Measuring Outcomes

Question 1

Define death rates

Answer 1

Number of deaths/number of people at risk of dying

Question 2

Define age-specific death rates

Answer 2

Death rate for specific group of population

Question 3

Define proportionate mortality

Answer 3

Number of deaths from a given cause, per 100 or per 1000 total deaths.

Question 4

Define infant mortality

Answer 4

Deaths of children aged 1-4 years. This is a basic health indicator.

Question 5

Which death rate is a basic health indicator?

Answer 5

Infant mortality

Question 6

Define maternal mortality rate

Answer 6

Risk of mothers dying from causes associated with delivering babies, complication of pregnancy or childbirth.

Question 7

Define adult mortality rate

Answer 7

Probability of dying between the ages of 15 and 60 years, per 1000.

Question 8

Define life expectancy

Answer 8

Average number of years an individual of given age is expected to live is current mortality rates continue

Question 9

Define age-standardised rates

Answer 9

Summary measures of death rate that a population would have if it had a standard age structure.

Question 10

Define morbidity

Answer 10

Any departure, subjective or objective, from a state of physiological or psychological well being.

Question 11

What is commonly used to measure morbidity?

Answer 11

Quality adjusted life years and disability adjusted life years.

Question 12

What are years of potential life lost (PYLL)?

Answer 12

Measure of health expectancy or number of potential years of life lost if they die before a certain age (normally before 65).

PYLL= (total number of deaths from a specific cause in each age group) x (average number of years of life lost as a result of each of these deaths).

Question 13

What are quality-adjusted life years (QALYs)

Answer 13

Weigh each year of life by the perceived quality of that life from a value of 1 (perfect) down to 0.

Question 14

What are disability-adjusted life years (DALYs)

Answer 14

Measure of overall disease burden, expressed as the cumulative number of years lost due to ill-health, disability or early death.

DALYs = Years of Life Lost (YLL) + Years Lost to Disability (YLD)

YYL- actual death
YLD- alive but reduced quality of life

Question 15

What is incidence?

Answer 15

The rate of occurrence of new cases in a given period in a given population.

Question 16

What are the two ways in which incidence is expressed as and calculated?

Answer 16

Rate = (number of new cases)/ person-time
Cumulative incidence (proportion) = (# of new cases during a time period)/ (#of disease-free subjects at the start of follow-up). Values range 0-1

Question 17

What is prevalence?

Answer 17

Frequency of existing cases in defined population at a give time.

Question 18

How is prevalence calculated?

Answer 18

(# cases of a disease present in a population)/ (# of persons in a population).

Question 19

If the incidence is low and the population is stationary, how else can prevalence be calculated?

Answer 19

(Incidence rate) x (average duration of disease)

Question 20

What is attack rate?

Answer 20

(Number of people affected) / (number of people exposed to each food)
Used for outbreaks that occur over a short period of time (e.g. salmonella outbreak).

Question 21

What is case fatality?

Answer 21

Deaths within those diagnose by the disease

Case fatality= (number of deaths from diagnosed cases in a given period) / (number of diagnosed cases of the disease in the same period) x 100.

Question 22

What is the relative risk, or risk ratio?

Answer 22

(Risk in the exposed population) / (risk in the unexposed population) = (Re/Ru)

Question 23

What is the attributable risk, risk difference?

Answer 23

(Risk difference): risk attributable to the exposure

Difference in risk between exposed and unexposed Re-Ru

Question 24

How do you calculate the percentage of cases that can be attributed to the exposure?

Answer 24

(Re-Ru)/Re x 100%