe condition under investigation.
    58. 58. Cohort Study
    59. 59. Case-Control Studies• Case Control Studies: Case control studies are studies in whichpatients who already have a certain condition are compared withpeople who do not.
    60. 60. Case-Control Studies
    61. 61. Case Series/Report• A case series is a report on series of patients with an outcome ofinterest.• No control group is involved.•• “This one time, at band camp, I had a bunch of patients) with ABCcondition, we did XYZ treatment, and here is what happened as aresult. Aint it cool!”• A case report is a narrative report of a single interesting case.
    62. 62. Historical Studies• Historical studies are systematized searches for the facts and thenusing the information to describe, analyze, and interpret the past.
    63. 63. Systematic Reviews• A summary of the medical literature that uses explicit methods tosystematically search, critically appraise, and synthesize the worldliterature on a specific issue.
    64. 64. Meta-Analysis• A meta-analysis is a systematic review of multiple studies that havealready been done, rather than conducting a new study, to drawconclusions based on the whole of these studies…..
    65. 65. Meta-Analysis
    66. 66. Meta-Analysis• Meta-analysis of RCTs represents the highest level of scientificevidence.• Based on the theory that multiple RCT’s will show more truth than a singleRCT will….• Allows for more objective appraisal of the evidence.• Reduces the possibility of false negative or false positive results.
    67. 67. Meta-Analysis (Observational Studies)• Less valid than RCTs.• Still valid in that it gives better information of the population as awhole.• Most common means of studying EMS related interventions.• Many EMS interventions cannot be tested with an RCT as it might beunethical to withhold care from the control group.
    68. 68. Meta-Analysis (Observational Studies)• Conclusions:• 2 out of 3 trauma patients transported from the scene to a trauma centerhave minor injuries based on validated trauma scoring criteria.• 1 out of 4 patients transported are discharged from the emergencydepartment.
    69. 69. Animal Studies• Animal studies provide insight into biology, particularly into specificsystems.• For ethical reasons, some studies cannot be carried out on humans.But can be carried out on animals• Much resuscitation research conducted on pigs and dogs.• Much toxicology and neurological research conducted on mice.• Computer modeling are replacing many animal studies.
    70. 70. Expert Opinion• Expert opinions can take various forms:• Systematic reviews• Narrative reviews• Pure opinion pieces• Position Papers produced by organizations• Consensus papers• AMA• ACEP• NAEMTs
    71. 71. Evidence vs. Expert Opinion?• If CONSENSU Sis the basis for a guideline, how is this distinguishablefrom EVIDENCE-based guidelines?• What are the implications of having these guidelines LOOK equallyauthoritative when they make it to the street, when they ar ereallytwo different levels of evidence?
    72. 72. Rational Conjecture• Lowest level of scientific validity.• But, overall very important.• “You don’t have to run a Chi-Square test on common sense”
    73. 73. What is Psuedo Science?• Psuedo Science is weakly based conjecture often passed off as basedon science, often intentionally, with ulterior motives.• Herbal Supplements• “Tactical” medical products• Just make it black and wityh tons of Velcro and someone will buy it!• Targeted marketing• “Hero”/”Ricky Rescue” complex• It will often be supported with flashy presentations and plenty ofresearch, but when reviewed closely the research is conducted withbias and conflicts of interests, and the presentations are weaklyinterpreted extrapolations….
    74. 74. EBM: How does it fit together?• Rare to find a body of knowledge that “writes the guideline for you.”• Requires explicit cognitive steps that translate DIRECT evidence intoDIRECT guidelines through INFERENCES.• From “Bench Test” to “Bedside Test”• Example: Animal studies -> Human studies in limited settings -> Guideline appliedacross a broad population in dramatically different settings.• Inevitably requires judgment, extrapolation, experience, inference, andopinion
    75. 75. Summary• EMS must be driven by science.• Science is based upon quality research.• EMS providers of the future must be able to understand, and incertain cases, conduct valid research.
    76. 76. Summary• Evidence-Based Medicine:• EMS must start adhering to the tenets of evidence-based medicine.• Third-party payers will soon stop paying for care and procedures notsupported by science.• Litigation may follow if non-evidence-based practices continue.
    77. 77. Evidence-Based Medicine• Evidence-based medicine is not restricted to randomized controlledtrials and similar studies. It involves tracking down the best externalevidence with which to answer our clinical questions.
    78. 78. The End• Don’t be afraid of research. It canactually be fun!