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difference between case-control and cohort study
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case-control: sample based on presence or absence of disease
cohort: subjects followed over time to see who gets the disease
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describe meta-analysis
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pooling data from several studies to get greater statistical power
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4 kinds of bias
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selection bias - nonrandom assignment
recall bias - knowledge of d/o alters recall
sampling bias - subjects not representative
late-look bias - info obtained at inappropriate time
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4 ways to reduce bias
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blind studies, placebo responses, crossover studies, randomization
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incidence x disease duration is approximately =
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prevalence
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high ___ for a screening test
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sensitivity
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high ____ for a confirmatory test
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specificity
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false negative rate =
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1 - Sn
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false positive rate =
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1 - Sp
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Sn vs. PPV
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Sn: number of TP divided by number of people with disease
a/(a+c)
PPV: number of TP divided by number of people who test (+) for disease
a/(a+b)
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specificity vs NPV
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sp: number of true (-) divided by # of people who don't have the disease
d/(b+d)
NPV: number of true (-) divided by # of people who test (-) for the disease
d/(c+d)
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OR used for ___ studies; RR used for ___ studies
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case-control; cohort
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How is OR calculated?
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ad/bc; number with disease divided by number w/o disease
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What does OR approximate if the prevalence of disease is not too high?
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RR
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How is RR calculated?
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a/(a+b) / c/(c+d);
number with disease divided by number in group
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random error vs systematic error
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random: reduced precision
systematic: reduced accuracy
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mean > median leads to ___ skew
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positive
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mean < median leads to ____ skew
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negative
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type I error
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to accept H1 when H0 is true; ie. stating there is an effect when none exists
alpha
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type II error
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to fail to reject H0 when H0 is false; ie stating there is NO effect when an effect DOES exist
beta
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probability of rejecting H0 when it is in fact false
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power
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what does power depend on?
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total number of end points, difference in compliance between treatment groups, size of expected effect
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SEM =
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sigma / sqrt n
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range of values in which a specified prob of means of repeated samples would be expected to fall
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confidence interval
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3 types of disease prevention
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primary - prevent disease occurence
secondary - early detection
tertiary - reduce disability
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preventive measure for homeless, recent immigrant, or inmate
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TB test.
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reportable diseases
|
B.A. S(3)M(2)ART Chicken or you're Gone:
Hep B
Hep A
Salmonella
Shigella
Syphilis
Measles
Mumps
AIDS
Rubella
TB
Chickenpox
Gonorrhea
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#1 leading causes of death in:
infants
1-14
15-24
25-64
65+
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infants: congenital anomalies
1-14: injuries
15-24: injuries
25-64: cancer
65+: heart disease
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informed consent requires:
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discussion of pertinent info (risks, benefits, alternatives)
patient's agreement
freedom from coercion
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4 exceptions to informed consent
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- waiver
- therapeutic privilege
- not legally competent
- implied consent (emergency)
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durable power of attorney
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pt designates surrogate to make decisions if pt loses decision-making capacity
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exceptions to confidentiality
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infectious diseases, Tarasoff decision, child and elder abuse, impaired auto drivers, homicidal/suicidal
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3D's for malpractice
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dereliction (breach of duty), damage, direct
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Situation: a child wishes to know more about his illness.
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Ask what parents have told child. Parents of child decide what info can be given.
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APGAR
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appearance (color)
pulse
grimace (reflex irritability)
activity (muscle tone)
respiration
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holds head up, Moro reflex disappears, social smile
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3 mo
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rolls front to back, sits when propped, recognizes people
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4-5 mo
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Sits alone, crawls, stranger anxiety, orients to voice
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7-9 mo
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upgoing Babinski disappears
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12-14 mo
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walks, few words, separation anxiety
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15 mo
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climbs stairs, stacks 3 blocks, object permanence
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12-24 mos
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stacks 6 blocks, rapprochement
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18-24 mos
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parallel play
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24-48 mos
|
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core gender identity
|
24-36 mos
|
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stacks 9 blocks, toilet training
|
30-36 mos
|
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rides tricycle, copies lines or circle drawing, group play
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3 years
|
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simple drawings (stick figure), hops on 1 foot, cooperative play, imaginery friends
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4 years
|
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reads; understands death, development of conscience, same-sex friends, identification with same-sex parent
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6-11 yrs
|
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abstract reasoning, formation of personality
|
11 yrs (girls), 13 yrs (boys)
|
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time period for normal bereavement
|
6 mos - 1 year
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