Morbidity and Mortality

Question 1

Commonly Used Measures of Morbidity

Answer 1

incidence
incidence density
attack rates
prevalence

Question 2

R0 (r-naught)

Answer 2

BASIC Reproduction Number (or reproductive rate), inherent of the agent and determines how a disease can spread through a population (important for herd immunity)
new cases over initial cases

Question 3

Relationship between R0 and the infectiousness of an agent

Answer 3

larger R0 = more infectious agent

Question 4

R

Answer 4

EFFECTIVE reproduction number, or the average number of cases generated by a single case in both susceptible and non-susceptible populations

Question 5

R>1

Answer 5

sustained trasnmission

Question 6

R<1

Answer 6

infection will die out

Question 7

Do disease control interventions affect R or R0?

Answer 7

R (remember R0 is inherent to the agent)

Question 8

Which is most common in epi - ratio, proportion, or rate?

Answer 8

Rate (relative frequency) - because it is based on counts (discrete data) and can be used in diagnostics and interventions

Question 9

4 Components Rate

Answer 9

1. Frequency (numerator)
2. Population at Risk (denominator)
3. Time period (ETC and ITC)
4. Location

Question 10

ETC (External Time Component)

Answer 10

length of time study was carried out

Question 11

ITC (Internal Time Component)

Answer 11

per unit of time to which a specific rate applies

Question 12

Incidence Rate

Answer 12

measure of rate

Question 13

Incidence Density

Answer 13

used when the entire population at risk is not observed through the entire defined period (ex: 5.7 cases per 100 calf months)

Question 14

Primary Attack Rate

Answer 14

number of those ill/
number in exposure group being assessed

Question 15

Secondary Attack Rate

Answer 15

true population at risk = total pop. minus the primary cases

Question 16

Which is a measure of pathogen infectivity - primary or secondary attack rate?

Answer 16

Secondary Attack rate

Question 17

Main assumption of secondary attack rate?

Answer 17

all secondary cases caught the disease from the primary cases

Question 18

Prevalence

Answer 18

proportion

Question 19

What type of study is used to determine prevalence of disease?

Answer 19

cross-sectional (and case control)

Question 20

Label the bathtub.
incidence, prevalence, recurrence, mortality

Answer 20

Question 21

What types of studies use incidence?

Answer 21

clinical trials and cohort

Question 22

Mortality Rate

Answer 22

number of deaths/population at risk (can be overall or specific)

Question 23

Case Fatality Rate

Answer 23

Question 24

What is case fatality rate a measure of?

Answer 24

virulence

Question 25

Measure of Association with Cross Sectional and Case Control Studies (Prevalence) (Retrospective)?

Answer 25

Odds Ratio

Question 26

Measure of Association with Cohort and Clinical Trial Studies (Incidence) (Prospective)?

Answer 26

Relative Risk

Question 27

Relationship Between Prevalence and Incidence in Rapidly Fatal Cases?

Answer 27

incidence will be higher than prevalence

Question 28

Mathematical Equation describing the relationship between Incidence, Prevalence, and Duration of Disease?

Answer 28

Question 29

Is prevalence more relevant in acute or chronic?

Answer 29

chronic (in acute, will be fairly equal to incidence)