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EMS RESEARCH atic reviews guide our most important decisions, but more commonly, a combination of research studies and research methods guides the decisions that are made. Consider the following types of medical research: SYSTEMATIC REVIEW In a systematic review, a series of studies pertaining to a single question is evaluated. Their results are reviewed, summarized and used to draw evidence-based conclusions. It is important to remember that a systematic review is made up of not one, but many different research experiments. RANDOMIZED CONTROLLED TRIALS (RCTs) In an RCT, researchers randomly assign eligible subjects into groups to receive or not receive the intervention being tested. A control group is used to compare the tested theory against a known outcome. In 2000, for example, Marianne Gausche-Hill and her colleagues looked at pediatric intubation in Los Angeles County, CA. In their study, children needing airway management were randomized, based on the day of the week, to either an intubation group or a bag-valve-mask (BVM) group. Outcomes of these patients were studied. Objectivity was improved because subjects were randomized and the results were more meaningful, as they could compare outcomes of the intubation group against the control BVM group. In medicine, drugs are frequently tested in randomized studies using a placebo.To measure the outcome of a drug, patients are frequently randomized to receive either the real drug or a placebo, or "sugar pill," which has no effect. Frequently these studies use a double-blinding process so that even the providers carrying out the study, as well as the patients, do not know which path they are taking. In this type of study, the results of the new medication can be compared against the placebo control group to accurately assess the effect of the therapy. COHORT/CONCURRENT CONTROL/ CASE-CONTROL STUDIES In these types of studies, two groups or therapies or patients are compared, Questions to Ask Regardless of the type of study you are reading, you should always review research in a way that helps you identify bias or flaws in the methodology. There is certainly a great deal more to learn about the evaluation of medical research, but there are some important questions to consider when reading a study. Consider the following questions: 1. Was the study randomized, and was the randomization blinded? 2. If more than one group was reviewed, were the groups similar at the start of the trial? 3. Were all eligible patients analyzed, and if they were excluded, why were they excluded? Bias often occurs by removing data that leads in a diferent direction from your hypothesis. Often, the removal of patients from a study can identify potential problems. 4. Were the outcomes really the result of the therapy? Consider the previously discussed example of the new airway device being used in only sicker patients. Occasionally, outcomes can be measured that would have happened randomly. For example, a company could invent a new device that, it claims, would make the sun rise tomorrow at 6 a.m. Although the company could certainly produce a study that demonstrates the desired outcome, that outcome would have occurred whether the device was used or not. A powerful study is one that can be reproduced with the same results in relatively diferent circumstances. 5. Is the outcome truly relevant? Many studies show diferences among treatment but no real relevance. For example, a study might show that a new medication increases the return of spontaneous circulation in sudden cardiac arrest compared with a placebo control group. Getting a pulse back in more patients is important, but that result is not really relevant if exactly the same number of patients die at the conclusion of care as compared with the control group. but subjects are not necessarily randomized. For example, you might compare the outcomes of one service that uses continuous positive airway pressure (CPAP) against the outcomes of another service that does not. A cohort study might follow patients who have a specific disease and compare them with a group of patients that does not have the disease. In both studies, you are comparing two groups and have a control group, but the results are not truly randomized. Frequently, case-control studies are retrospective in nature, looking at two groups of events or outcomes that occurred in the past. All these studies can be valid and yield important information, but they also can be prone to bias in that it is difficult to control all aspects of similarity and methods among the different groups. CASE SERIES/CASE REPORTS Case studies and case reports review the treatment of a single patient or a series of patients. Frequently they report on unusual circumstances or outcomes. There is no control group and these reports are always retrospective.They are certainly not as valid as randomized studies, but they often help us formulate larger questions to be investigated. META-ANALYSIS A meta-analysis is not truly a study itself, but a compilation of different studies looking at a single topic. A meta-analysis will summarize the work of others and frequently will comment on outcomes. In many cases, these are similar to a systematic review, but frequently are of a much smaller scale. Conclusion Learning more about this topic as a provider will help you to understand the decisions and discussions that are ongoing both in EMS and in healthcare in general. Classes, textbooks and many other tutorials can improve your capability to read and evaluate research. However, there is no better way to learn about research than to become involved in a research study. Daniel Batsie, EMT-P, is the EMS program coordinator at Eastern Maine Community College in Bangor, ME, and clinical and education coordinator for Atlantic Partners Regional EMS. Joseph J. Mistovich, MEd, NREMT-P, is chair of the Department of Health Professions and a professor at Youngstown State University in Youngstown, OH. He has more than 25 years of experience as an educator in emergency medical services. He is an author or coauthor of numerous EMS books and journal articles and is a frequent presenter at national and state EMS conferences. Daniel Limmer, AS, EMT-P, has been involved in EMS for 31 years. He is active as a paramedic with Kennebunk Fire-Rescue in Kennebunk, ME. A passionate educator, Dan teaches basic, advanced and continuing education EMS courses throughout Maine. EMSWORLD.com | MARCH 2013 61