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.”
An Introduction to EMS Research Bryan Bledsoe, DO, FACEP Midlothian, Texas
Definitions • Research: careful, systematic, patient study and investigation in some field of knowledge, undertaken to discover or establish facts or principles.
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.
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.
Art or Science? • Some health practices are more about art than science. • Chiropractic, for example, has little science and a lot of art.
Art or Science? • Neurology today has a great deal of science and little art.
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?
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.
Research • Most medical research is based on the application of the scientific method.
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.
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.
The Scientific Method • Hypothesis: groundwork, foundation supposition; an unproven theory.
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.
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.
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.
The Scientific Method • “Faith is believing what you know ain’t so.” • Mark Twain, 1894 “Following the Equator”
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.
Science versus Pseudoscience • How to tell the difference. • Failures are rationalized. • Use of emotive words and false analogies. • Ad ignorantiam reasoning (if you can’t disprove a claim, it must be true). • Ad hominem or tu quoque statements. • Overreliance on authorities. • Circular reasoning. • Reductio ad absurdum reasoning.
The Scientific Method • Pseudoscience is still a major part of our culture. Many practitioners resort to pseudoscience and other anecdotal practices.
The Scientific Method • Typically uses terms and images to appear “scientific”.
The Scientific Method • Reliance on “names” and anecdotes. • Dr. Greg Cynaumon? • Physician? • Psychologist? • Nutritionist? • Chiropractor? • Master’s and Doctorate in psychology from Sierra University (known diploma mill).
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.
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.
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.
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.”
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?
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.
Use of the Scientific Method in EMS • Results:
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 Ψ patients. • During other period 0.8% of patients were Ψ patients. • During the entire study period 0.7% of patients were Ψ patients.
Use of the Scientific Method in EMS • 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 per day. • The incidence of Ψ patients overall was 0.23 patients per day.
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!
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.
EMS Research • The more valid a study, the closer it is to the truth!
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.
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.
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.
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.
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.
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)
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.
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.
Example • Mattox KL, Bickell B, Pepe PE, Burch J, Feliciano D. Prospective MAST study in 911 patients. J. Trauma. 1989;29:1104-12 • 911 trauma patients > 15 years of age with systolic BP < 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
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.
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.