Summer 2011
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A Perspective on Evidence-Based Medicine: Interview With William A. Miller
William A. Miller, PharmD, FCCP, FASHP
Professor of Clinical and Administrative Pharmacy
Division of Clinical and Administrative Pharmacy
University of Iowa College of Pharmacy
Iowa City, IA

Can you describe "Evidence-Based Medicine" in layman's terms?
I'm often asked about Evidence-Based Medicine (EBM). As I see it, in EBM a physician or other healthcare provider uses the best scientific evidence combined with his or her personal knowledge and expertise along with the patient's preferences concerning treatment decisions to make the best decision. For example, the personal preference of a patient might involve the cost of a drug treatment, if he or she cannot afford a more expensive treatment, even though evidence might suggest that a different drug would be a better choice. EBM is really the combination of using scientific evidence, the clinical expertise of the provider, and considering patient preferences. In recent years, we have moved from using EBM in making decisions about patients, but now about patient populations as well. For example, how do we treat patients with hypertension? How do we treat patients with asthma and other disease states? We can use EBM to determine what is best for the general treatment of a disease, and use that information along with clinical expertise and patient preferences to decide how organizations might best treat patients with certain conditions.

What is the opposite of evidence-based medicine? In other words, if EBM is new, what have physicians been doing until now?
I've been asked before whether EBM is really a new concept. I think it is a new term that has been applied to emphasize that medical decision-making by physicians, pharmacists and other care providers should be based on scientific evidence. It is my view that physicians, pharmacists and other providers have been using evidence to make decisions for a long time, even before the concept was popularized. The term EBM was really coined by some epidemiologists at McMaster University, who published it in 1991, and since then it has been popularized. Yet, if we go back, in the case of pharmacy, to the early 1960's and look at the establishment of drug information centers where physicians and other providers could ask drug information questions, and get answers to those questions that would be based on the medical literature. These centers were providing in essence evidence-based responses to drug information questions.

The value of what pharmacists do today as clinical pharmacists or clinical specialists is primarily in making evidence-based recommendations to physicians and other providers on how to use drugs to treat patients. Therefore, I think its not a totally new concept; it's a concept that has evolved and has stimulated organizations and individual practitioners to use more evidence in making medical decisions.

How and why is EBM better?
EBM is better because it is based upon the current evidence concerning what is best today to treat a patient. In contrast, most physicians, pharmacists and other providers have been relying primarily on the evidence or the knowledge they gained when they were trained and educated through their respective professional curriculum and post-graduate training. Therefore, what they use today in their practice is knowledge and clinical experience they gained by using a particular drug for the patients they have treated. It may not be as evidence-based today as it might have been 10 to 15 years ago, when they were training and learning how to use these drugs. I think the challenge is for physicians, pharmacists and other providers to constantly be looking at the latest evidence and use it in making medical decisions.

Why has EBM come about? What factors drove or are driving the development of EBM?
The early drug information centers were preparing reviews or doing monographs based on the literature to decide which drugs should be added to the hospital formulary. These early uses of evidence are examples of what we now call EBM.

Because the whole concept of using evidence has become more popular, we've seen HMOs, managed-care organizations and hospitals make decisions based upon evidence. One of the negative perceptions of EBM is equated with "cookbook" medicine, where there is no individual judgment made by providers and patient preferences are not taken into consideration. That was never the intent of the concept of EBM. Another common perception is that EBM focuses on using the cheapest or the less expensive drugs for treatment. Hence, some people believe formularies are primarily driven by economic and not clinical considerations.

The federal government has also been involved in promoting EBM, and created the Agency for Healthcare Research and Quality a few years ago. It supports EBM through research grants and publishes guidelines on how drugs or diseases should be managed.

I believe in the future, an increasing number of hospitals will utilize electronic medical records (EMR), which use evidence-based tools that are electronically transmitted during the time that physicians are prescribing to encourage them to use this information in decision making. These same tools will be used by pharmacists and nurses. Insurers and payers have also been a force in EBM, because they want to fund the least expensive drugs or the least expensive diagnostic techniques, based on evidence. If they can gather evidence that one drug is less expensive than and equally efficacious as another, they will only allow this drug to be used in their formulary.

Where does the evidence come from? Is there a particular body or organization that creates or verifies the it?
There is really no official organization that creates or verifies the evidence collected for EBM. The information comes from a variety of sources. We use the word "evidence" and it implies that all evidence is good evidence, but actually there's a ranking of what is considered the best evidence to support medical decision-making and what is considered the poorest evidence. What we would call the "gold standard" are randomized clinical trials and systematic reviews in which we review all of the trials, and we look across those trials to make decisions that are evidence-based. Next there are cohort studies and case reports and finally, there are panels of experts that offer their opinion on the best way to diagnose or treat a patient, based upon what they've read, their interpretation of the literature and their experiences. In summary, the best EBM occurs when the evidence comes from rigorous scientific research through randomized clinical controlled trials.

There are many sources for this information, including the Cochrane Collabora-tions, which was previously cited. They have published a collection of systematic reviews. You can also go online to various databases, the most popular of which is Medline. Or you also can search what's called M-Base on the Excerpta Medica site. You can search those databases and query to see if there are reviews that have been done on a particular topic, to answer a question for an individual patient situation or to assist in developing treatment guidelines for patient populations. Some professional organizations, such as the American College of Physicians, actually publish on-line analyses of topics that are germane to their physician group. You can find EBM anywhere in the literature. It's now much easier to find EBM sources because of the Internet and the explosion of information technology.

Is there an example of EBM that has proven to be beneficial?
The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (known as the JNC 7), is an example of an EBM guideline that has proven to be beneficial to physicians, pharmacists and other providers. This is a report that is periodically prepared by the National Heart, Lung and Blood Institute. The report examines what is the best evidence to support the prevention, evaluation and diagnosis and treatment of hypertension. It's probably one of the more highly read guidelines and it is used by P&T committees and individual pharmacists as a guide to the best therapy for patients with hypertension, either individually or as patient populations. But many other useful EBM guidelines are available for asthma, lipids, etc. When I say evidence-based, the example of the JNC 7 is what we call a synthesis technique, where you take all of the science and the literature and synthesize what is the best way to diagnose and treat hypertension. The JNC 7 also illustrates how the evidence keeps changing, hence, we now have the 7th version of these guidelines.

Is EBM simply a guideline with a fancy name? Why or why not? What's the difference between EBM and a guideline? How can EBM be incorporated into the clinical guideline development process?
Clinical guidelines today are one of the more common types of EBM tools that we have and I think some people have equated EBM solely with clinical guidelines for therapy or diagnosis. But in reality, clinical guidelines are just one type of EBM. Treatment algorithms and protocols are other examples. These tools are all designed to provide a generic way of managing a particular disease or condition. In reality, many of the questions that physicians and pharmacists have are very specific to a patient's condition and often they are not questions that can be answered by looking at guidelines, protocols or treatment algorithms. The only way these questions can be answered is to go to the literature and see if there are any current trials that may have answered a similar question regarding a specific patient or condition.

Will all physicians eventually practice EBM? What are some of the obstacles EBM faces?
I believe physicians, pharmacists and nurses always want to do what is best for their patients. They want to use the best evidence to make the best decision to help their patients get better. I don't think there is any question that physicians, pharmacists or nurses want to use EBM. Rather, it's all about the ease of access to information and the time constraints that they have in their practice. For pharmacists, with the advent of clinical pharmacists and clinical specialists, many of their jobs now focus on their role in providing drug information, and to do that they need to incorporate an evidence-based approach. The challenge to hospital pharmacy directors today is to create jobs that allow pharmacists the time and the resources, as well as the access to information so they can practice EBM or evidence-based pharmacotherapy.

How will EBM be evaluated? How will we know if it's working or if it is indeed better than an individual physician's opinion-based practice?
Research will answer the question as to whether or not EBM works. There have been large studies that have shown that using EBM approaches in making treatment decisions leads to reduced morbidity and mortality in patients. Therefore, we can conclude from some of those studies that EBM works. But it really depends upon what evidence you evaluate. For example, evidence using expert opinion may not be that accurate. What is best, in terms of outcomes, varies with one's perspective. Healthcare providers, like physicians, pharmacists and nurses, are looking for best outcomes from a clinical perspective. If we look at payors, they are concentrating on studies that indicate the most economically feasible alternative on how to treat a patient. If we look at the government, the current administration is beginning to promote the concept of prevention versus just treatment. But prevention is very expensive and we have confined or restrained resources. So these various approaches are driven by different perspectives on what is important in terms of outcomes.

In addition, patient satisfaction or quality-of-life studies analyze issues from the patient's perspective. For example, if a patient has cancer, comparing the quality of life on chemotherapy versus the surgical approach is a consideration.

Are there any pharmacy-specific or medication-specific EBM guidelines in place today?
Many of the professional organizations in pharmacy have for some time been publishing EBM reviews in their respective journals. For example, the American College of Clinical Pharmacy, through its journal, Pharmacotherapy, publishes EBM reviews of therapeutics, therapeutic classes or the use of drugs in particular disease conditions. One very good example of an EBM tool that is available within the hospital pharmacy is a book that ASHP publishes every year, titled Best Practices for Hospital and Health-System Pharmacy. It contains therapeutic guidelines that have been developed by groups within ASHP. The content of this book varies because some of the best practices are based on the opinions of thought leaders in pharmacy, and some of the evidence is based upon the review of clinical trials for the use of various drugs. One has to be careful in not taking every segment of the best practices book and concluding that it is scientifically sound, because the amount of science backing up each of these practices varies tremendously.

Will EBM be used only in the hospital or managed-care setting? Is it applicable to the community setting?
EBM practice is not driven by the environment. A significant factor for pharmacy is the job descriptions of the pharmacists. If we look today at hospitals, increasingly pharmacists are decentralized and function as clinical pharmacists or clinical pharmacy specialists. A major part of their role is to provide drug information to assist physicians in treatment planning and management. As a result, they are practicing EBM. In some hospitals today, they are not able to do that because of time constraints and their model for delivering pharmacy services. If we look at community pharmacies today, we find excellent examples of pharmacists practicing EBM. The numbers are much lower percentage-wise than what you would find in hospital pharmacy, but the examples are there and there are excellent practitioners in the community setting that are practicing EBM today. We expect to see a growth in EBM in the future in the community setting.

As I stated previously, many managed-care organizations use EBM as a tool to develop guidelines or control formularies that manage both clinical outcomes and cost. Almost all managed-care organizations are employing EBM in determining what they are going to fund and how they are going to manage patients.

What's in EBM for me as a patient? How will it benefit me?
From a patient perspective.patients want the best treatment for their condition or disease. They may not be able to articulate that this means they want the physician or pharmacist to use the best evidence to help decide how to treat or mange the condition, but that's really what they want. As a patient myself, I always want to go to someone that I am sure is using the best evidence to manage the disease or condition that I might have. I think patients will select the best experts to treat their condition or disease, because they want the best treatment. Patients are very concerned about the cost of medications; with the aging of our population, seniors are especially concerned about the costs of medication. They expect organizations to look at various medications to determine if one is more economical than another with similar outcomes. Today, most people accept that a generic drug is equivalent to the brand drug, because the FDA controls the manufacturing of these products to ensure that they are therapeutically equivalent. As a result, one can get a less expensive drug if one uses a generic. Managed-care organizations control access to drugs by requiring physicians to prescribe generics instead of brand names and by having patients pay a higher copayment to get a brand name drug.

Will EBM increase or decrease health care costs? How so?
EBM may actually both increase and decrease healthcare costs, depending on the findings from the EBM. For example, if research studies or randomized controlled trials prove that every adult who is 50 years or older should be placed on a lipid-lowering drug, because all people will eventually develop atherosclerosis, then putting everyone on lipid-lowering drugs is going to be an extremely expensive proposition and healthcare costs will go up. However, if placing patients on preventive drugs reduces the development of atherosclerosis, which in turn reduces the number of acute myocardial infarctions and other cardiovascular diseases, society might view the costs as warranted. Another example is the effort to stockpile smallpox vaccine and the projected stockpiling of bird flu vaccines. Why are we doing this? Because we know from studies that vaccines can prevent a huge number of deaths. Therefore, we are going to spend an enormous amount of money in a preventive manner, increasing healthcare costs.

On the other hand, we have a treatment guideline for hypertension that says the first line of treatment is the use of thiazide diuretics and ACE inhibitors, both of which are commonly available as generics and are very inexpensive. We compare the clinical outcomes of these drugs to more expensive medications, such as calcium channel blockers and new agents. In this case, we can use the less expensive products and still get comparable clinical outcomes while reducing the cost of healthcare.

Will EBM increase or decrease variability in medical or pharmacy practice? Is this good or bad?
In the future, EBM should lead to some decline in the variability of drugs that are used in the treatment of patients. I view this as a good outcome. One needs to keep in mind that the definition of EBM is to use not only the best science to decide how to manage patients, but also consider the clinical judgment of the physician or other provider and patient preferences. In many cases, there are no really excellent trials that will answer precisely the question you may have, which means there will always be some individualization in the way patients are treated and managed. I do believe that the ready access to EBM, the ready access to guidelines and the integration of EBM tools into EMR will lead to greater use of EBM, which will decrease the variability in how patients are managed. I would want to emphasize that this will probably lead to better patient outcomes.

Why is it important for P&T committee members to espouse EBM?
P&T committees need to be driven by the use of evidence in determing which medications are added to the formulary. Committee members review the evidence and use their clinical experience as part of the decision-making process. However, committees also need to consider what is best for a patient. For example, for many years, we believed it wasn't appropriate to have combination drugs on the formulary and we would have the patient take two drugs, even if it was the same time of day; this sometimes caused compliance problems for patients. Therefore, I think we have to look at patient issues as well. Will patients comply with the drug regimen? Can they afford the drugs?

Volume 20
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