Different measures of disease are useful to evaluate and assess public health programs and needs in different situations. For each of the following questions, state which measure would best support your goal. Measures of disease:

I = incidence rate (p. 126)
P = prevalence (p. 113)
L = lifetime prevalence (p. 114)
M = crude mortality rate (crude death rate) (p. 112)
R = sex ratio (counts) (p. 109)

a. To demonstrate the risks of car-train crashes at railroad crossings without warning signals.
b. To demonstrate the amount of children's exposure to secondhand cigarette smoke.
c. To estimate the number of persons who have had leukemia during their lifetimes.
d. To estimate the number of healthcare facilities needed to support patients with Alzheimer's disease.
e. To argue that mortality from HIV infection is a more serious public health problem in one region of the US than another.

Different Measures of Disease

Question              Measure of Disease

a.                           I = incidence rate

b.                           P = prevalence

c.                           L = lifetime prevalence

d.                           L = lifetime prevalence

e.                           M = crude mortality rate

Explanation:

a) Measures of disease:

I = incidence rate (p. 126): measures the frequency of disease occurrence in a population over time. It is measured as new episodes of illness in a period divided by the population.

P = prevalence (p. 113): ratio or proportion of persons in a population with a disease at a time or over time.  It is based on a sample.

L = lifetime prevalence (p. 114):  the proportion or ratio of a population who had a disease at some point in their life.

M = crude mortality rate (crude death rate) (p. 112): the ratio of deaths in a period among a geographical population.

R = sex ratio (counts) (p. 109): ratio of male and female population.