Descriptive Epidemiology & Measuring Disease Frequency

Question 1

The membership of this type of population is PERMANENT and defined by an event (ex: victims of 9/11, or women age 65+)

Answer 1

Fixed population

Question 2

The membership of this type of population is TRANSIENT and defined by being in or out of a particular “state” (ex: residents of the city of Honolulu or employed at Starbucks)

Answer 2

Dynamic population

Question 3

These statistics are useful for:

1. Understanding the health status of a population
2. Formulating hypothesis about etiology or the cause of disease, and
3. Planning, implementing, and evaluating public health programs to control and prevent adverse health events

Answer 3

Descriptive Epidemiological Statistics

Question 4

Name the first 4 W’s (out of 5 W’s) of Descriptive Epidemiology

Answer 4

1. What
2. When
3. Where
4. Who

Question 5

Measures of risk/disease frequency should take into account these 3 KEY ASPECTS:

Answer 5

1. Number of individuals affected w/the disease
2. Size of source population (total at risk for disease or exposed)
3. Length of time the population was followed

Question 6

A set of uniform criteria used to define a disease for public health surveillance. Enables public health to classify and count cases consistently across reporting jurisdictions, and should not be used by providers to determine how to meet a patient’s needs.

Answer 6

Case Definition

Question 7

This is the official CDC organization who develops national case definitions for National Notifiable Disease Surveillance System

Answer 7

Council of State Territorial Epidemiologists (CSTE)

Question 8

Type of case which involves a change in individual/group from well to ill (new case)

Answer 8

Incident Case(s)

Question 9

Type of case that includes all existing cases; current status of an individual or group whether ill or recovered (has or had disease)

Answer 9

Prevalent Case(s)

Question 10

Division of one number by another, numbers don’t have to be related (ex: 2:1)

Answer 10

Ratio

Question 11

Numerator is subset of denominator, often expressed as a percentage

Answer 11

Proportion

Question 12

Time is an intrinsic part of denominator. This term is most often misused.

Answer 12

Rate

Question 13

950 out of 1000 motorcycle victims are men
(950/1000)*100= 95%
This is an example of a ____

Answer 13

Proportion

Question 14

“200 per 100,000 population in 1 year”

This is an example of a ______

Answer 14

Rate

Question 15

The occurrence of NEW cases of disease in a population over a specified period of time

Answer 15

Incidence

Question 16

“Attack Rate (AR)=
(NEW cases/population at start of epidemic) * 100”

This is an example of ____

Answer 16

Incidence Proportion

Question 17

(# of new cases during time interval / population at risk during same time interval) * Constant (ex: 10,000, 100,000, etc)

This is the formula for:

Answer 17

Incidence Rate (IR)

Question 18

“Persons per year” is the layman’s term for ____

Answer 18

Person Years (PY)

Question 19

(Number of [new and old cases] at a specific point in time / Total population at risk) * Constant =

Answer 19

Prevalence Rate

Question 20

If incidence is low but duration of the disease is long, prevalence is relatively _____

Answer 20

high

Question 21

If incidence is high but duration is short, prevalence is relatively _____

Answer 21

low

Question 22

This type of map is used for clusters or outbreaks with a limited number of cases or geographical area.

Answer 22

Spot/Area Map

Question 23

Epi curves use a ______ instead of a line graph

Answer 23

histogram (column format)

Question 24

If during an outbreak, everyone is exposed over a brief period of time and everyone who becomes ill does so within one incubation period, then the outbreak is classified as a

Answer 24

point-source outbreak (ex: Snow’s cholera data)

Question 25

**In this type of outbreak, cases occur over more than one incubation period. The histogram shows multiple peaks.

Answer 25

Propagated Outbreak (ex: malaria)

Question 26

This type of outbreak which displays a histograph with a relatively flat curve is known as a

Answer 26

Common Source Outbreak (limited to no person to person transmission and the length of time of outbreak is long, often because it is from a source that is always present or is not recognized quickly enough for preventative measures to be put into place)(Ex: lyme disease- ticks are the vector, or a contaminated food source causing health issues until the food source is found)