The term evidence-based medicine may be new to most people. However, the idea it represents has been around for ages. Health care professionals have made decisions for their patients’ care based on scientific evidence for centuries. Today, the emphasis on incorporating scientific evidence into the practices of various clinicians is even greater.
Evidence-based medicine is a way to apply the best available scientific evidence to make clinical decisions. It helps clinicians decide what information to believe and what is useful. This process typically involves the following steps:
For instance, we would use the steps to decide whether a new drug that claims to cure a disease can actually do so. Evidence (studies) relating to this new drug would be collected. Then the evidence gathered would be evaluated based on the quality of the study or trial.
Different types of scientific studies exist, and they must be judged differently. Pharmaceutical (medication) trials are a type of study often talked about in the media. Generally, these provide the strongest level of evidence. Observational studies and case studies are examples of other types of scientific studies. The evidence from these is not as strong.
Pharmaceutical trials are judged on aspects like:
Done properly, pharmaceutical trials are the gold standard because they always use at least two groups of participants. One group takes the drug in question, while the other does not. Other aspects of the trial are kept the same for all participants. This ensures that the results of the trial are due to the treatment, not from other factors that might interfere. Finally, any conclusions found about the new drug are assessed for value and use in real life.
As you can see, health care professionals consider many factors when evaluating drug claims. However, most people who hear about a new drug or new side effect cannot go into this much detail. And so the last two questions of the process are the most important. Ask yourself if what you are hearing can be trusted. If so, does it apply to your situation? Consider these questions the next time you see or hear something about a drug or treatment.
When you hear new drug claims, you often do not immediately know who supplied the information. Looking at that source can often tell you how reliable the information is. Essentially, there are two sources for much of the drug information — the one that you hear it from, and the source that actually generated the information. The source that you hear it from (a friend, magazine, article, the news) can give you an idea of whether the information is trustworthy. However, you must look at the original source of the information to know how reliable it really is.
If the information is from the news, check where it is coming from – which scientific study, journal, or institution. If you hear something from a friend, ask where they heard it from and have a look yourself. Magazines and articles should, and often do, have sources for their information. If you cannot find a source, that should be a warning sign. When you do find the source, ask yourself if it seems reliable. Is the institution where the study was done well known? Is the scientific journal that published the study credible? Is information on how the pharmaceutical trial was done easily available?
Statistics can be a powerful tool in both a positive and negative way. Used correctly, they give a fuller understanding of the information being presented. However, statistics can also be misleading. Those who publish studies sometimes try to phrase statistics in ways that make results sound more significant than they may be.
For instance, consider the following claim: drug A has been shown to reduce the risk of developing disease B by 50 per cent. On the surface, drug A sounds like a miracle drug, and maybe it is. However, ask yourself a few questions. In this example, the claim refers to reducing risk of disease B, but what is the normal risk of getting disease B? If two people out of a thousand are normally at risk, and drug A decreases that risk to one out of a thousand, is this significant? The risk is technically decreased by 50 per cent, but as you can see, it was never a very high risk.
This is just one example of how statistics can be misleading. When considering statistics, ask yourself what the numbers actually mean. And of course, the old saying often applies – if it sounds too good to be true, it probably is.
To truly assess something new about a drug, the information must be put into context. Most of the drug claims you hear about already have existing data. In the case of a new drug for a particular disease, certain facts are known about the disease. Specifically, we know what has been used to treat that disease until now, and how effective that treatment has been. If effective drugs are already available, then the question to ask is what would be the real benefit of this new drug.
In the case of an existing drug with a newly discovered side effect, there would be information about the drug to date. Here, we can look at an overall body of information about the drug, its effectiveness, and other side effects and risks. It is important to understand this new side effect in the context of the drug as a whole. Then, the question is whether and how this will change the way people use this drug.
Even if the answers to the previous questions mean the information is accurate and trustworthy, the conclusions may not apply to everyone. Evidence-based medicine standardizes making decisions, which sometimes means we lose sight of the individual. Ask yourself if the information you find is useful to your situation. Each person is unique. Just because a treatment helps participants of a study does not mean it will help a particular individual. Likewise, a treatment that did not work for participants in a study may still benefit a certain person. If the claim being made is based on a study or trial, ask whether it had participants similar to you. Participants are often selected based on age, other medical conditions, medications used, and sometimes even gender and ethnicity. Look too at whether the drug being used would be appropriate for you given your own medical history.
When considering any treatment, you must weigh the benefits versus the risks. A health care professional can help you decide, based on your unique situation.