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Flashcards in Epidemiology and ethics 1 Deck (54):
1

Case fatality rate

percentage of people with a given disease who die within a certain amount of time

2

birth rate

live births per 1000

3

fertility rate

live births per 1000
of women aged 15-45 years

4

death rate

deaths/1000

5

neonatal mortality rate

neonatal deaths (first 28 days of life)/10000 live births

6

perinatal mortality rate

neonatal deaths+ stillbirths/1000 total births

7

infant mortality rate

deaths (from 0-1 yo)/1000 live births

8

maternal mortality rate

maternal pregnancy-related deaths (deaths while pregnant or in the first 42 days after delivery)/100,000 live births

9

relative risk

probability of getting disease in group that is exposed to risk factor, compared to (divided by) probability of getting that disease in people who are unexposed

A/(A+B)/C(C+D)

RR>1 positive disease
RR

10

Odds ratio

A/C divided by B/D

11

Attributable risk

difference in risk between exposed and unexposed
A/(A+B)- C/(C+D)

12

Absolute risk reduction

Conceptually similar to calculation of attributable risk, but opposute

C/(C+D)-A/(A+B)

13

NNT

1/ARR
The number of patients you would need to treat in order to save/affect one life

important to determine if a drug should be used or is cost effective

14

Sensitivity

Probability that a screening test will be positive in patients with a disease
A/(A+C)

15

Specificity

D/(B+D)

false positive rate= 1-specificity

16

PPV

PPV= A/(A+B)

what's the value of the positive test result? likelihood that the person will be positive if they have tested positive

17

NPV

NPV= D/(C+D)

high prevalence gives high positive predictive value

low prevalence gives high negative predictive value

18

Likelihood ratio

does not depend on prevalence

odds of having a positive test result in individuals with a disease, compared with the odds of a positive result in those without the disease

(the positive person should test positive)

PLR= sensitivity/1-specificity
or sensitivity/false pos rate

NLR= 1-sensitivity/specificity
or false neg rate/specificity

19

Negative likelihood ratio

odds of having a negative test result in individuals with a disease compared with the odds of a negative result in those without the disease

NLR= 1-sensitivity/specificity
or false neg rate/specificity

PLR= sensitivity/1-specificity
or sensitivity/false pos rate

20

Accuracy

correct/true results

true pos/true neg/everything

21

Type i error

rejects null even though it's true

22

Type II error

null hypothesis rejected even though it is false

beta error

23

Statistical significance

statistically detectable difference between 2 groups (not the same as clinical significance)

measured by the arbitraty p value

24

power

ability of study to detect a difference between 2 groups

25

Confidence interval

range of values in which the examiner can be (90,95, 99%) confident that the value obtained from the study truly reflects reality

ranges from
[mean-z(SEM)] to
[mean+z(SEM)]

z= 1.645 for 90%
1.96 for 95%
2.57 for 99%

if CI crosses 1, no relationship
if CI for 2 treatment groups crosses 0, there may be no difference between the 2 groups

26

What's important in a screening test? in a confirmatory test?

sensitivity for screening (Catch everybody)
specificity for confirmation (eliminate false pos)

27

what percentage falls within 1,2,3 sd's of the mean in a normal distribution?

68,95,99.7%

28

DMAIC for quality improvement

Define the problem
Measure: establish an objective baseline
Analyze- identify causes of the problem
Improve- identify and implement interventions (re-measure, re-analyze, and re-intervene as needed)
Control- maintain the improvement that you achieved

29

Identifies 2 groups: diseased group and healthy group. Retrospectively compares them. Weakened by recall and selection biases

case- control study

30

Seeks to estimate disease prevalence and exposure across a population

cross- sectional study

31

examines a collection of studies on a given subject

meta-analysis

32

prospective blinded study involving placebos, existing therapies, and experimental interventions

RCT

33

Focuses on ONE group with a shared exposure or disease and either prospectively or retrospectively compares them

cohort study

34

examines a collection of cases to seek insight into the disease of interest. Useful in rare diseases

case control

35

Memory errors produce incorrect data

recall bias

36

subject awareness of being studied alerts their answers and behaviors from normal

observational bias

37

certain medical studies attract subjects with particular medical histories rather than general population

selection bias

38

studies that show a difference are preferentially published and then later included in meta- analysis rather than studies that support the null hypothesis

publication bias

39

screening tests designed to detect asymptomatic disease may miss rapidly- progressive disease because the interval between successive screenings only detects slowly- progressive ones

length bias

40

screening test may allow earlier diagnosis of disease but does not translate into actual length of survival

Lead- time bias

41

exemptions from condifentiality

-patient allows physician to share information
-disease is legally reportable (HIV, STD, hepatitis, Lyne, door-borne, meningitis, rabies, TB, impaired ability to drive, child abuse, elder abuse)
-patient is suicidal or homicidal
-penetrating wound from an assault
-adolescent with a condition that is harmful to self or others

maintain adolescent confidentiality if pertaining to with STDs, pregnancy, or contraception

42

Informed consent

potential risks and benefits of proposed treatment
alternative treatments
risks of refusing treatment

pt can always change their mind

not required in an emergency

43

Capacity

patient has the mental ability to make decisions regarding his or her medical care

Competence is a legal thing

44

Competence- legalities

not psychotic or intoxicated
have understanding of medical situation
capable of making decisions

45

medical decisions by parents on behalf of minors may be legally overruled it...

considered harmful to the child

in an emergency, treat the patient despite the parents' wishes and get the court order later

46

Durable power of attorney

designates a surrogate decision maker

makes decisions consistent with the patient's values

"substituted judgment"

47

Living will

written document that details a patient's wishes about specific medical situations

out of hospital DNR order

advance directive

48

Physician- assisted suicide

physician supplies patient with means of ending his or her life
-Oregon
-Washington
-Vermont
-Montana (exceptions)
-Canada

49

Euthanasia

physician actively ADMINISTERS lethal agent to patient, to end suffering

This is illegal in the US

50

Brain death

-irreversible absence of all brain activity
->6 hrs
-absence of cranial nerve reflexes
-apnea
-absence of brainstem- evoked responses, absence of cerebral circulation, or persistent isoelectric EEG
-Cannot be explained by a medical condition that mimics death (encephalopathy, hypothermia, intoxication, locked-in syndrome, Guillain-Barre syndrome)

51

Medical malpractice

Duty of care (legal obligation to conform to a reasonable standard of care)
breach of duty (failure to conform to the standard of care)
harm
causation (breach of duty is the cause of injury or harm)

52

What are the 2 ways that "standard of care" can be established in a malpractice case?

1. expert testimony
2. Res ipsa loquitur "it speaks for itself" doctrine

53

Vicarious liability principle

supervisors are responsible for the actions of their subordinates

54

When can a physician refuse to treat a patient on the grounds of futility?

1. no rationale for treatment
2. maximal intervention has already failed
3. treatment does not achieve the goals of care