Ebp Test 2

Front 1

what are the three basic categories of clinical decisions?

Back 1

1. abdication
2. induction
3. deduction

Front 2

what is abdication?

Back 2

clinical decision based primarily on the advice of an expert

Front 3

what are sources of abdication?

what is the do all sources of abdication have in common?

Back 3

sources:
1. teachers, colleagues, instructors
2. sales reps (you should use this cool wound care thing)
3. textbooks (written by "experts")
4. continuing education seminars (taught by "experts")

All sources of abdication lack clinical evidence, which is bad

Front 4

what is induction?

Back 4

clinical decision based on UNCONTROLLED clinical experience or the extension of basic science to the clinical arena

"i've seen it work thousands of times, so it should work."

"Anatomically it makes sense, so it should work"

Front 5

what are 4 common examples of induction?

why is induction not that good?

Back 5

1. comparing new to old techniques
2. before and after studies
3. animal studies
4. healthy control studies

not that good because:
1. Designs do not LIMIT error or bias
2. tend to focus on SURROGATE ENDPOINTS.

Front 6

what kind of endpoints does Induction focus on?

Back 6

surrogate endpoints

Front 7

what is a primary endpoint?

what are 3 examples?

Back 7

it is an endpoint that is of interest to the patient or society. an endpoint that matters to the patient or society

1. mortality
2. stroke
3. pain

Front 8

what is a surrogate endpoint?

3 examples?

Back 8

an endpoint that is of interest to the professional

1. strength
2. ROM
3. Girth

Front 9

What is this an example of?

Study of antiarrhythmic drugs (encainide)

Patients with ventricular tachycardia

after 6 months - the drug eliminated the rhythm in 54% of the patients

after 18-30 months - the drugs eliminated the rhythm in 29% of patients

The conclusion you would get is "encainide is a safe, well-tolerated antiarrhythmic agent"

Back 9

Induction

Front 10

what is the fatal flaw in induction?

Back 10

it is not capable of exposing bad conclusions about efficacy, even when the observations upon which it operates are totally accurate

Front 11

what is deduction?

Back 11

clinical decisions based on PROSPECTIVE studies designed to answer specific clinical questions or TEST specific clinical research hypothesis

Front 12

deduction
4 cool things about it

Back 12

1. there is a SPECIFIC clinical question or hypothesis you are trying to answer
2. it involves a clinical population
3. it has rigorous and appropriate design
4. Deduction addresses a primary endpoint.

recall that a primary endpoint is something that matters to the patient or society
1. mortality
2. stroke
3. pain

Front 13

RCT are used in what strategy of making a clinical decision?

Back 13

deduction

Front 14

Deduction time

RCT of antiarrhythmic drugs
Patients w/ ventricular tachycardia

the OUTCOME studied was cardiac death (1. what kind of endpoint is this)

2. what was the result of this study? what does this tell us about how good induction is?

Back 14

1. primary outcome (it matters to the paitient, mortality)

2. 2.64 times more likely to die in the drug group vs. placebo. this tells us that induction isn't that good b/c it didn't have a comparison.

Front 15

definition of deduction

Back 15

the best information on whether a given treatment or test does more good than harm to patients w/ a given disorder... and then followed for clinically relevant outcomes of their disease

Take home message is to use research evidence based on deduction as much as possible

Front 16

clinical decision should be made by considering these three factors:

Back 16

1. research evidence - good research on diagnosis, prognosis, and interventions

2. clinical expertise - able to identify what is wrong w/patient and to weigh different types of treatment

3. patient characteristics - preferences, concerns, expecations, this also has to be included in the clinical decision

Front 17

definition of research evidence

Back 17

clinically relevant (important, applicable) research into diagnostic tests, prognostics tests, interventions.

Front 18

definition of clinical expertise

Back 18

the ability to use skills and past experience to rapidly identify each patient's unique health state and weigh potential interventions

Front 19

definition of patient characteristics

Back 19

unique preferences, concerns and expectations of each patient which must be integrated into decision making

Front 20

definition of evidence

Back 20

data collected from clinical research studies performed on patients

Front 21

definition of theory

tell me an example of a theory that has to do w/ ultra sound

Back 21

data from basic science research or observation

basic science shows us that ultrasound will increase blood flow. This information from basic science has lead to the theory that ultrasound will facilitate the healing process and speed the healing of musculoskeletal conditions b/c of the increased blood flow caused by ultrasound.

this is not evidence. its is a conclusion drawn from basic science research, aka a theory

theoretically, ultrasound should work (but it doesn't)

Front 22

tell me an example of evidence involving ultrasound

Back 22

a RCT study, wow!

26 subjects w/ heel pain
Randomized to two groups
group 1 - true ultrasound for a specific amount of time
group 2 - "sham" or fake worthless ultrasound for the same amount as group 1

Guess what happened?

There is no difference in reduction of pain after 4 weeks! No difference, Fail to reject null hypothesis, p> 0.05

Front 23

definition of null hypothesis

Back 23

there is no difference between treatment A and treatment B

Front 24

definition of alternate hypothesis

Back 24

there is a difference between treatment A and treatment B

Front 25

definition of p-value

for example, p = .4

Back 25

the chance that the null hypothesis is true

if p = .4, that means there is a 40% chance that the null hypothesis is true, meaning there is a 40% chance there is no difference btwn treatment A and treatment B. p>0.05, therefore we fail to reject the null hypothesis, meaning there is no difference btwn the two treatments

Front 26

"ultrasound SHOULD improve blood supply and speed healing" is an example of a _____

Back 26

theory

Front 27

"studies on patients w/ various musculoskeletal conditions have NOT found ultrasound to be better than sham ultrasound or other comparison treatments." this is an example of _________

Back 27

evidence baby!

Front 28

not all evidence is a strong as others.

tell me three examples of evidence, shitty or not

Back 28

1. inductive studies
2. case studies
3. deductive studies (RCT)

all these are forms of evidence

Front 29

What are the rankings from best to worst forms of evidence
1.
2.
3.
4.
5.
6.

Back 29

1. Systematic review of RCT (of course RCT are the best, systematic reviews are even better)
2. a single RCT (a single RCT is better than a whole bunch of observational studies put together)
3. Systematic review of observational studies w/ patient-important outcomes
4. single observational studies w/ patient important outcoms
5. physiologic studies
6. unsystematic clinical observations (just looking at what you see at the clinic)

Front 30

what are advantages to systematic reviews?

Back 30

1. it combines data from different individual studies
2. gives us a consensus, and agreement = gives us an idea of the consistency of results, more precise

Front 31

what is the disadvantage to systematic reviews?

Back 31

you need to have HIGH QUALITY individual studies

Front 32

what are advantages of RCTs?

Back 32

1. provides definitive results
2. reduces bias (known and unknown bias) by making the groups the same w/ randomization

Front 33

what are the disadvantages of RCTs?

Back 33

you have to make an inference from a group of patients (the sample in the study) to the patient standing in front of you = you must decide if its applicable

Front 34

what are advantages of observational studies?

Back 34

1. Cheap!
2. can detect low rate occurences (like certain cancers are really rare, and you can't give someone cancer, so if there's a few people w/ rare cancer you can observe them)

Front 35

what are disadvantages of observational studies?

Back 35

1. the treatment effect is often inflated
2. BIAS IS INEVITABLE - no control man! who knows what other stuff contributed to the outcome

Front 36

what are advantages of physiologic studies?

Back 36

1. It tells us about the underlying mechanism

ultrasound increases blood flow

Front 37

what are disadvantages of physiologic studies?

Back 37

it focuses on SURROGATE endpoints (ROM, strength, girth, outcomes that are important to the clinician)

since physiologic studies focus on surrogate endpoints, they lack clinical meaning, and good results (ultrasound increasing blood flow) does not always lead to meaningful changes in primary endpoint (mortality, pain, stroke)

Front 38

advantages of unsystematic clinical observations

Back 38

1. its a good starting point

2. it helps you generate hypotheses or theories

say you see something in the clinic that worked for a certain person, like that young girl that was forced into extension by her mom. it worked for that patient, so it can lead you to for hypotheses and starting point for other studies.

Front 39

disadvantages of unsystematic clincial observations

Back 39

limited scope
can't consider:
1. natural history (getting better on their own)
2. placebo effects (get better b/c they believe that seeing a PT will make them better)
3. patient/health care worker expectations,
4. patients desire to please (patient will want to make clinician happy, so will try to make themself better somehow.)

Front 40

what are components of an evidence based approach

Back 40

research evidence

clinical expertise

patient characteristics.

Front 41

what are the 5 steps in evidence based practice?

Back 41

1. patient creates the need for information
2. the "information need" is converted into a question that can be answered
3. the evidence is consulted(you look up articles)
4. the evidence is appraised (you decide if the article is any good)
5. clinical performance is evaluated

Front 42

definition of background questions

Back 42

questions about general knowledge regarding the medical aspect instead of a specific PT component

what is the target disorder?
who usually gets this target disorder?
what may have led to the target disorder?

Front 43

definition of foreground questions

Back 43

questions about specific knowledge regarding PT managment (how do i fix it?)

they are questions about
1. diagnosis - tests, compare to gold standard
2. prognosis - factors predicting outcomes
3. interventions - benefits, risks, cost, time
4. outcomes - self-report measures, disability, quality of life

Front 44

What clinical tests can confirm the diagnosis of spinal instability in patients w/ lbp?

what are the most effective exercises to improve function and decrease pain in patients w/ spinal instability.

These two are examples of ________ questions.

Back 44

foreground

Front 45

foreground questions do what?

Back 45

help the clinician in answering questions about specific PT management of a problem.

Front 46

novice (noobs) tend to ask what type of questions?

Back 46

background questions

Front 47

expert clinicians tend to ask what type of questions?

Back 47

foreground questions

Front 48

what is a primary source?

Back 48

the ORIGINAL research.

includes opinion WITH DATA

example is a research paper

VERY IMPORTANT - systematic reviews and Meta-analysis does not qualify as a primary source!!!!

Front 49

what is a systematic review and meta-analysis?

Back 49

several good quality studies combined into one large study

Front 50

are systematic reviews and meta-analysis considered a primary source?

Back 50

NO. systematic reviews and meta-analysis are SECONDARY SOURCES(a combination of other works)

a primary sources is the original research. it is ONE study.

Front 51

what is a secondary source?

Back 51

a COMBINATION of other works.

it DOES NOT INCLUDE DATA (except for systematic reviews. systematic reviews show data, but they are still considered SECONDARY SOURCES)

Front 52

do secondary sources include data?

Back 52

no.

except for systematic reviews, which show data. still considered a secondary source.

Front 53

what are some examples of secondary sources?

Back 53

1. review articles (systematic reviews)
2. textbooks (often outdated)
3. reference manuals

Front 54

what kind of questions are textbooks may be useful for?

Back 54

background questions.

Front 55

what kind of questions are textbooks usually not useful for?

Back 55

foreground questions

Front 56

in a secondary source, would a methods and results section be included?

Back 56

no

Front 57

review status

tell me about peer-reviewed papers

Back 57

1. subjected to peer-review process
2. listed in PubMed
3. scholarly articles

Front 58

review status

tell me about non-peer-reviewed papers

Back 58

1. newspapers
2. popular magazines
3. professional magazines

Front 59

should you use a peer-reviewed, primary source?

Back 59

yes

Front 60

would you use a non-peer-reviewed, secondary source?

Back 60

no

Front 61

peer-reviewed, secondary source

Back 61

acceptable (a systematic review)

Front 62

Should you use?

non-peer reviewed, primary sources

Back 62

depends. you decide the quality of the study

Front 63

what is a filtered data base

Back 63

people choose what studies to put in a data base.

Front 64

what is an unfiltered data base?

Back 64

all studies are put in a data base

Front 65

what are advantages of filtered databases?

Back 65

1. each article is reviewed
2. strong studies are usually selected (but not always)

Front 66

what are disadvantages of filtered database?

Back 66

2. you have to rely on other people to assess the quality of the article, when ideally you should judge the quality yourself.

2. accessibility may be an issue

Front 67

so if a database has specific criteria of what studies to include (archive), then what kind of database is it?

Back 67

filtered datbase

Front 68

what are advantages of unfiltered databases?

Back 68

1. comprehensive - it has all the studies
2. accessible

Front 69

what are disadvantages of unfiltered databases?

Back 69

1. time consuming - there's so many studies to sift through
2. often requires specific searches to access disired information

example is PubMed

Front 70

sickness is a combination of these three things:

Back 70

1. target disorder
2. Illness
3. Predicament

Sickness = target disorder + illness + predicament

sickness is the sum of target disorder, illness, and predicament

Front 71

what is the definition of target disorder

Back 71

the thing that is wrong w/ you. the disease.

Front 72

what is the definition of illness?

what is its 2 components?

Back 72

the RESULTS of having the target disorder

1. Symptoms
2. Signs

Illness = signs + symptoms

Illness is the sum of signs and symptoms

Front 73

what is the definition of symptoms?

Back 73

what the patient percieves

"my knee hurts when i run"

"i have pain in my knee when i squat"

symptoms (what the patient complains about) tend to guide what signs the clinician is going to look for.

a patient complains about knee pain, so the clinician looks at the knee

Front 74

what is the definition of signs?

(signs vs. symptoms)

Back 74

what the clinician percieves

ex:
how much ROM the patient has

Front 75

definition of predicament

Back 75

the social, psychological, and economic fashion in which the patient is situated in the environment.

how the target disorder and sickness is affecting the patient's environment, every day life

Ex: insurance coverage, work-related injury, cultural issues, anxiety and health-care workers

Front 76

sickness is the complete picture

1. meniscal pain
2. "i have knee pain"
3. swelling
4. can't make it to bball practice

Back 76

1. target disorder
2. symptom (patient complaint)
3. sign (what the clinician sees)
4. Predicament - how the target disorder and illness affects the patient's social/daily life

remember that symptoms and signs together make up Illness

Front 77

definition of diagnosis

Back 77

the process of finding out what is wrong w/ the patient, and it leads us to how we can help them

Front 78

explain the evidence based approach to diagnosis

Back 78

knowing how to select and interpret diagnostic tests in order to rule in or rule out a target disorder.

Front 79

medical diagnosis is traditionally the role of the _______

and it is geared toward the ______ of pathology

Back 79

physician

identification

done with:
1. imaging studies
2. blood work
3. tissue culture

Front 80

definition of examination

it has 3 components, which is discussed in a separate slide

Back 80

its is comprehensive screening and testing

it is the identification of impairments, functional limitations, and disabilities

Front 81

what are the 3 components of examination?

Back 81

1. History - gather current info, get history that is related to why the patient is seeking PT
2. Systems review - anatomical and physiological status
3. tests and measures - gathering data

Front 82

definition of Evaluation

Back 82

evaluation is what you do w/ the info you gathered during the examination.

evaluation is the clinical judgement from the data gathered

evaluation is the putting together of history, systems review, and tests and measures

evaluation leads to an action

Front 83

what are 3 general actions for PT's?

Back 83

treat - this person would benefit from PT

refer - what this person needs is outside the scope of PT, or i need more info before i decide if PT is appropriate for this patient

co-manage - i can do PT on this patient, and he can also benefit from OT

Front 84

pathology based model

Back 84

1. finding target disorder is holy grail
2. often initial step in process
3. commonly performed by direct access provider

Front 85

classification-based model

Back 85

1. finding relevant impairment/functional limitations is holy grail
2. often a later step in process
3. traditionally performed by rehab specialists

Front 86

what does diagnosis and classification provide?

Back 86

1. a means of communication with colleagues and consumers about conditions requiring the expertise of a PT
2. if we know what is wrong w/ a patient, we can pick an effective treatment and make a reliable prognosis

3. a grouping of conditions towards which research can be directed

Front 87

what are 4 strategies for diagnosis?

Back 87

1. pattern recognition
2. arboration
3. exhaustion
4. hypothetico-deductive

Front 88

definition of pattern recognition

Back 88

an instant realization that the patients looks like a previously learned picture or pattern of disease

its a reflexive strategy, often learned with experience, results in several, possible diagnoses, can be the start of other strategies

Front 89

arboration

Back 89

like trees, choose your own adventure

does the patient have pain the the leg? If yes, check strength and reflexes.

Are there changes in strength and reflexes? If yes, do this. if no, do that.

Front 90

exhaustion

Back 90

you find out everything you possible can about the patient, w/ no direction whatsover, and you try to figure out what is wrong after you collected all the information. not a good strategy for diagnosis

the invariant search, but paying no immediate attention to, for all medical facts about the patient, followed by sifting through the data for the diagnosis

collect data that might be pertinent = complete examination

NOT the right way

Front 91

hypothetico-deductive approach

Back 91

ask the right questions, and test the certain things. essential its a well directed way of getting history and selecting special tests.

start examination (history, systems review, tests and measures)

then formulate classification hypothesis ASAP.

Only collect data that is pertinent to the hypothesis

take home message: Make a hypothesis quickly after hearing initial complaint. Then selectively gather info that proves and disproves the hypothesis

Front 92

what do you need to do to maximize the efficiency and accuracy of diagnosis?

Back 92

find information that proves the hypothesis

find information that disproves the hypothesis

Front 93

quality of diagnostic studies

population

Back 93

demographic descriptors - age and sex

include those w/ suspected target disorder - type of disorder, severity of disorder, diagnostic dilemma

Front 94

quality of diagnostic study

the diagnostic test must be well ______ and _______

the diagnostic test must be compared to a _________

Back 94

described

repeatable

reference standard

Front 95

what is the definition of a reference standard?

Back 95

the gold standard

the result is accepted as the diagnosis

if the reference standard is not acceptable, then the study is invalid

Front 96

quality of diagnostic study

when you look at outcomes, you must look at the # of ______ and the # of _____

Back 96

CORRECT MATCHES (when reference standard and diagnostic tests agree aka both positive, or both negative)

INCORRECT MATCHES (one is positive, the other is negative)

Front 97

say you don't do a reference standard test b/c you get a negative diagnostic test result. what does this do?

Back 97

it eliminates information on negative

Front 98

definition of sensitivity

Back 98

the proportion of patients with the target disorder and a positive diagnostic test result

Front 99

what is the percentage that indicates high sensitivity?

how about high specificity?

Back 99

high sensitivity and specificity = greater than or equal to 93%

Front 100

positive LR's do give you an indication of what?

it is the ratio of what?

positive likelihood ratios are used to rule something ___

Back 100

the strength of a positive test finding

TP/FP

rule something in

Front 101

+ LR > 10

Back 101

large changes in post test odds

Front 102

+ LR 5-10

Back 102

moderate shift in post test odds

Front 103

+ LR 2-5

Back 103

small (sometimes important) changes in post test odds

Front 104

+ LR 1-2

Back 104

small, rarely important, changes in post-test odds

Front 105

In Ray's opinion, who is the cutest girl in UF DPT's class of 2011?

Back 105

Quadrant IV information.

Get back to work.

Front 106

definition of prognosis

Back 106

how well am I a going to do?

knowing how to estimate our patients likely clinical course (estimate what is going to happen to our patient) and anticipate likely complications of the disorder(anticipate what may go wrong)

Front 107

Determining the predicted optimal level of improvement in function and the amount of TIME needed to reach that level and may be reached at various intervals during the course of therapy

This is _____________

Back 107

prognosis

Front 108

prognosis influences these two things:
1.
2.

Back 108

1. The info we give to patients. "You are going to die soon."

2. How we act.
"Immediate treatment is necessary..."

Front 109

definition of prognostic factors

when are prognostic factors identified?

Back 109

specific factors associated with or predictive of outcome

prognostic factors are identified AFTER the target disorder is confirmed.

The target disorder is already developed. Prognostic factors influence the outcome of that target disorder

Ex: Lung cancer
Prognostic factor - weight loss (predictive of a poor outcome from lung cancer)

Front 110

definition of risk factors

Back 110

Target disorder is not yet developed

Risk factors influence the development of the target disorder.

Ex: lung cancer
Risk factor - smoking (leads to development of lung cancer)

Front 111

Natural history of disease
1.
2.
3.
4.

Back 111

1. Biologic onset
2. Early diagnosis possible
3. Usual clinical diagnosis
4. Clinical outcome

Prognosis focuses on the "clinical course" which is a subset of natural history of disease

Beginning - diagnosis
Ending - clinical outcome

Front 112

definition of critical point

where the critical points located?

Back 112

in the natural history of a disease, before which therapy is either more effective or easier to apply than afterward

Critical points alert clinicians to
1. times of enhanced treament effect
2. within the context of the natural history of the disease

between biologic onset, early diagnosis possible, usual clinical diagnosis, and outcome

Front 113

Prognosis - Qualitative aspect

what are the possible outcomes

ex: severe knee injury

Back 113

possible outcomes
1. Death (probably not)
2. Functional limitations (ambulation, stairs, recreational activities)

Front 114

Prognosis - quantitative aspect

How likely (what is the probability) that these outcomes will happen?

ex: severe knee injury

Back 114

Probability of happening:
death - less than .0001%
Functional limitations - near 100%

Front 115

Prognosis - temporal aspect

over what time period?

ex: severe knee injury

Back 115

Time period
death - less than .0001%, in the next 9-12 months

Functional limitations - nearly 100%, in the next 9-12 months.

Front 116

What three components contribute to prognosis?

Back 116

1. Qualitative (options, what may happen to you, death vs. functional limitations)

2. Quantitative (probability of each outcome happening to you)

3. Temporal (time)

Front 117

For example

Population of female high school basketball players, with confirmed ACL tears.

What are some examples of prognostic factors?

What are some examples of outcome?

Back 117

Prognostic factors
1. post-operative ROM
2. number of post-operative PT sessions

Outcomes
1. Return to playing basketball
2. 1 year after surgery

Take home message: You know that these girls have an ACL tear. Lets look at the prognostic factor post-op ROM. Look at the girls w/ low ROM post op, then look at their outcomes (play basketball after a year?) Then look at the girls who had high ROM post-op (did they play basketball after a year?)

Was there a difference in outcome?

Front 118

Is evidence about the accuracy of the prognostic factor valid?

important questions to ask yourself (4)

Back 118

1. did they have a well defined sample of patients?
2. did they have acceptable follow up rates (long enough and complete)?
3. Did they utilize objective outcome criteria?
4. Were subgroups appropriately considered?

Front 119

Is prognosis valid?

what is a well defined sample of patients? (important prognosis question #1)

what is the special name of this good sample called?

Back 119

A representative sample of patients assembled at a common, usually early point in the course of the disease.

These people got the disease at around the same time, and early in the progression of the disease.

Called an INCEPTION COHORT
You want an inception cohort.

Front 120

Is prognosis valid?

how do i know if follow up rates are acceptable? (important prognosis question #2)

Back 120

Patient follow up must be sufficiently long and complete.

If you lose a lot of patients, that may introduce bias.

Not acceptable - lose 20% or more patients to follow up

The concern is that patients w/ poorer outcomes may be less likely to complete the study

Front 121

is prognosis valid?

Were objective outcome criteria applied in a "blind" fashion? (important prognosis question #3)

Back 121

Easier for extreme outcomes - death
8 people died. 92 people lived.

Harder for middle of the road outcomes - improved function, return to work

Front 122

Prognosis valid?

how do you avoid outcome bias?

Back 122

establish objective criteria
1. before study starts
2. criteria supported by previous literature

Have blinded/masked person apply criteria

Front 123

prognosis valid?

subgroups appropriately considered?

Back 123

if subgroups w/ different prognoses are identified, was there an adjustment for important prognostic factors and validation in an independent group of "test set" patients?

subgroups has to make sense
initially only can make tentative conclusions

Front 124

percentage survival at a point in time

Back 124

1 year survival rate

Front 125

median survival

Back 125

length of time until 50% have had event

Front 126

survival distributions are often ________

Back 126

skewed

Front 127

statistical analysis w/ prognosis?

Back 127

multiple regression

Front 128

multiple regression

Back 128

one continuous outcome

Multiple potential prognostic factors
Crude = one considered at a time
Adjusted = all considered at same time

Generate regression (prediction) equation
Rsquared - estimate of total variance explained
Standardized and unstandardized coefficients

Front 129

regression quantifies 4 things

Back 129

1. Total variance (r-square) explained in outcome
2. Statistically significant prognostic factors
3. Relative contribution from one prognostic factor compared to another.
4. Prediction of outcome (generates a value)

Front 130

regression blah blah w/ crude estimates

Back 130

look at r-square. that tells you how one prognostic factor predicts an outcome in a certain amount of time.

for example:
prognostic factor - initial disability

outcome - disability at 4 weeks

Does initital disability predict disability at 4 weeks?
Look at R Square ( =.282)

Yes, initial disability predicts disability at 4 weeks, 28.2% (p=0.0005)

Front 131

multiple regression = one ________ outcome

Back 131

continuous

Front 132

logistic regression = one ________ outcome

Back 132

categorical outcome

generates ratios for outcome
-relative risk ratio
-odds ratio

Front 133

regression equation use _________ coefficient

Back 133

unstandardized

Front 134

y = constant + b1 (prognostic factor 1) + b2 (prognostic factor 2)

multiple regression. wtf do you do w/ this equation?

Back 134

Under "unstandardized coefficients"
look at the box that says "B" on top.

(Constant) = the first number
b1 = the second number
b2 = the third number

you will be given values for prognostic value 1 and 2, and just plug away.

Outcome = the number you get.

This card doesn't make sense to me either.

Front 135

chi-square analysis

signficant result p<0.05

what does this mean?

Back 135

prognostic factor has a BETTER THAN CHANCE ASSOCIATION with clinical outcome

Front 136

OR vs. RR

which is the gold standard?

why is it the gold standard?

Back 136

relative risk

1. cohort study design (prospective)
2. exposure status is known
3. all subjects followed forward
4. Outcome status is measured at later time

Front 137

RR is used for ______ studies

Back 137

cohort (prospective)

They had the prognostic factor, then look ahead at the outcome

They don't have to prognostic factor, then look ahead to look at the outcome

Front 138

cohort study and case control studies are both examples of _________ designs

Back 138

Quasi-experimental desgns

Front 139

how do you interpret RR?

example:
Prognostic factor - leg pain
disease - chronic lbp
RR = 4.6
interpret that

Back 139

RR estimates the likelihood of a disease given the presence of a prognostic factor

People with leg pain are 4.6 times more likely to develop chronic LBP

Front 140

so RR is the gold standard. why don't we use it all the time?

Back 140

1. expensive to follow entire population
2. Unrealistic to follow entire population
therefore RR calculation is not always feasible

Front 141

definition of odds ratio

Back 141

odds of exposure among individuals with outcome divided by the odds of exposure among individuals without outcome

Front 142

what is the classic study design for Odds Ration (OR)?

Back 142

case-control (retrospective)

subjects w/ disease are enrolled

subjects without disease are enrolled

Front 143

definition of recall bias

Back 143

systematic erro due to the differences in accuracy or completeness of recall to memory of past events or experiences.

ex: successes are more likely to recall treatment

Front 144

OR = 5.4

disease: chronic LBP
prognostic factor: leg pain
interpret that

OR estimates likelihood of _____ given _____

Back 144

you are talking about odds now. HENCE THE NAME. and you are also going backwards

Those with Chronic LBP have a 5.4:1 odds of having leg pain compared to those with normal LBP

You START with the outcome, then you follow backward to prognostic factor.

Therefore, OR estimates the likelihood of the prognostic factor given the outcome.

The outcome is given (chronic LBP). the OR tells us the likelihood of the prognostic factor.

Front 145

RR or OR > 1.0

Back 145

a risk or prognostic factor

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RR or OR = 1

Back 146

not a risk or prognostic factor

Front 147

RR or OR < 1

Back 147

a protective factor

Front 148

OR = RR happens when

case control study?

cohort study?

Back 148

Case control - factors selected independent of exposure status

cohort study - the overall incidence rate of the disease is low

Front 149

RR are good for _______ frequency of outcome

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LOW

Front 150

for prognostic factors

what if interval estimate of RR/OR contains 1.0?

Back 150

check lower bound of 95% CI

if it contains 1 or lower, then it may not be a prognostic factor

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for protective factors

what if the interval estimate of RR/OR contains 1.0?

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check the upper bound of 95% CI

if it is 1 or great, it may not be a protective factor

Front 152

______ indicates how precise the estimate (95% CI) is for the prognostic factor

Back 152

range