ebm part 1

Evidence-Based Medicine:

What it is and why you

need it Clista Clanton,

MSLS, AHIP

Topics Covered What is EBM? EBM milestones Why is EBM important? Complimentary/Alternative medicine Practice guidelines

What is EBM?

“the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.”1

1. Sackett DL, et al. Evidence-Based Medicine: What it is and what it isn’t. BMJ 1996; 312:71-2.

The integration of individual clinical expertise with the best available external clinical evidence from systematic research.

In simpler words… A question is asked…Can grape seed oil help

prevent and treat Alzheimer’s? ALL evidence is sought and examined

systematically. A quality criteria is set, and low quality evidence

is discarded. Wherever possible, the evidence is quantified.

What EBM is not Something physicians have been doing for

ages. “Cookbook” medicine. A tool for administrators and insurers. Restricted to randomized trials and

systematic reviews. Opposed to patient centered medicine.

EBM Milestones

Pierre Charles Alexander Louis (1787-1872) Founder of the "numerical

method" (medical statistics) in medicine and the champion of exact observation and conservative deduction in medical studies

First modern clinicianPhysician letting blood from a patient. British Library, London. From "Den medeltida kokboken", the Swedish translation of The

Medieval Cookbook

EBM Milestones

Ernest Amory Codman (1869-1940) End Result Idea:”The common

sense notion that every hospital should follow every patient it treats, long enough to determine whether or not the treatment has been successful, and then to inquire ‘if not, why not?’ with a view of preventing similar failures in the future.”2

2. Codman EA. The Shoulder: Rupture of the Supraspinatus Tendon and Other Lesions in or About the Subacromial Bursa. Boston: Thomas Todd Co., 1934:V-XL.

EBM Milestones 1948 – new method of conducting clinical

trials first reported

3. Doll R. Controlled trials: the 1948 watershed. BMJ 1998;317:1217-1220.

Randomly allocating individuals after entry into the trial eliminates bias and provides a proper estimate of random error.

First modern randomized trial, "Streptomycin Treatment of Pulmonary Tuberculosis."

EBM Milestones

Archie Cochrane Effectiveness and Efficiency: Random

Reflections on Health Services (1972).

because resources would always be limited, they should be used to provide equitably those forms of health care which had been shown in properly designed evaluations to be effective.

stressed the importance of using evidence from randomized controlled trials (RCT’s) because these were likely to provide much more reliable information than other sources of evidence.

Paradigm Shift in Medicine

Foundations of the paradigm shift lie in developments in clinical research over the last 30 years.

4. Centre for Health Evidence. Evidence-based medicine: A new approach to teaching the practice of medicine. Available at http://www.cche.net/usersguides/ebm.asp#7.

In 1960, RCT’s were rare. Now, virtually no drug can enter clinical practice without a demonstration of its efficacy in clinical trials

Meta-analysis is gaining increasing acceptance as a method of summarizing the results of a number of randomized trials, and ultimately may have as profound an effect on setting treatment policy as have randomized trials themselves.

Methodological advances have been made in other areas, such as the assessment of diagnostic tests and prognosis.4

Old Paradigm Unsystematic observations from clinical experience are a valid way of

building and maintaining one's knowledge about patient prognosis, the value of diagnostic tests, and the efficacy of treatment.

4. Centre for Health Evidence. Evidence-based medicine: A new approach to teaching the practice of medicine. Available at http://www.cche.net/usersguides/ebm.asp#7

The "Introduction" and "Discussion" sections of a paper could be considered an appropriate way of gaining the relevant information from a current journal.

A combination of thorough traditional medical training and common sense is sufficient to evaluate new tests and treatment.

Content expertise and clinical experience are a sufficient base from which to generate valid guidelines for clinical practice.

To sort out clinical problems, physicians can reflect on their own clinical experience, reflect on the underlying biology, go to a textbook, or ask a local expert.

The study and understanding of basic mechanisms of disease and pathophysiologic principles is a sufficient guide for clinical practice.

New Paradigm

Clinical experience, and the development of clinical instincts are crucial and necessary parts of becoming a competent physician. At the same time, systematic attempts to record observations in a reproducible and unbiased fashion markedly increase the confidence one can have in knowledge about patient prognosis, the value of diagnostic tests, and the efficacy of treatment. In the absence of systematic observation one must be cautious in the interpretation of information derived from clinical experience and intuition, for it may at times be misleading.


New Paradigm The study and understanding of basic mechanisms of disease are

necessary but insufficient guides for clinical practice. The rationales for diagnosis and treatment which follow from basic pathophysiologic principles may in fact be incorrect, leading to inaccurate predictions about the performance of diagnostic tests and the efficacy of treatments.


Clinicians should be able to critically appraise the "Methods" and "Results" sections of journal articles.

Understanding certain rules of evidence is necessary to correctly interpret literature on causation, prognosis, diagnostic tests, and treatment strategy.

Clinicians should regularly consult the original literature in solving clinical problems and providing optimal patient care.

What is EBM?

“Evidenced-based medicine is the concept of formalizing the scientific approach to the practice of medicine for identification of “evidence” to support our clinical decisions. It requires an understanding of critical appraisal and the basic epidemiologic principles of study design, point estimates, relative risk, odds ratios, confidence intervals, bias, and confounding. By using this information, clinicians can categorize evidence, assess causality, and make evidence-based recommendations. Evidence-based medicine allows analysis of complicated material so that we can make the best possible clinical decisions for the populations we serve.”5

5. Williams JK. Understanding evidence-based medicine: a primer. Am J Obstet Gynecol 2001:185-275-278.

Why is EBM Important?

New types of evidence are being generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis, usually physicians don’t get it.

6. Covell DG, Uman GC, Manning PR: Information needs in office practice: Are they being met? Ann Intern Med 1985;103:596-9.

How much is actually being applied to patient care?

1. lack of time

2. out-of-date textbooks, and

3. the disorganization of the up-to-date journals6

Why is EBM Important? Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physician’s knowledge of up to date care and the years that have elapsed since graduation from medical school.7

7. Ramsey PG, Carline JD, Inui TS et al: Changes over time in the knowledge base of practicing internists. JAMA 1991;266:1103-7.8. Davis DA, Thompson MA, Oxman AD, Haynes RB: Changing physician performance. A systematic review of the effect of continuing medical education strategies. JAMA 1995;274:700-5.

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional, instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients.8

Why is EBM important? Knowledge translation

– increasing the uptake of the best available evidence into practice – has always been a challenge Scurvy: use of citrus

was proven to prevent and cure scurvy in 1754, but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir t.d.s No change

Seawater No change

Garlic, mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1. Lind’s study on scurvy:17479

9. The James Lind Library. Available from http://www.jameslindlibrary.org/. Accessed 26 June 2008.

Why is EBM important? Chloride of lime: In 1846 Ignatz Semmelweis attributed puerperal fever to an

infection carried by obstetricians. Despite reducing maternal mortality from 18 to 1.2% by hand-washing in chloride of lime, his findings were rejected by the medical society of Vienna. It would take until the 1890’s before it was accepted that microorganisms can cause disease.

Period

Characteristics of period No. deliveries

No. maternal deaths

Maternal deaths/1000 deliveries

1784-1822

No routine post-mortems 71,395 897 12.5

1823-1838

Routine post-mortems 65,035 3,745 57.6

1839-1847

Clinic arrangements changedFirst clinic: doctors and studentsSecond clinic: midwives

20,20417,791

1,989 691

90.233.8

1848-1859

Hand-washing introducedFirst clinicSecond clinic

47,93840,770

1,7121,248

35.730.6

Table 2. Mortality rates and characteristic of obstetrics clinics in Vienna 1784-185910

EBM processes can help with dissemination and adoption

Role of Literature Searching

Can improve the treatment of medical inpatients, even those already receiving evidence-based treatment.

Random sample of 146 inpatients cared for by 33 internal medicine attending physicians.

After physicians committed to a specific diagnosis and treatment plan, investigators performed standardized literature searches and provided the search results to the attending physicians.

Attending physicians changed treatment for 23 (18%) of the 130 eligible patients as a result of the literature searches.8

11. Lucas BP, Evans AT, et al. The impact of evidence on physician’s inpatient treatment decisions. J Gen Intern Med 2004;19:402-409.

Complimentary/Alternative Medicine

Complementary and alternative medicine is a group of diverse medical and health care systems, practices, and products that are not presently considered to be part of conventional medicine.

12. National Center for Complementary and Alternative Medicine. Understanding complementary and alternative medicine. Available at:http://nccam.nih.gov/health/.

While some scientific evidence exists regarding some CAM therapies, for most there are key questions that are yet to be answered through well-designed scientific studies--such as: Are these therapies safe?

Do these therapies work for the diseases or medical conditions for which they are used?

Are Complimentary and Alternative Medicine Interchangeable Terms?

Complementary medicine is used together with conventional medicine. Example: Using aromatherapy to help lessen a patient's discomfort following surgery.

12. National Center for Complementary and Alternative Medicine. Understanding complementary and alternative medicine. Available at: http://nccam.nih.gov/health/.

Alternative medicine is used in place of conventional medicine. Example: When Suzanne Somers rejected chemotherapy in favor of a drug called Iscador (uses extracts of Mistletoe) to treat her breast cancer.

Major Types of Complementary and Alternative Medicine

Alternative medicine systems: Built upon complete systems of theory and practice. Examples: homeopathic medicine, naturopathic medicine, traditional Chinese medicine, Ayurveda.


Mind-body interventions: Uses a variety of techniques designed to enhance the mind's capacity to affect bodily function and symptoms. Some techniques that were considered CAM in the past have become mainstream (patient support groups and cognitive-behavioral therapy). Other mind-body techniques are still considered CAM, including meditation, prayer, mental healing, and therapies that use creative outlets such as art, music, or dance.

Major Types of Complementary and Alternative Medicine cont. Biologically Based Therapies: Use

substances found in nature (herbs, foods, and vitamins). Example: shark cartilage to treat cancer.


Examples of dietary supplements that have been incorporated into mainstream medicine:

Folic acid to prevent birth defects

Regimen of vitamins and zinc to slow the progression age-related macular degeneration (AMD).

Major Types of Complementary and Alternative Medicine cont.

Manipulative or Body-Based Methods: Based on manipulation and/or movement of one or more parts of the body. Examples: chiropractic or osteopathic manipulation, massage.


Energy Therapies: Involve the use of energy fields. Biofield therapies: intended to affect energy fields that

purportedly surround and penetrate the human body (the existence of such fields has not yet been scientifically proven). Examples: qi gong, Reiki, Therapeutic Touch.

Bioelectromagnetic-based therapies: unconventional use of electromagnetic fields, such as pulsed fields, magnetic fields, or alternating-current or direct-current fields.

NCCAM

National Center for Complementary and Alternative Medicine Part of NIH, established in 1998 Dedicated to exploring complementary and alternative healing

practices in the context of rigorous science, training complementary and alternative medicine (CAM) researchers, and disseminating authoritative information to the public and professionals.

NCCAM Web site (nccam.nih.gov): publications, information for researchers, frequently asked questions, and links to other CAM-related resources.

NCCAM Clinical Trials

Use of Alternative/Complementary Medicine in the U.S.

36% of U.S. adults aged 18 years and over use some form of complementary and alternative medicine.

CAM use was greater among women; people with higher education; those who had been hospitalized within the past year; and former smokers, compared to current smokers or those who had never smoked.

13. Barnes P, Powell-Griner E, McFann K, Nahin R. CDC Advance Data Report #343. Complementary and Alternative Medicine Use Among Adults: United States, 2002. May 27, 2004.

Practice Guidelines “an amalgam of clinical experience, expert opinion,

and research evidence.”9

14. Cook DJ, et al. The relation between systematic reviews and practice guidelines. Ann Intern Med. 1997;127:210-216.

Evidence-based guidelines will have: Rigorous review methods

Synthesis of higher quality primary research

Practice guideline development can vary in quality and methods

Stakeholders involved

Degree of reliance on formal literature reviews

Degree to which expert opinion prevails

How ultimate recommendations are expressed

Where to Find Guidelines

National Guideline Clearinghousehttp://www.guideline.gov

Index databases such as Medline http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=usalibhttp://southmed.usouthal.edu/library/ovid.htm(Use MeSH heading “Practice Guideline”)

References1. Sackett DL, et al. Evidence-Based Medicine: What it is and what it isn’t. BMJ 1996; 312:71-2.2. Codman EA. The Shoulder: Rupture of the Supraspinatus Tendon and Other Lesions in or About the

Subacromial Bursa. Boston: Thomas Todd Co., 1934:V-XL.3. Doll R. Controlled trials: the 1948 watershed. BMJ 1998;317:1217-1220.4. Centre for Health Evidence. Evidence-based medicine: A new approach to teaching the practice of

medicine. Available at http://www.cche.net/usersguides/ebm.asp#7.5. Williams JK. Understanding evidence-based medicine: a primer. Am J Obstet Gynecol 2001:185-275-278.6. Covell DG, Uman GC, Manning PR: Information needs in office practice: Are they being met? Ann Intern Med

1985;103:596-9.7. Ramsey PG, Carline JD, Inui TS et al: Changes over time in the knowledge base of practicing internists. JAMA

1991;266:1103-7.8. Davis DA, Thompson MA, Oxman AD, Haynes RB: Changing physician performance. A systematic review of

the effect of continuing medical education strategies. JAMA 1995;274:700-5.9. The James Lind Library. Available from http://www.jameslindlibrary.org/. Accessed 26 June 2008.10. The James Lind Library. Available from http://www.jameslindlibrary.org/. Accessed 26 June 2008.11. Lucas BP, Evans AT, et al. The impact of evidence on physician’s inpatient treatment decisions. J Gen

Intern Med 2004;19:402-409.12. National Center for Complementary and Alternative Medicine. Understanding complementary and

alternative medicine. Available at: http://nccam.nih.gov/health/.13. Barnes P, Powell-Griner E, McFann K, Nahin R. CDC Advance Data Report #343. Complementary and

Alternative Medicine Use Among Adults: United States, 2002. May 27, 2004.14. Cook DJ, et al. The relation between systematic reviews and practice guidelines. Ann Intern Med.

1997;127:210-216.

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