Introduction to Evidence Based Medicine

Question 1

The father of westernized medicine

-Questioned the idea that gods caused illness and disease

Answer 1

Hippocrates

Question 2

A prominent example of how scientific findings are not always accepted

Answer 2

Pellegra

Question 3

In the early 1900’s Pellegra was contracted by over 100,000 Americans, mainly in the deep south. What are the symptoms?

Answer 3

The 4 D’s

1. ) Diarrhea
2. ) Dermatiti
3. ) Dimentia
4. ) Death

Question 4

Mostly seen in hospital for insane persons, orphanages, prisons, and very low income areas

-Attributed to a microbial infection

Answer 4

Pellegra

Question 5

Worked in the US department of hygiene and was the first to postulate that Pellegra was due to dietary deficiencies. But his results were not accepted

Answer 5

Dr. Joseph Goldberg

Question 6

In the 1920’s it was demonstrated that Pellegra was caused by

Answer 6

Niacin (Vitamin B3) Deficiency

Question 7

Demonstrated that stomach ulcers were caused by a bacterial infection from Heliobacter pylori in 1984. But their results were not accepted until 1997.

-Won nobel prize in 2005

Answer 7

Barry Warren and J. Robin Marshall

Question 8

What are five types of medical evidence?

Answer 8

1. ) Diagnostic Studies
2. ) Prognostic Studies
3. ) Treatment Studies
4. ) Prevention Studies
5. ) Etiology Studies

Question 9

Ask, “how sure can I be that a patient has a diagnosis?”

Answer 9

Diagnostic Studies

Question 10

Ask “What should this patient expect following this surgery, this exposure, this diagnosis?”

Answer 10

Prognostic Studies

Question 11

Asks “What are the causes or risk factors for the condition?”

Answer 11

Etiology Studies

Question 12

When an old treatment is tested, and the results find that the treatment makes the patient no better, or no worse

Answer 12

Reversal

Question 13

When a new treatment is tested and the treatment is found to be beneficial

Answer 13

Replacement

Question 14

The conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients

Answer 14

Evidence Based Medicine (EBM)

Question 15

Who originated evidence based medicine?

-designed the first randomized control trial (RCT)

Answer 15

Sir Bradford Hill

Question 16

According to Archie Cochrane (1971) an intervention is only “effective” if it has been demonstrated, preferably by a RTC to

Answer 16

Do more good than harm

Question 17

Anything that has an “effect” can also have

Answer 17

Side effects and risks

Question 18

Out of 100 children with strep throat,

Answer 18

86 correctly detected w/ the rapid tes

-14 will be missed

Question 19

Out of 100 children with non-strep sore throat

Answer 19

95 will be correctly classified w/ the rapid test

-5 will be misdiagnosed

Question 20

What are the five A’s that evidence-based medicine includes to access the medical literature and determine its relevance to the patient?

Answer 20

Ask, Acquire, Appraise, Apply, Assess

Question 21

“POEMS” are patient oriented outcomes that matter. They encompass the 5 D’s, which are?

Answer 21

Death, Disease, Discomfort, Disability, Dissatisfaction

Question 22

Addresses areas of uncertainty and change in medical practice

Answer 22

Evidence-based medicine

Question 23

All the people in a defined setting or with certain defined characteristics that the researcher is interested in

Answer 23

Population

Question 24

The subjects from the population who are studied

Answer 24

Samples

Question 25

The goal of clinical research is to generalize the results to the rest of the

Answer 25

Population of interest

Question 26

The confidence with which the results can be accurately generalized to the population

Answer 26

External validity

Question 27

A representative sample looks like the

Answer 27

Population

Question 28

Are non-representative samples that decrease external validity

Answer 28

Biased Samples

Question 29

To get a more representative sample, we want

Answer 29

Larger sample sizes

Question 30

Identify who will be in the study

Answer 30

Inclusion criteria

Question 31

Makes the sampling more manageable, controls variability (improving internal validity), and limits generalizability (external validity)

Answer 31

Inclusion and Exclusion criteria

Question 32

When each member of the population has an equal chance to be included in the research

Answer 32

Probability sampling

Question 33

The most common form of probability sampling

Answer 33

Simple random sampling

Question 34

To ensure that critical variables are represented in the sample, subjects are stratified by traits and then randomly sampled

Answer 34

Stratified random sampling

Question 35

A type of random sampling done when subjects are ordered. -For example, the 3rd person from each letter of the alphabet can be chosen

Answer 35

Systematic sampling

Question 36

Systematic sampling can incorporate stratification if there is a

Answer 36

Meaningful order

Question 37

Non-probability sampling methods do not involve random selection. Three examples are

Answer 37

Purposive sampling, convenience sampling, and quota sampling

Question 38

Hand-picking patients

Answer 38

Purposive sampling

Question 39

People are chosen based on availability of volunteering

Answer 39

Convenience sampling

Question 40

Convenience sampling with specific quotas included. This is like stratified sampling

Answer 40

Quota sampling

Question 41

Factors or attributes in a research study that can have different values (ex: occupation, height, BMI, etc)

Answer 41

Variables

Question 42

Variables that can be manipulated by the researcher

Answer 42

Independent variables

Question 43

Measured outcomes. These may be "primary endpoints" or "secondary endpoints" in a study, aka: response variables or outcome variables

Answer 43

Dependent variables

Question 44

In a study that seeks to determine if a drug works to relieve pain, what is the 1. ) Independent variable? 2. ) Dependent variable?

Answer 44

1. ) Drug: Drug has 2 levels, drug and no drug | 2. ) Pain reliefe

Question 45

Other variables in the study that may affect the relationship between the independent and the dependent variables

Answer 45

Extraneous variables

Question 46

If researchers wanted to examine whether relaxation therapy was better than drug therapy for reducing the number of tension headaches in medical students, what would be some extraneous factors to control or account for?

Answer 46

Diet, other medications, severity of headaches

Question 47

A process at any stage of interference tending to produce results that depart from the true values

Answer 47

Bias

Question 48

Occurs when comparisons are made between non-equivalent groups

Answer 48

Selection Bias

Question 49

When extraneous factors, selection bias, or measurement bias occur, a study is -A fatal flaw in research

Answer 49

Confounded

Question 50

Occurs when the methods of measurement are dissimilar among groups of patients

Answer 50

Measurement bias

Question 51

Occurs when two factors are associated (travel together) and the effect of one is confused with or distorted by the effect of the other

Answer 51

Confounding

Question 52

The variation in the measurements that occurs for any reason -expressed as spread in the data

Answer 52

Random Error (Chance error)

Question 53

How can we limit the random error?

Answer 53

Limit the population, improve the measurements, and control the testing environment

Question 54

The internal health of the study, i.e. how free it is from bias and chance

Answer 54

Internal validity

Question 55

The degree to which you can generalize the results of the study back to the population of interest

Answer 55

External validity

Question 56

If you wanted to study grade school kids, and you wanted to be absolutely sure you got a representative sample from each grade level, you would use

Answer 56

Stratified sampling (i.e. take a SRS from 1st grade, then 2nd grade, then 3rd, and so on)

Question 57

Used less in clinical studies, but more in epidemiology studies

Answer 57

Probability sampling

Question 58

Seen often in a qualitative study

Answer 58

Purposive sampling

Question 59

If two groups you are studying have different diets or different types of headaches, or differ in any way, this is an example of

Answer 59

Selection bias

Question 60

If extraneous variable are not controlled,they result in

Answer 60

Confounding