Evidence - Based Medicine Flashcards
*A _________, biomedical perspective
What is Evidenced-Based Medicine?
FITB (fill in the blank) Positivistic
______ - ______ approach to the practice of medicine
What is Evidenced-Based Medicine?
Problem-oriented
Seeks to improve patient care by considering the quality of clinical evidence.
What is Evidenced-Based Medicine?
Founded upon an ideal that decisions about the care of individual patients should involve the “conscientious, explicit and judicious use of current best evidence.”
What is Evidenced-Based Medicine?
What is Evidenced-Based Medicine?
Clinical Judgement
Relevant Scientific Evidence
Patients’ Values and Preferances
EBM Hierarchy - Primary Studies
Randomized Control Trial
Cohort Studies
Case Control Studies
EBM Hierarchy - Primary Studies which of the 2 of the three are Observational Studies?
Cohort Studies
Case Control Studies
EBM Hierarchy - Secondary, Pre-appraised, or filtered Studies
Clinical Practice Guidelines
Meta-Analysis
EBM Hierarchy - No Design
Case Report or Case Studies
EBM Hierarchy - Not involved w/ Humans
Animal and Lab Studies
EBM uses “_______ -standards”
gold
T/F A Randomized Control Trial (RCT) is a research study “gold standard”
True
T/F An RCT is the most accepted scientific method of determining the (ideally) unbiased evaluations of the benefit of a drug or a therapeutic procedure.
True
T/F EBM is considered to represent the “best” evidence available, which ideally should be integrated with clinical judgement and patient values into the final decision about the management of a condition by healthcare practitioners.
True
The Randomized Controlled Trial is a study design that _______ assigns participants into an experimental group or a control group.
randomly
As the study is conducted, the only expected difference between the control and experimental groups is the ______ or ______ variable being studied.
intervention or outcome
RCT Otherwise known as:
_______ AND ______
CAUSE AND EFFECT
Any tendency that limits impartial consideration of a question or issue.
Bias
In academic research, bias refers to a type of ______ ______ that can distort measurements and/or affect investigations and their results.
systematic error
Confounder Bias
Selection bias
Performance bias
Detection bias
Attrition bias
Reporting bias
Other biases
Types of bias in Research
Distorts the treatment effect due to a variable ______ ______ ______ ______ that causes an imbalance between treatment groups.
Confounder Bias
associated with the outcome
Differences between baseline characteristics of the groups that are compared.
Selection bias
Differences between groups in the care that is provided, or in exposure to factors other than the interventions of interest.
Performance bias
Differences between groups in how outcomes are determined.
Detection bias
- Differences between groups in withdrawals from a study that leads to incomplete outcome data
- Exclusion * Attrition
Attrition bias
- Differences between reported and unreported findings. * Focus on the positive reports, omit the negative.
Other biases
Reporting bias
- Trial design and appropriate statistical analysis.
Other biases
The most effective way to prevent confounding in a RCT?
Randomization of the Groups
Randomization ______ result in the balanced distribution of all potential confounders (known or unknown) across all treatment groups at baseline
should
T/F Essentially Randomization of the Groups, thus creating a level playing field in order to compare apples to apples or same to same
True
T/F Well-designed and executed RCT’s allow one to ______ causation rather than correlation
Infer
to derive as a conclusion from facts
or premises - we see smoke and infer fire— L. A.White— compare IMPLY
Infer
GUESS, SURMISE - your letter … allows me
to infer that you are as well as ever— O. W. Holmes †1935
Infer
The _______ is a schematic created to help us understand how to weigh different levels of evidence in order to make health-related decisions.
It provides perspective for the results of each study design, based on the relative strengths and weaknesses of each design.
Pyramid
Information and expert opinion
Background information
Can be influenced by beliefs, opinions, or even politics.
This level might also include anecdote.
This level is where questions are Asked NOT Answered.
Level 1: Foundation
Case control studies or case series reports
Early stages of research. Studies help identify variables that might predict
a condition, or treatment response.
Case Studies look at individuals who have a unique presentation and provide detail on the history, intervention and outcome. Detailed and descriptive.
Case Series reports usually include only a few participants who are given a similar intervention and follow-up. Detailed and descriptive.
Case Control Studies look retrospectively at individuals and compare with a similar group who did not have the intervention.
Small numbers of participants, frequently not randomized and confounding variables not controlled.
Level 2: Stage 1 Testing
Cohort studies - Also called longitudinal or epidemiological
Follow a large group of people over an extended period to see how their exposures affect
their outcomes.
Normally used to look at the effect of suspected risk factors that cannot be controlled experimentally – for example, the effect of smoking on lung cancer.
Frequently used to determine long term effects of a lifestyle, diet, or other interventions. May include a second group that did not engage in the same intervention as a control
comparison.
Can be generalized to a larger population, but can be difficult to blind, can’t control for outside variables, and are usually not randomized.
Level 3: Effect
The Randomized Control Trial
Level 4: RCT
TRUE experimental design =
Randomized
T/F A large Double Blinded Randomized Control Trial is the most reliable “test”
TRUE
Y/F study design and depending on the question, provides the strongest support of a cause and effect relationship.
TRUE
Critically Appraised Topics
Not actually a study design
They are short summaries of the best available evidence
Considered a secondary source
An abbreviated systematic review created to
answer a specific question
Level 5/6: Pre-Systematic Review
Systematic Reviews
Almost the pinnacle of the Evidence-Based Medicine Pyramid
Panoramic view of all of the evidence about an intervention, considered the strongest and highest quality of evidence
Comparison of the results of studies side by side. Considered a secondary source.
Level 7: Systematic Review
_______ ________ guidelines are recommendations for clinicians about the care of patients with specific conditions. They should be based upon the best available research evidence and practice experience.
Level 8 (not shown): Clinical Practice Guidelines
The foundation is a systematic review of the research evidence bearing on a clinical question, focused on the strength of the evidence on which clinical decision-making for that condition is based.
Clinical Practice Guidelines
. A set of recommendations, involving both the evidence and value judgments regarding benefits and harms of alternative care options, addressing how patients with that condition should be managed, everything else being equal.
Clinical Practice Guidelines
A collection of beliefs or practices mistakenly
regarded as being based on scientific method
Pseudo = Fake:
“A new phenomenon in clinical trials has arisen over the past 20 years. Complementary and alternative medicine (CAM) or integrative medicine (IM) modalities based on principles that bespeak infinitesimally low prior probability of success or that even violate_____________________________________ are being tested in randomized clinical trials (RCTs).”
well-established laws of physics and chemistry
the major assumption underlying EBM is that by the time an investigational treatment is ready for RCTs it has passed all preclinical tests and has thus demonstrated ________ plausibility.”
biological
“In RCTs testing modalities with low pre-test probability (i.e., low plausibility), confounding effects are vastly________, easily producing false-positives.”
magnified
- Accumulated body of scientific knowledge describing the basic principles of nature.
- Physics, Chemistry and Biology
- Facts, laws and theories established through proper scientific methodology that form a basic understanding of how the world works.
- It would take extraordinary evidence to overturn them.
Basic Sciences
- Real-world applications of the facts, laws and theories from the basic sciences.
- Uses the principle of reductionism
- Applied science observations can be explained via basic science fundamentals.
Applied Sciences
Applied Sciences uses the principle of__________
reductionism
In RCTs testing modalities with low pre-test probability (i.e., low _______ ), confounding effects are vastly magnified, easily producing false-positives.”
What is Low Plausibility?
(fitb) plausibility
randomized experiments oversimplify causation
Objections to RCTs summarized
cannot be carried out in complex institutional and other settings or to test complex ________
Objections to RCTs summarized
interventions
ignore the role of theory in understanding intervention effectiveness
Objections to RCTs summarized
perfectly good alternatives to RCTs that pose none of these problems exist and should therefore be used instead.
Objections to RCTs summarized
Medical decision-making draws upon a broad spectrum of knowledge including basic science, scientific evidence, individual scientific medical education, personal experience, personal biases and values, ______ ______ , economic and political considerations, and philosophical and social principles.
patient values
T/F Theory choices are never determined exclusively by the _________
TRUE
Evidence
Theory choices are never determined exclusively by the evidence.
A body of evidence may support many different or even contradicting theories.
* The ‘most_________ adequate’ theory must be chosen
Choice is subject to preference, bias, the social, political, or research agenda at play
empirically
T/F Non cis het men have been underrepresented as subjects in clinical trials.
TRUE
The disease, not the patient dictates the direction of the study, but the results are applied to the patient.
EBM is disease oriented
