Intro To Epidemiology

Question 1

Why should you care about epidemiology ?

Answer 1

1. If you deal with animals in groups
2. The principles are essential for understanding: (spread of diseases; occurrence of complex diseases; impact of disease on the population)
3. To practice evidence-based veterinary medicine (most important reason)

Question 2

Why is practicing evidence-based veterinary medicine important ?

Answer 2

Helps you apply what you learn/read from external evidence to what you learned from your own clinical experience so that you can critically care for your patients.

A vet must be able to critically evaluate what they read, filter it and be reasonably skeptical with newly found research.

Epi is used to help evaluate the research and use it in your practice

Question 3

Name two sources of evidence:

Answer 3

1. Internal evidence (what you learned in clinics)

2. External evidence (what you learn from journals and research articles)

Question 4

What is epidemiology ?

Answer 4

It is “the study of the distribution and determinants of health-­‐related states or events in specified populations, and the application of this study to the control of health problems”

= the study of disease in populations

Question 5

What is the goal of veterinary epidemiology ?

Answer 5

Goal is to reduce the frequency of disease
occurrence, enhance productivity and improve animal welfare.

It deals with the investigation of diseases, productivity and welfare in animal populations

Question 6

What is the purpose of epi ?

Answer 6

1. Describes the distribution of health-related states/events (aka disease prognosis)
2. Identify determinants of health-related outcomes (aka cause and risk factors)

Question 7

Epi focuses on the individual animal

True or False ?

Answer 7

False

Focuses on the overall health of groups of animals

“The
use
of
these
methods
frequently
leads
the
practitioner
to
a
holistic,
population-­‐oriented
way
of
thinking
about
health
and
disease
that
is
quite
different
from
the
individual
patient-­‐
oriented
approach
of
clinical
medicine”

Question 8

You can have success with an epidemiological approach without knowing the etiological agent?

True or False

Answer 8

True

Question 9

How does the epidemiological approach focus on groups ?

Answer 9

1. Describes the individuals in a population with a diseases and those without a disease
2. Compares both groups
3. Identifies factors associated with the disease

Question 10

Who is the “father of modern epidemiology”?

Answer 10

John snow bc of his “shoe-leather technique” used to find out how ppl in London were getting sick from Cholera.

Question 11

Define risk ratio:

Answer 11

How much greater the risk of getting the disease is from one factor compared to another factor.

Ex:
The
number
of
deaths
per
house
supplied
was:
— Southwark
&
Vauxhall:
1,263/40,046
=
31
.5
per
1000
houses
— Lambeth:
98/26,107
=
3.8
per
1000
houses
— So
it
was
31.5/3.8
=
8
times
more
dangerous
to
drink
Southwark
and
Vauxhall
water
than
Lambeth
water

Question 12

Which epidemiology looks at the ratio of risks?

a. descriptive epidemiology
b. analytical epidemiology

Answer 12

b. analytical epidemiology

Question 13

Descriptive epidemiology:

Answer 13

The
study
of
the
amount
and
distribution
of
disease
in
a
specified
population
by
animal,
place
and
time
in
a
specified
population
(What,
Who,
When,
Where)

Disadvantage: Cannot infer causality

Question 14

Analytical epidemiology: (main branch of epidemiology)

Answer 14

Determine
if
there
is
an
association
between
an
exposure
and
outcome
in
a
population
and
how
strong
the
association
is
(Why)

Ultimate
goal
is
to
determine
if
an
exposure
factor
causes
the
disease

Question 15

What is an association ?

Answer 15

There is an association between an exposure and an outcome when they are dependent on one another
(Ex. when one changes so does the other)

Independent (not associated) When one quantity changes nothing happens to the other

*Just bc there is an association does not mean that the factor caused the disease.

Question 16

Define outcome:

Answer 16

A result or response, usually a disease or some other change in health status

Question 17

Define exposure:

Answer 17

Any potential determinant of disease or health status

Question 18

Define determinant:

Answer 18

An exposure that is shown to be associated with the outcome.

Also called risk factors (increased risk) or protective factors (decreased risk)

Question 19

Epidemiology does not determine the cause of a disease in a given individual

True or False

Answer 19

True

it
determines
the
relationship
or
association
between
a
given
exposure
and
the
frequency
of
disease
in
populations

Question 20

An
identifiable
relationship
between
an
exposure
and
an
outcome is called a(n)....

Answer 20

Association

Implies
that
the
exposure
might
cause
the
outcome

Question 21

Implies
that
there
is
a
true
mechanism
that
leads
from
the
exposure
to
the
disease

Answer 21

Causation

Question 22

What does the epidemiological triad consist of ?

Answer 22

an external agent, a susceptible host; an environment that brings the two together.

Inadequate for other diseases that appear to have multiple contributing causes without a single necessary one (use rothman’s model instead)

Question 23

A
component
that
appears
in
every
pie
for
a
particular
disease
is
called
a
\_\_\_\_\_\_\_\_\_
cause,
because
without
it,
the
disease
will
not
occur

Answer 23

necessary

Question 24

The bradford-hill criteria is used to determine whether an association is causal by specific criteria/view points

True or False

Answer 24

True