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Flashcards in Behavioral Sciences Deck (109):
1

Relative Risk
Equation
When is it used?
What is it?

[a/(a+b)]/[c/(c+d)]
Cohort Studies
(Risk of developing disease in exposed group)/(risk in unexposed group)

2

Odds Ratio
Equation
When is it used?
What is it?

ad/bc
Case-Control Studies
Odds that the group with the disease was exposed to risk factor (a/c)/(Odds that the group without disease was exposed (b/d)

3

Observer Bias

Investigator is affected by prior knowledge

4

Confounding

Exposure-disease relationship can be explained by another variable

5

Lead-Time Bias

Apparent prolongation of survival because of earlier diagnosis

6

Recall Bias

Inaccurate pt recall

7

Selection Bias

Subjects selected biasedly or biased from selective loss of follow up

8

Case Control Study
Mode of investigation
Timeframe
Design
Basic Question
Measurement

Observational
Retrospective
Compare groups of people w/ and w/o disease and look for prior exposure or risk factors
"What Happened?"
Odds Ratio

9

Cohort Study
Mode of investigation
Timeframe
Design
Basic Question
Measurement

Observational
Prospective or Retrospective
Compare a group with a given exposure or risk factor to a group w/o it and look if exposure ↑ likelihood
Who will or Who has developed disease
Relative Risk

10

Cross Sectional Study
Mode of investigation
Timeframe
Design
Basic Question
Measurement

Observational
Right Now
Collect data from a group of people to assess frequency of disease and relative risk at a particular point in time
"What is happening?"
Prevalence, Relative Risk, Can show Risk Factor Association but not causality

11

Twin Concordance Study
Design
Measurements

Compares frequency with which monozygotic or dizygotic twins develop the same disease
Measures Heritability

12

Adoption Study
Design
Measurements

Compares siblings raised by biological vs adoptive parents
Heritability and influence of environmental factors

13

Clinical Trial
Population involved
Design
What improves study

Experimental study involving humans
Compares therapeutic benefits of 2 or more treatments or treatment and placebo
Randomized, Controlled, and Double Blinded studies are better

14

Double vs Triple Blind

Double: Patients and Doctors do not know whose getting treatment
Triple: Researchers analyzing data do not know who got treatment

15

Phase I Clinical Trial
Sample
Purpose

Small # of health volunteers
Assesses safety, toxicity, and pharmacokinetics

16

Phase II Clinical Trial
Sample
Purpose

Small # of patients w/ disease
Assesses treatment efficacy, optimal dosing, and adverse effects

17

Phase III Clinical Trial
Sample
Purpose

Large # of patients comparing 2 drugs or placebo
Compares new treatment to current treatment

18

Phase IV Clinical Trial
Sample
Purpose

Postmarketing surveillance trial of patients after approval
Detects rare or long term adverse effects

19

Sensitivity
Rate of what?
Formula (2)
Purpose
Use

"SNOUT - SeNsitivity rules OUT"
"PID - Positive In Disease"
True Positive Rate
a/(a+c) = 1-(false neg rate)
Rules out disease
Used for screening in diseases w/ low prevalence

20

Specificity
Rate of what?
Formula (2)
Purpose
Use

"SPIN - SPecificity rules IN"
"NIH - Negative In Health"
True Negative Rate
d/(d+b) = 1-(false pos rate)
Rules in disease
Confirmatory test after positive screening test

21

Positive Predictive Value
What does it show?
Formula
What does it vary with?

Proportion of + tests that are true positives
a/(a+b)
Varies directly with prevalence or pretest probability: high pretest probability --> high PPV

22

Negative Predictive Value
What does it show?
Formula
What does it vary with?

Proportion of negative test results that are true negative
d/(c+d)
Varies inversely with prevalence or pretest probability: High pretest probability --> low NPV

23

Incidents

(New cases over specified period)/(Population at risk)

24

Prevalence Equations (2)

(Existing cases)/(Population at risk)
Incidence x Average disease duration

25

Prevalence vs Incidence in chronic disease

Prevalence > Incidence

26

When are RR and OR equal?

When prevalence is low

27

Attributable Risk
Equation
What is it?

[a/(a+b)]-[c/(c+d)]
Risk in exposed group - Risk in unexposed group

28

Absolute Risk Reduction (ARR)
What is it?

c/(c+d) - a/(a+b)
Event rate in placebo minus treatment groups

29

Number Needed to Treat
What is it?
Equation

Number of pts who need to be treated for 1 patient to benefit
1/(absolute risk)

30

Number Needed to Harm
What is it?
Equation

Number of pts who need to exposed to a risk factor for 1 pt to be harmed
1/(attributable risk)

31

Precision
What is it?
What reduced precision?
When precision is increased, what happens?

Consistency and reproducibility of a test. The absence of random variation
Random error ↓ precision
↑ precision --> ↓ SD

32

Accuracy
What is it?
What kind of error does it measure?
What reduces accuracy?

Trueness of test measurements (validity)
Absence of systematic error or bias in the test
Systemic error ↓ accuracy

33

Sampling bias

Subjects not representative of the general population
A form of selection bias

34

Late-Look Bias

Information gathering at an inappropriate time (i.e. survey to study a fatal disease - only those still alive will be able to answer survey)

35

Procedure Bias

Subjects in different groups are not treated the same way

36

Hawthorne effect

Group being studied changes behavior because they know they are being studied

37

In a normal distribution, how do measurements of central tendency relate?

Mean = Median = Mode

38

Standard Deviation
What roman numeral?
Percentages?

σ
(+1σ) and (-1σ) account for 68% of n
(-2σ) to (+2σ) account for 95% of n
(-3σ) to (+3σ) account for 99.7% of n

39

SEM
What is it?
How does it vary?

σ/√n
SEM will ↓ as n ↑

40

Positive Skew
How do measurements of central tendency relate?
Which is least affected?
How does graph look?

Mean > Median > Mode
Mode is least affected by outliers in the sample
Asymmetrical distribution with long tail on right

41

Negative Skew
How do measurements of central tendency relate?
How does graph look?

Mean < Median < Mode
Asymmetry with longer tail on left

42

Statistical Hypotheses
Null Hypothesis
Alternative Hypothesis

There is no association between the disease and the risk factors (H0)
There is some association between the disease and the risk factor (H1)

43

Type I error
Symbol
What is it?
AKA
What is used to calculate it?

α
Error of stating there is a difference when there is not. Accepting H1 and rejecting H0 when H0 is true.
False-Positive Error
Used to calculate p

44

Type II error
Symbol
What is it?
AKA

β
Error that there is not an effect or difference when one exists. Accept H0 when H1 is true
False-Negative Error

45

Power
Equation
What is it?
What increases it?

1-β
Probability of rejecting H0 when it is false
Increases with ↑ Sample Size, Expected Effect Size, and Precision of measurements

46

Meta Analysis
What is it?
What does it increase?
What limits it?

Pools data and integrates results from several similar studies
↑ statistical power
Limited by quality of individual studies or bias in each study

47

Confidence Interval
Equation
Conventions of CI
How does it relate to Z

Range of values in which a specified probability of the means of repeated samples would be expected to fall
Range from [mean - Z(SEM)] to [mean + Z(SEM)]
95% CI corresponds to p=.05
CI = 95%, Z = 1.96
CI = 99%, Z = 2.58

48

If the 95% CI for a mean difference between 2 variables includes 0?

There is no significant difference and H0 is accepted

49

If the 95% CI for OR or RR includes 1...

H0 is not rejected

50

If the CIs between 2 groups do not overlap...

Significant difference exists

51

If the CIs between 2 groups overlap...

No significant difference

52

t-test

Checks differences between the means of 2 groups

53

ANOVA

Checks difference between the means of 3 or more groups

54

χ2

Test checks difference between 2 or more percentages or proportions of categorical outcomes (not mean values)

55

Pearson's Correlation Coefficient
Symbol?
What is its range?
What does it measure

r
-1 to +1
The closer it is to 1, the stronger the linear correlation between 2 variables

56

Coefficient of determination

r^2

57

Disease Prevention
Primary
Secondary
Tertiary

"PDR"
Prevent occurrence
early Detection
Reduce disability from disease

58

Medicare

For the Elderly (≥65)

59

Medicaid

For the Destitute

60

Autonomy

Respect pt as individuals and honor their preferences

61

Beneficence

Fiduciary duty to act in patient's best interests

62

Nonmaleficence

Do no harm

63

Justice

Treat persons fairly

64

When is parental consent not necessary?

Emancipated (married, self supporting, has children, in the military), Emergency, Contraception, Treating STDs, Pregnancy, Treatment of Drug Addiction

65

Can the patient's family require that a doctor withhold information from a patient?

Not if the patient demonstrates decision making capacity

66

Exceptions to confidentiality

Harm to others, harm to self, and physician can prevent harm

67

A 17 year old girl is pregnant and requests an abortion

Many states require parental notification or consent for minors for an abortion. Unless she is at medical risk, do not advise pt to have an abortion regardless of her age or condition of the fetus

68

A terminally ill pt requests physician assisted suicide

No Way! but can give medically appropriate analgesics that coincidentally shorten the pt's life

69

Suicidal patient

Patient can be hospitalized involuntarily

70

Patient says she feels ugly

Do not offer falsely reassuring statements like "you still look good"

71

Patient is angry about the wait time

Do not explain delay. Just apologize and acknowledge

72

Referral fees for study inclusion

Must tell patient

73

Patient is upset with how another doctor treated them?

Suggest the pt speak directly with the doctor

74

Patient is upset with how they were treated by office staff

Say you will speak with that person

75

APGAR score
Time
What is it?
What do scores mean?
What if the score is low?

1 minute and 10 minutes
Appearance, Pulse, Grimace, Activity, Respiration
Greater than or Equal to 7 is good.
4-6: assist and stimulate
Less than 4: resuscitate
If <4, there is ↑ risk of long term neurological damage

76

Low Birth Weight
Definition
What causes it?
Increased risk for what?
Other problems?
Complications?

Less than 2500g
Prematurity or intrauterine growth retardation
"PREME C SHIT"
↑ risk for SIDS and overall mortality
Impaired thermoregulation and immune function, Hypoglycemia, Polycythemia, Impaired neurocognitive/emotional development
Infections, RDS, Necrotizing enterocolitis, Intraventricular hemorrhage, persistent fetal circulation

77

Birth to 3 months
Motor
Social
Cognitive

Rooting reflex, holds head up, Moro reflex disappears
Social smile
Orients and responds to voice

78

7 to 9 months
Motor
Social
Cognitive

Sits alone, Crawls, Transfers toys from hand to hand
Stranger anxiety
Responds to name and simple instructions, uses gestures, plays peek-a-boo

79

12 to 15 months
Motor
Social
Cognitive

Walks, Babinsky Sign Disappears
Separation anxiety
Few words

80

12 to 24 months
Motor
Social
Cognitive

Climbs stairs, Stacks 3 blocks at 1 year, Stacks 6 blocks at 2 years
Rapprochement
200 words. 2 word phrases at age 2

81

24 to 36 months
Motor
Social
Cognitive

Feeds self with fork and spoon. Kicks ball
Core gender identity. Parallel play
Toilet training (pee at 3)

82

3 years old
Motor
Social
Cognitive

Rides tricycle (3 cycle at 3). Copies line or circle drawings
Comfortably spends part of the day away from mother
900 words. Complete sentences

83

4 years
Motor
Social
Cognitive

Uses buttons and zippers, Grooms self, Hops on 1 foot, Makes simple drawings
Cooperative play, Imaginary friends
Can tell detailed stories and uses prepositions.

84

Sexual changes in the elderly

Interest does not ↓
Men have slower erection, ejaculation, longer refractory period
Women have vaginal shortening, thinning and dryness

85

Intelligence changes in the elderly

Intelligence does not decrease

86

How age changes sleep patterns

↓ REM and slow-wave sleep. ↑ latency and awakening

87

Psychological changes in the elderly

↑ suicide rates
Men 65-74 have highest rates in US

88

Organ system changes with age

↓ Vision, Hearing, Immune response, Bladder control, Renal, Pulmonary, GI
↓ muscle, ↑ fat

89

Grief
What is it characterized by
Length

Shock, Denial, Guilt, Somatic symptoms. May experience illusions
Up to 1 year

90

Pathologic Grief
What is it?
What may they experience

Excessive, prolonged (>1 year), delayed, inhibited, or denied grief
May experience depression, delusions, and hallucinations

91

Sexual Dysfunction DDx

Drugs, Disease (depression, diabetes), Psychological

92

BMI
Formula
#s

(Wt in kg)/(Height in meters)^2
Less than 18.5 is underweight
25 to 29.9 is overweight
Greater than 30 is obese

93

Awake with Eyes Open
Description
EEG

Alert and active
Beta (highest frequency, lowest amplitude)

94

Awake with Eyes Closed
EEG

Alpha

95

Stage N1 sleep
Percent of sleep
Description
EEG

5%
Light Sleep
Theta

96

Stage N2
Percent of sleep
Description
EEG

45%
Deeper sleep; Bruxism
Sleep Spindles and K complexes

97

Stage N3
Percent of sleep
Description
EEG
What can happen during this stage?

25%
Deepest non REM sleep
Delta waves (low frequency, high amplitude). Slow wave sleep
Sleepwalking, night terrors, bedwetting

98

REM sleep
Percent of sleep
Description
EEG

25%
Dreaming, Loss of motor tone, Memory processing, Erections, ↑ brain O2 use
Beta waves

99

EEG waveforms in sleep

"BATS Drink Blood"
Beta, Alpha, Theta, Sleep spindles, Delta, Beta

100

Brain region in initiating sleep

5HT region of Raphe Nucleus

101

Treatment for Sleep Enuresis

Oral Desmopressin
Preferred over Imipramine

102

Drugs that reduce REM sleep?

EtOH, Benzodiazepines, Barbituates
Also reduce Delta sleep

103

Treatment for night terrors and sleepwalking?

Benzodiazepines

104

REM sleep
When does it occur?
Duration
Change with age?
Neurotransmitters involved
Findings

Every 90 minutes
Duration ↑ throughout night
↓ frequency with age
ACh --> REM. NE --/ REM
↑ and variable BP and HR. EOM (activity of PPRF), Penile/Clitoral Tumescence

105

Sleep patterns of depressed patients

↓ slow wave sleep, REM latency,
↑ REM early in sleep, ↑ total REM sleep
Repeated nighttime awakening
Early-morning awakening

106

Narcolepsy
What is it?
Presentation
Sleep cycle
Genetics
Treatment

Disordered regulation of sleep-wake cycles
Daytime sleepiness, Hallucinations (right before or after sleep), Cataplexy following strong emotional stimulus. Cannot move when you wake up in the morning
REM at beginning of sleep
Strong genetic components
Daytime stimulants (amphetamines, modafinil) and nighttime GHB (sodium oxybate)

107

Circadian Rhythm
Brain centers involved
What does it control
Pathway

Suprachiasmatic nucleus (SCN) of the hypothalamus
Controls ACTH, Prolactin, Melatonin, and nocturnal NE release
SNC --> NE release --> Pineal gland --> melatonin

108

SCN regulation

SCN regulated by environment (light)

109

Sleep Terror Disorder
What is it?
When does it occur?
Population involved
Memory
Cause
Course

Periods of terror with screaming in the middle of the night
Slow-wave, non-REM sleep
Children
No memory of event
emotional distress, fever, lack of sleep
Self limited