Measures of Disease Frequency (Exam 1 Cut Off)

Question 1

Morbidity

Answer 1

• Any departure from a state of physiological or psychological well-being
• Measured by prevalence and incidence

Question 2

Prevalence

Answer 2

Proportion or fraciton of a population that has a disease or condition at a certain point of time

Question 3

Incidence

Answer 3

• Number of new cases of a disease that develop in a population over a specified time period
• Disease occurence in persons who did not have the condition before
• Measure of risk
• Denominator: people at risk

Question 4

“People at Risk” does NOT include…

Answer 4

• People who already have disease

- People who cannot get a disease

Question 5

Incidence + Prevalence

Answer 5

• Prevalence depends on how many new cases occur and how long they remain cases
• Prevalence = Incidence * Duration
• Duration: time from occurrence to cure or death

Question 6

Choosing Between Incidence and Prevalence

Answer 6

Incidence

• For studies of cause of disease
• To estimate burden of diseases with short duration

Prevalence
-Estimate burden of diseases with long duration

Question 7

Mortality

Answer 7

• All cause mortality
• Age-specific mortality
• Mortality rates from selected causes

Question 8

Crude Mortality Rate

Answer 8

-Total number of deaths from all causes per 1,000 people in a population

Question 9

Cause-Specific Mortality Rate

Answer 9

-Total number of deaths from a specific cause

Question 10

Case-fatality Rate

Answer 10

-Number of deaths from a specific disease by the total number of cases of that disease (measure of severity)

Question 11

Infant Mortality Rate

Answer 11

-Number of deaths in children under 1 year of age occurring during a one year period per 1,000 livebirths

Question 12

Asociation

Answer 12

Statistical relationship between two or more variables

Question 13

Exporsure

Answer 13

Variable with potential causal characteristics

• Risk factors
• Preventive factors
• Certain treatments
• Demographic/behavioral characteristics

Question 14

Outcome

Answer 14

• Disease
• Side effects
• Complications
• Death
• Cure

Question 15

Goals of Clinical Studies

Answer 15

• Determine whether a certain risk/preventive factor (exposure) is associated with a particular outcome
• Achieved by comparing different measures of disease frequency by: calculating a ratio or a difference between two measures

Question 16

Relative Risk

Answer 16

Comparison of the incidence in one group versus another