JAMES O. PAGE

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JAMES O. PAGE

• No ones death comes to pass without making some
  impression, and those close to the deceased
  inherit part of the liberated soul, and thus
  become richer in their humaneness.

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An Introduction to EMS Research

• Bryan Bledsoe, DO, FACEP
• Midlothian, Texas

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Definitions

• Research careful, systematic, patient study and
  investigation in some field of knowledge,
  undertaken to discover or establish facts or
  principles.

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Definitions

• Science
• The state or fact of knowing knowledge.
• Systematized knowledge derived from observation,
  study, and experimentation carried on in order to
  determine the nature or principles of what is
  being studied.

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Is EMS Art or Science?

• The knowledge of EMS is science.
• The way it is applied is art.
• Excellent EMTs know the science of EMS and use
  the art of EMS to apply the science.

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Art or Science?

• Some health practices are more about art than
  science.
• Chiropractic, for example, has little science and
  a lot of art.

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Art or Science?

• Neurology today has a great deal of science and
  little art.

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Art or Science?

• When you have a life threatening illness or
  injury, would you seek out a health care provider
  whose practice was more art or more science?

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Art or Science?

• EMS is the safety net of society.
• We are often the first to provide care to the
  injured and the infirm.
• Our practices must be based on science.

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But we must apply them with art!
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Research

• Most medical research is based on the application
  of the scientific method.

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The Scientific Method

• The scientific method is the process by which
  scientists, collectively and over time, endeavor
  to construct an accurate (that is, reliable,
  consistent and non-arbitrary) representation of
  the world.

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The Scientific Method

• Steps
• Observe some aspect of the universe
• Invent a tentative description, called a
  hypothesis, that is consistent with what you
  observed.
• Use the hypothesis to make predictions.
• Test those predictions by experiments or further
  observation and modify the hypothesis in the
  light of your results.
• Repeat steps 3 and 4 until there are no
  discrepancies between theory and experiment
  and/or observation.

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The Scientific Method

• Hypothesis groundwork, foundation supposition
  an unproven theory.

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The Scientific Method
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The Scientific Method

• The great advantage of the scientific method is
  that it is unprejudiced.
• 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.
• Faith, defined as a belief that is not based on
  logical proof or material evidence, does not
  determine whether a scientific theory is adopted
  or discarded.

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The Scientific Method

• A theory is accepted not based on the prestige or
  convincing powers of the proponent, but on the
  results obtained through observations and/or
  experiments which anyone can reproduce.
• The results obtained using the scientific method
  are repeatable.

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The Scientific Method

• There are many types of pseudoscientific
  theories which seem based on a mantle of apparent
  experimental evidence but that, when examined
  closely, are nothing but statements of faith.

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The Scientific Method

• Faith is believing what you know aint so.
• Mark Twain, 1894
• Following the Equator

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Science versus Pseudoscience

• How to tell the difference.
• Anecdotes do not make a science.
• Scientific language does not make a science.
• Bold statements do not make claims true.
• Heresy does not equal correctness.
• Reversal of the burden of proof.
• Rumors do not equal reality.

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Science versus Pseudoscience

• How to tell the difference.
• Failures are rationalized.
• Use of emotive words and false analogies.
• Ad ignorantiam reasoning (if you cant disprove a
  claim, it must be true).
• Ad hominem or tu quoque statements.
• Overreliance on authorities.
• Circular reasoning.
• Reductio ad absurdum reasoning.

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The Scientific Method

• Pseudoscience is still a major part of our
  culture. Many practitioners resort to
  pseudoscience and other anecdotal practices.

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The Scientific Method

• Typically uses terms and images to appear
  scientific.

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The Scientific Method

• Reliance on names and anecdotes.
• Dr. Greg Cynaumon?
• Physician?
• Psychologist?
• Nutritionist?
• Chiropractor?
• Masters and Doctorate in psychology from Sierra
  University (known diploma mill).

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The Scientific Method

• No clinical evidence CortiSlim works.
• No information about contents (natural or
  herbal).
• Dr. Talcott fringe nutritionist with loose
  affiliations with University of Utah.
• One of the largest scams in recent history.

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Observation During a discussion you and your
  coworkers bring up the idea that there are more
  psychiatric emergencies when the moon is full.
• Hypothesis Psychiatric emergencies are more
  common when the lunar cycle is in the full moon
  phase.

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Prediction You predict that there will be more
  EMS calls for psychiatric emergencies when the
  moon is full as compared to other times of the
  month.

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Testing You set up an experimental protocol to
  test your hypothesis.
• For this you
• Determine you will conduct the study for a year.
• Determine when a full moon is scheduled to
  appear.
• Determine that you will declare two days before
  and two days after the full moon a five-day full
  moon period.

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• For this you
• Define what a psychiatric emergency will be.
• 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?

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Use of the Scientific Method in EMS

• For this you
• Analyze the data based on the number of
  emergencies that arose during full moon periods
  and compare to the number of emergencies during
  the other periods.
• Perform any statistical tests necessary to
  understand the data.

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Use of the Scientific Method in EMS

• Results

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Results Your study finds
• During full moon period 0.5 of patients were ?
  patients.
• During other period 0.8 of patients were ?
  patients.
• During the entire study period 0.7 of patients
  were ? patients.

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Results Your study finds
• The incidence of ? patients during the full moon
  period was 0.15 patients per day.
• The incidence of ? patients during the other
  moon phases was 0.25 patients per day.
• The incidence of ? patients overall was 0.23
  patients per day.

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Psych patients are less common during the full
  moon.
• HYPOTHESIS DISSPROVED!

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Use of the Scientific Method in EMS

• Use of the scientific method in EMS.
• Revise hypothesis
• New hypothesis Psychiatric emergencies are no
  more frequent during full moon lunar phases than
  during other lunar phases.
• HYPOTHESIS ACCURATE.
• Report findings. Paper should be detailed enough
  that anybody can follow it and repeat your
  experiment.
• Repeat study to determine whether findings can be
  repeated.

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EMS Research

• The more valid a study, the closer it is to the
  truth!

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EMS Research

• Bias
• A mental leaning or inclination partiality
  prejudice bent.
• The more a study design adheres to the scientific
  method, the less chance for bias to affect the
  outcomes.

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EMS Research

• Bias (sometimes flat deception) has been a common
  practice in medicine and EMS.
• Quackery and bias still permeates many aspects of
  modern healthcare.

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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.
• 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.

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EMS Research

• 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 the independent
  variable.
• Independent Variables the variables that affects
  (or is assumed to affect) the dependent variable
  under study.
• Experimental Variable at least one independent
  variable being manipulated by the researcher.

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Levels of Evidence
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Levels of Evidence

• Center for Evidence-Based Medicine (Oxford)
• Ia. Meta-analysis of RCTs
• Ib. One RCT.
• IIa. Controlled trial without randomisation.
• IIb. One other type of quasi-experimental study.
• III. Descriptive studies, such as comparative
  studies, correlation studies, and case-control
  studies.
• IV. Expert committee reports or opinions, or
  clinical experience of respected authorities or
  both.

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Levels of Evidence

• American Heart Association
• 1. Positive randomized controlled trials.
• 2. Neutral randomized controlled trials.
• 3. Prospective, non-randomized controlled
  trials.
• 4. Retrospective, non-randomized controlled
  trials
• 5. Case series (no control group)
• 6. Animal studies
• 7. Extrapolations
• 8. Rational conjecture (common sense)

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Study Designs

• Randomized Controlled Trial (RCT)
• A group of patients are randomized into an
  experimental group and a control group. These
  groups are followed up for the variables/outcomes
  of interest.
• RCTs most closely approximate the scientific
  method and are the most valid of studies.

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Randomized Controlled Trial
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EMS Research

• Houston MAST Study
• Constant All patients with abdominal trauma with
  hypotension transported by the HFD to Ben Taub
  Hospital.
• Dependent Variable survival from trauma.
• Independent Variables age, sex, location of
  injury, transport time, etc.
• Experimental Variable Application or
  non-application of the MAST.

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Example

• Mattox KL, Bickell B, Pepe PE, Burch J, Feliciano
  D. Prospective MAST study in 911 patients. J.
  Trauma. 1989291104-12
• 911 trauma patients gt 15 years of age with
  systolic BP lt 90 mmHg were randomized by
  alternate day assignment. All transported by HFD
  to Ben Taub hospital trauma center.
• Experimental variable MAST or no-MAST
• Dependent variable survival from trauma

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Example

• Independent variables etiology, age, race, sex,
  location of injury, trauma scores, injury
  severity scores. Scores revealed the two groups
  to be statistically identically matched.
• Findings Mortality rate 31 in the MAST group
  and 25 in the non-MAST group.
• Difference statistically significant.

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Double Blind Study

• A double blind study is one in which neither the
  patient nor the physician knows whether the
  patient is receiving the treatment of interest or
  the control treatment.
• It is a type of RCT.

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Double Blind Study
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Double Blind Study

• Bracken MB, Shephard MJ, Collins WF, et al. A
  randomized, controlled trial of
  methylprednisolone or naloxone in the treatment
  of acute spinal-cord injury. NEJM
  1990322(20)1405-11
• Patients with spinal cord injury randomized by
  computer to receive methyprednisolone, naloxone,
  or placebo.
• Researchers and patients did not know which drug
  was which (prepared in pharmacy)

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Quasi-Experimental Studies

• Quasi-experimental studies use intact groups of
  subjects rather than assigning subjects to groups
  at random.

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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.

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Cohort Studies

• A Cohort Study is a study in which patients who
  presently have a certain condition and/or receive
  a particular treatment are followed over time and
  compared with another group who are not affected
  by the condition under investigation.

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Cohort Study
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Cohort Studies

• Framingham Heart Study
• People in Framingham, MA have been followed for
  over 50 years.
• Conducted by National Heart, Lung, and Blood
  Institute (NHLBI) and Boston University.
• 5,209 residents between 30 and 60 years of age
  initially enrolled.
• In 1971, 5,124 children (and their spouses) of
  the original cohort added.
• 500 minority members have been added.

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Cohort Studies

• Framingham Heart Study
• Every two to four years, study participants are
  given extensive medical examinations including a
  medical history, blood tests and other
  sophisticated tests such as bone scans, eye exams
  and echocardiograms assessing multiple aspects of
  their current health status.

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Cohort Studies

• Framingham Heart Study (results)
• Risk factors for heart disease identified.
• Better understanding of the effects of lifestyle.
• More than 1,000 papers published significantly
  adding to the knowledge base of heart disease.
• Study continues.

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Case-Control Studies

• Case Control Studies Case control studies are
  studies in which patients who already have a
  certain condition are compared with people who do
  not.

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Case-Control Studies
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Case Series

• A case series is a report on a series of patients
  with an outcome of interest. No control group is
  involved.

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Case Report

• A case report is a narrative report of an
  interesting case.

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Historical Studies

• Historical studies are systematized searches for
  the facts and then using the information to
  describe, analyze, and interpret the past.

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Historical Studies

• Bledsoe BE, Smith MG. Medical Helicopter
  Accidents in the United States A 10-Year Review.
  J Trauma. 2004561325-1329

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Historical Studies

• Methods Review of all air medical helicopter
  accidents in the US from 1997-2002 from the NTSB
  database.

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Systematic Reviews

• A summary of the medical literature that uses
  explicit methods to systematically search,
  critically appraise, and synthesize the world
  literature on a specific issue.

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Systematic Reviews

• Bledsoe BE. Critical Incident Stress Management
  (CISM) Benefit or Risk for Emergency Services?
  Prehosp Emerg Care. 20037272-279

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Meta-Analysis

• A meta-analysis is a systematic review that uses
  quantitative methods to summarize the results.

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Meta-Analysis
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Meta-Analysis

• Meta-analysis of RCTs represents the highest
  level of scientific evidence.
• Allows for more objective appraisal of the
  evidence.
• Reduces the possibility of false negative
  results.

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Meta-Analysis

• van Emmerik AAP, Kamphuis JH, Hulsbosch AM,
  Emmelkamp PMG. Single-session debriefing after
  psychological trauma a meta-analysis. Lancet.
  2002360766-771

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Meta-Analysis
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Meta-Analysis (Observational Studies)

• Less valid than RCTs.
• Still valid in that it gives better information
  of the population as a whole.
• Many EMS interventions cannot be tested with an
  RCT as it might be unethical to withhold care
  from the control group.

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Meta-Analysis (Observational Studies)

• Bledsoe BE, Wesley AK, Eckstein M, Dunn TM,
  OKeefe MF. Helicopter transport of trauma
  patients a meta-analysis (in press).
• Observational meta-analysis examining validated
  trauma scoring systems in trauma patients
  transported from the scene to a trauma center.

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Meta-Analysis (Observational Studies)

• Conclusions
• 2 out of 3 trauma patients transported from the
  scene to a trauma center have minor injuries
  based on validated trauma scoring criteria.
• 1 out of 4 patients transported are discharged
  from the emergency department.

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Animal Studies

• Animal studies provide insight into biology.
• For ethical reasons, some studies cannot be
  carried out on humans.
• Computer modeling are replacing many animal
  studies.

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Expert Opinion

• Expert opinions can take various forms
• Systematic reviews
• Narrative reviews
• Pure opinion pieces

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Rational Conjecture

• Lowest level of scientific validity.
• But, overall very important.
• You dont have to run a Chi-Square test on
  common sense

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Summary

• EMS must be driven by science.
• Science is based upon quality research.
• EMS providers of the future must be able to
  understand, and in certain cases, conduct valid
  research.

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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 not supported by science.
• Litigation may follow if non-evidence-based
  practices continue.

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Evidence-Based Medicine

• Evidence-Based Medicine is
• The conscientious, explicit and judicious use of
  the current best evidence in making decisions
  about the care of individual patients.
• Evidence-Based Medicine is not
• Cook-book medicine
• Cost-cutting medicine
• Old-hat nor impossible to practice

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Evidence-Based Medicine

• Evidence-based medicine is not restricted to
  randomized controlled trials and similar studies.
  It involves tracking down the best external
  evidence with which to answer our clinical
  questions.

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The End

• Dont be afraid of research. It can actually be
  fun!

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