Behavioral science

Question 1

Lead-time bias

Answer 1

prolonged survival in patients with screening test

- Earlier diagnosis without improved prognosis

Question 2

Recall bias

Answer 2

Inaccurate patient recall of past exposure

- ex: what caused cancer?

Question 3

Observer bias

Answer 3

Investigator decision changed by prior knowledge of exposure status

Question 4

Type 1 error

Answer 4

Reject null hypothesis when it’s true

- Found a difference when there isn’t one)

Question 5

P-value

Answer 5

Probability of making type 1 error

- Accepted at P< 0.05 (5% chance)

Question 6

Type 2 error

Answer 6

Failure to reject null hypothesis when it’s false

Question 7

Beta

Answer 7

Probability of making a type 2 error

Question 8

Power

Answer 8

1- beta

ex: beta= 20% chance of making type 2 error;
- power= 80% chance of rejecting truly false null hypothesis

Question 9

Case-control study

Answer 9

Compares those with disease to those without disease
- Measures Odds Ratio (OR):
(exposed with disease/diseased)/ (exposed without disease/ all without disease)

Question 10

Cohort study

Answer 10

Compares group with exposure/risk factor to group without exposure
- Measures relative risk (RR):
Risk of disease with exposure/ risk of disease without exposure

Question 11

Clinical trial phases

Answer 11

Phase I= safety, toxicity, PK
Phase II= efficacy, dosing, AEs
Phase III= comparison to standard tx
Phase IV= rare, long-term AE (post-marketing)

Question 12

Case-fatality rate

Answer 12

Fatal/ (Fatal + nonfatal cases)

Question 13

Sensitivity

Answer 13

Test detects disease when disease present
- Screening tool for disease with low prevalence

True positives / (TP + False negatives)

Question 14

Specificity

Answer 14

Test indicates non-disease when disease is absent (ruling in disease)
- Confirmatory test after positive screen

True negatives/ (TN + False positives)

Question 15

Positive predictive value

Answer 15

Proportion of positive test results that are truly positive: TP/ (TP+ FP)

Question 16

Negative predictive value

Answer 16

Proportion of negative results that are truly negative

TN/ (FN + TN)

Question 17

Attributable risk

Answer 17

How much disease was due to exposure?

Disease rate with exposure / disease rate without exposure
- Ex: 21% lung cancer risk in smokers, 1% in non-smokers= 20% attributable risk

OR:
Adverse Event rate (tx) - Adverse event (placebo)

Question 18

Absolute risk reduction

Answer 18

Event rate (control) - Event rate (treatment group)

Question 19

Number needed to treat

Answer 19

Number to treat for 1 patient to benefit:
1/(absolute risk reduction)

ARR= event rate (control)- Event rate (treatment group)

Question 20

Number needed to harm

Answer 20

Number needed to treat for 1 patient to have adverse event:

1/ (attributable risk)

Question 21

Late-look bias

Answer 21

information gathered at inappropriate time (ex: survey to study fatal disease after people will have died of disease)

Question 22

Procedure bias

Answer 22

Subjects in different groups not treated the same

more attention paid to tx group

Question 23

Observer-expectancy effecct

Answer 23

Researcher’s belief in efficacy of treatment changes outcome of treatment

Question 24

Hawthorne effect

Answer 24

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

Question 25

Standard error of the mean (SEM)

Answer 25

SD/ square root (sample size) - SEM is powered by the size of the population - Larger study indicates the standard deviation is closer to what would be seen in the general population

Question 26

Positive skew

Answer 26

Mean skewed positively: | - Mean > Median > mode

Question 27

Negative skew

Answer 27

Mean skewed negatively | - Mean < Median < mode

Question 28

Confidence interval

Answer 28

Range from [mean- Z(SEM)] to [mean + Z(SEM)] 95% CI for a mean difference including 0--> H0 is not rejected 95% CI for a OR or RR including 1, H0 is not rejected - H0= null hypothesis - H1= alternative hypothesis 95% CI; Z=1.96 99% CI; Z= 2.58

Question 29

T-test

Answer 29

Difference between means of 2 groups 2-sample T-test= determine if means of 2 populations are equal: need: - 2 mean values - Sample difference (standard deviation) - Sample size

Question 30

ANOVA

Answer 30

Analysis of variance | - Checks difference between mean of 3+ groups

Question 31

Chi-square

Answer 31

Difference between 2+ percentages or proportions (NOT mean values) x^2= compare percentages/proportions

Question 32

Multiple linear regression

Answer 32

Model linear relationship between dependent variable and 2+ independent variables ex: alcohol and tobacco use and incidence of gastric cancer

Question 33

Pearson's correlation coefficient (r)

Answer 33

Measures strength of linear regression line (closer value is to r, stronger linear correlation) Ranges between -1 and 1 (depending on direct(+) or inverse(-) relationship between two factors

Question 34

Apgar score

Answer 34

``` Assess newborn vital signs via 10-point scale at 1 and 5 minutes Appearance Pulse Grimace Activity Respiration ``` >= 7: good 4-6: assist, stimulate < 4: resuscitate * * Low birth weight < 2500 g - Premature, intrauterine growth retardation - Increased risk of SIDS, mortality, developmental problems

Question 35

Birth-3 months milestones

Answer 35

Motor: - Rooting reflex - Hold head up - Moro reflex disappears Social: - Social smile Verbal/cog: - Orients, responds to voices

Question 36

7-9 months

Answer 36

Motor: - sits alone, crawls - Transfers toys from hand to hand Social: - stranger anxiety Verbal/cog: - Responds to name, simple instructions - Uses gestures, plays peek-a-boo

Question 37

12-15 months

Answer 37

Motor: - walks - Babinski sign gone Social: - Separation anxiety Verbal/cog: - Few words

Question 38

12-24 months

Answer 38

Motor: - climbs stairs - stacks 3 blocks at 1 year, 6 at 2 (3/year) Social: - Rapprochement (moves away from, returns to mother) Verbal/cog: - 200 words and 2-word phrases

Question 39

24-36 months

Answer 39

Motor: - Feeding self with fork and spoon - Kicks ball Social: - Core gender identity, parallel play Verbal/cog: - toilet training

Question 40

3 years

Answer 40

Motor: - Rides Tricycle - Copies line, circle drawings Social: - Comfortably spends part of day away from mom Verbal/cog: - 900 words, complete sentences

Question 41

4 years

Answer 41

Motor: - Uses buttons, zippers, grooms self (brush teeth) - Hops on 1 foot - Makes simple drawings Social: - Cooperative play, imaginary friends Verbal/cog: - Detailed story telling, uses prepositions

Question 42

Circadian rhythm

Answer 42

``` Suprachiasmatic nucleus (SCN) of hypothalamus - Controls ACTH, prolactin, melatonin, nocturnal NE release ``` SCN--> NE release--> pineal gland--> melatonin SCN regulated by environment (light)