Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Epidemiology For Public Health > Module 3 > Flashcards

Module 3 Flashcards

Rothman Module 3, Lecture 3

1
Q

What is the Likert Scale?

A

In its final form, the Likert scale is a five (or seven) point scale that is used to allow an individual to express how much they agree or disagree with a particular statement.

It is controversial in its unobjective and forced responses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is nominal data?

A

categorical / qualitative data; categories as values which differ in quality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is ordinal data?

A

Nominal data that are ordered in some way (good, better, best / small, medium, large / 1,2,3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is interval data?

A

There is a meaningful and definable distance between the categories of measurement. There is no fixed relationship to zero.

(e.g. temperature - 100 is 10 degrees more than 90, but 100 is not twice as hot as 50; 0 also does not represent the “absence” of temperature)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is ratio data?

A

Has all the properties of interval data, but there is a meaningful relationship to zero

(e.g. height, weight, enzyme activity, bacterial counts…. someone who weighs 200 pounds weights twice as much as someone who weighs 100 pounds).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a ratio?

A

The size of something compared to the size of something else; a/b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a rate?

A

(a+b) / time ; the change in a subset compared to the change in the set per unit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the most commonly used rate in epidemiology?

A

incidence - events (a) per person (b) per time (t) = a/b/t or a/bt

e.g. 10 people are observed for 10 years (100 person years).. 6 get heart attacks. The incidence of heart attacks in this group is 6 per person years.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a proportion?

A

the size of a part relative to the whole (a/a+b)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the cumulative incidence / proportion?

A

the number who moved into the numerator (na) divided by the total number of people at the beginning (b) minus the ones who left the denominator; na/(b-na)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the numerator and denominator in relation to incidence?

A

Events in the numerator are things (infections) that happen to people in the denominator. That means when an event occurs, people are moved from denominator to numerator. Both will change - the numerator gets bigger and the denominator smaller.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the difference between incidence and prevalence?

A

Incidence is answering the question: “how fast is something occurring?”

Prevalence is concerned with the question: “how much is there at some point in time?”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is point / period prevalence?

A

numbers of cases per population at some instant. This is usually impossible to measure, so the term “Period Prevalence” is used.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the relationship of prevalence, incidence, and duration?

A

Prevalence = Incidence x Duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do we determine the difference between groups in research?

A

the size of the difference (count)
the dispersion of the data (a ratio)
the number of observations used to determine the point data / sample size (count)

The larger the sample, the more likely you are coming closer to a true number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Who first referred to the “Distribution around the mean”?

A

Carl Friedrich Gauss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is normal distribution / distribution around the mean?

A

Normal distribution, also known as the Gaussian distribution, is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean. In graphical form, the normal distribution appears as a “bell curve”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a Z score?

A

Z-score is a statistical measurement that describes a value’s relationship to the mean of a group of values.

The higher (or lower) a z-score is, the further away from the mean the point is.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a standard deviation?

A

The standard deviation is the average amount of variability in your dataset. It tells you, on average, how far each value lies from the mean.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a t test?

A

A t test is a statistical test that is used to compare the means of two groups. It is often used in hypothesis testing to determine whether a process or treatment actually has an effect on the population of interest, or whether two groups are different from one another.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the ultimate goal of validating research outcomes?

A

To achieve generalizability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is an odds ratio?

A

It is a measure of association between an exposure and an outcome

As an example, if the odds ratio is 1.5, the odds of disease after being exposed are 1.5 times greater than the odds of disease if you were not exposed another way to think of it is that there is a 50% increase in the odds of disease if you are exposed.

Here it is in plain language. An OR of 1.2 means there is a 20% increase in the odds of an outcome with a given exposure. An OR of 2 means there is a 100% increase in the odds of an outcome with a given exposure. Or this could be stated that there is a doubling of the odds of the outcome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is accuracy versus precision?

A

Precision and accuracy are two ways that scientists think about error. Accuracy refers to how close a measurement is to the true or accepted value. Precision refers to how close measurements of the same item are to each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is validity in research?

A

how well the results among the study participants represent true findings among similar individuals outside the study.

The term validity refers to the correctness of the conclusions that are drawn from the results. In other words, how accurate are the results? Do the results actually measure what was intended to be measured? It is important to assess if a study was conducted so that each of its elements is defensible, and their interaction produced a coherent “story” with regard to the findings.
Threats to validity include: (1) measurement error—the exposure and the outcome were measured correctly; (2) misclassification—either persons or exposures were placed in the wrong categories; (3) bias—non-systematic mistakes (different for cases and control in a study) that distort the results; (4) incorrect or inappropriate analytic procedures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is reliability in research?

A

Reliability refers to how consistently a method measures something. If the same result can be consistently achieved by using the same methods under the same circumstances, the measurement is considered reliable.

Test & retest in different circumstances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is falsifiability in research?

A

Falsifiability is a cornerstone of the scientific method. It refers to the idea that, to be a valid scientific hypothesis, it must be possible to disprove it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is generalizability in research?

A

Generalizability refers to whether or not the research findings and conclusions that result from the study are applicable to other populations or, more broadly, to everyone.

The Framingham Heart Study (which utilized only white men) is a great example of what NOT to do

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Are the following examples a rate, ratio, count, or proportion?

  1. Components of a recipe for chocolate cake
  2. The prevalence of tuberculosis
  3. The speed of light
  4. Infant mortality (per live births)
  5. Ears of corn produced per acre cultivated
  6. Cases of flu seen in a clinic per month
A
  1. Count
  2. Proportion
  3. Rate
  4. Ratio
  5. Rate
  6. Proportion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the epidemiologic triangle?

A

Agent, host, and environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are different types of infectious agents?

A

Biological Microorganisms, Pathogens, such as :
Bacteria, viruses, rickettsia, fungi and yeast, Helminthes, Protozoans, Prions

Chemical:
poison, alcohol, smoke

Physical:
trauma, radiation, fire

Nutrition:
lack, excess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are environmental factors associated with increased risk of disease?

A

temperature
air pollution
crowding
neighborhood
sanitation
healthcare access
vector control (of certain animals e.g. birds or mosquitos)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are host characteristics associated with increased risk of disease?

A

Age
sex
cultural practices
Socio economic status

33
Q

What is infectivity?

A

ability to establish infection in an exposed person

34
Q

What is pathogenicity?

A

ability to cause disease in infected person

35
Q

What is virulence?

A

how sick an infected person gets

36
Q

What is a host and its risk factors?

A

An organism (usually human or animal) that harbors a disease

Risk factors: exposure, susceptibility, response

37
Q

What is an environment in epidemiology?

A

surroundings / conditions external to the human or animal (host) that cause or allow disease transmission

38
Q

What are reservoirs?

A

The habitat (living or nonliving) on which an infectious agent lives, grows, and multiplies and is dependent on for its survival in nature

Can be environment or humans / animals (they can be both hosts and environments)

39
Q

What are the types of reservoirs?

A

Symptomatic cases (people with apparent signs of infection)

Carriers / asymptomatic cases

Zoonoses (animal carriers, often with complex life cycles, multiple hosts, and insect vectors)

Environment (food, water, soil, air, and other inert substances)

40
Q

How many diseases are zoonotic according to the CDC?

A

around 60% of all diseases

41
Q

What are portals of infection entry / exit in the human body?

A

respiratory tract
conjunctiva (eyes)
uro-genital tract
gastrointestinal tract
skin
placenta

most agents have a preferred portal; blocking that portal can prevent infection

42
Q

What are modes of transmission?

A

Any mechanism by which an infectious agent is propagated (spread) - bridging the gap between portals; Person to person contact

Indirect transmission (pathogens or agents are transferred onto an intermediate source - vehicle-borne (objects), airborne, vector-born (animals)

43
Q

What are examples of types of transmitted diseases?

A

Direct contact: ebola, impetigo, warts

Fecal - oral: Cholera, rotavirus, salmonella

Sexual: HPV, herpes, syphilis, chlamydia

Indirect - vector borne (Malaria, West Nile, Lyme)
Vehicle Borne (cryptosporidiosis), Campylobacteriosis
Airborne (anthrax, measles, influenza)

44
Q

What is susceptibility defined?

A

at risk of contracting a disease

45
Q

What is immunity defined?

A

the factors that alter the likelihood of infection and disease in the host when the agent is encountered

-innate / nonspecific immunity (present at birth, body’s first line of defense)
-acquired immunity (learned, body recognizes non-self antigens and develops memory to fight it)

46
Q

What are the types of acquired immunity?

A

Active - from artificial or natural exposure (vaccines)

Passive - from maternal sources, therapeutic doses or immune serums and antitoxins

47
Q

What is immunogenicity?

A

a person’s ability to produce an immune response after vaccination or infection

48
Q

What is herd immunity?

A

the proportion of individuals in the population who are resistant to a particular disease

(Once a high percentage is achieved, disease cannot spread)

49
Q

What is R0 (R naught?)

A

the expected number of secondary cases produced by a single (typical) infection in a completely susceptible population

If <1, outbreak will die out
If >1, epidemic will grow

50
Q

What are the links in the chain of infection?

A

pathogen / infectious agent > reservoir > mode of transmission > host

51
Q

What is the herd immunity threshold?

A

The average number of additional cases that occur from a single case in a susceptible population with no interventions (e.g. no vaccinations)

52
Q

Describe the ecosocial framework:

A
53
Q

What is a case, defined?

A

A person who has been diagnosed as having a disease, disorder, injury, or condition

54
Q

What is the primary case?

A

first disease case in a population

55
Q

What is the index case?

A

first case brought to the attention of the epidemiologist
(is not always primary)

56
Q

What are secondary cases?

A

persons who become infected / ill after a disease has been introduced to a population via contact with the primary case

57
Q

What are suspected and confirmed cases?

A

Suspected: person who has all signs and symptoms of a disease yet is not diagnosed

Confirmed: person confirmed with diagnosis as more info becomes available to physician (e.g. updated diagnosis info / disease definition, lab results)

58
Q

What is the triangle of modern epidemiology?

A

behavior, lifestyle, and chronic disease issues

59
Q

What is etiology?

A

the cause, set of causes, or manner of causation of a disease or condition.

typically both environmental and genetic, but sometimes only 1 is needed

Need motivation to change prior to fear and pain

60
Q

Describe the chronic disease epidemiological triangle

A
61
Q

What is the natural history of disease?

A

this refers to the progression of a disease in an individual over time

62
Q

Describe the natural history of disease schematic

A
63
Q

What are types of non-clinical (in-apparent) disease?

A

Preclinical disease (not yet clinical but destined to become so)

Subclinical disease (not clinically apparent and not destined to become so; usually determined via antibodies or cultures)

Persistent / Chronic Disease (inability to rid infection; may persist or disappear / reappear continually)

Latent disease (infection with no active multiplication of the agent)

64
Q

What are the three tiers of prevention?

A

Primary: avert disease before it develops (e.g. vaccinating children)

Secondary: early detection of disease in attempts to prevent or cure it (e.g. annual mammograms)

Tertiary: stop or limit spread of disease already present (prevent disability)

65
Q

What is endemic?

A

Habitual presence of a disease within a given demographic area

66
Q

What is epidemic?

A

Occurrence in a community or region of a group of illnesses of similar nature, clearly in excess of normal expectancy and derived from a common or propagated source

67
Q

What is pandemic?

A

worldwide epidemic

68
Q

What are the main reasons epidemics occur?

A

Susceptible people travel to an endemic area

They engage in new / unusual social, behavioral, or cultural practices

Host susceptibility and response typically adjusted by immuno-suppression or malnutrition or other diseases

69
Q

Why do epidemics end?

A

no more susceptible individuals / susceptibility decreases
no more exposure to the source / contamination
pathogen becomes less able to produce disease (less pathogenic)

70
Q

What are common epidemic interventions?

A

Control the source of the pathogen (remove source or exposure opportunities, sterilize pathogen, treat or quarantine)

Control or modify host response to exposure (modify behavior, use barriers)

Interrupt the transmission (vector control, personal hygiene)

71
Q

What are types of disease outbreaks?

A

Common vehicle exposure:
single exposure (point source, unlikely to create secondary cases)
multiple exposure (continuing common source)

Propagated (person to person transmission)

72
Q

How do we achieve herd immunity?

A

once the probability of an infected person encountering every other person in the population is the same (random mixing)

73
Q

What are qualifications of herd immunity?

A
  1. Disease restricted to a single host species
  2. Relatively direct transmission from one host to another
  3. Infections must induct solid immunity
  4. Outbreaks only occur in randomly mixing populations
74
Q

What is an incubation period (defined)?

A

Interval from receipt of infection to the time of onset of clinical illness

75
Q

What is an epidemic curve?

A

Plot of the number of cases against the time of onset of a disease

(In a single exposure, this will show distribution of incubation periods)

76
Q

What are some reasons for epidemiologic transition?

A

Medical technology
Improved standard of living
Birth control
Improved nutrition
Sanitation and vector control
Improvements in lifestyle

77
Q

According to the CDC, what are the top 10 public health achievements?

A
  1. Vaccination
  2. Motor vehicle safety
  3. Safer workplaces
  4. Control of infectious diseases
  5. Decline in deaths from heart disease / stroke
  6. Safer and healthier foods
  7. Healthier moms and babies
  8. Family planning
  9. Fluoridation of drinking water
  10. recognition of tobacco as a health hazard
78
Q

Describe disease prevention efforts

A
79
Q

Describe the Iceberg of infectious disease

A

Epidemiology For Public Health (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions