Mortality Rates - Quantify Number of Deaths in A Population

Maternal Mortality Rate

# deaths (of moms) assigned to pregnancy- related causes during a given time interval ---------------------------------------------- x 1000 # live births during the same time interval

Death-to-Case Ratio

# deaths assigned to a specific disease during a given time interval ---------------------------------------- x 1000 # new cases of that disease reported during the same time interval

Proportionate Mortality

# deaths assigned to a specific cause during a given time interval ---------------------------------------- x 1000 total # deaths from all causes during the same interval

Cause-specific Death Rate (Also known as cause-specific mortality rate)

# deaths assigned to a specific cause during a time interval ----------------------------------------- x 1000 Estimated mid-interval population

Infant Mortality Rate

# deaths of infants (under 1 year of age) during a given time interval --------------------------------------------- x 1000 # live births during the same time interval

Neonatal Mortality Rate

# deaths of neonates (under age 28 days) during a given time interval -------------------------------------- x 1000 # live births during the same time interval

Postneonatal Mortality Rate

# deaths of postneonates (aged 28 days to <1 year) during a given time interval ---------------------------------------------- x 1000 # live births during the same time interval

Age-specific Death Rate (Also known as Age-specific mortality rate)

# of deaths within a specific age group during time interval ------------------------------------------ x 1000 Estimated mid-interval population at that same age group

Case fatality rate (is actually a proportion)

# of people dying during a specified period of time after disease onset or diagnosis ------------------------------------------ x 100 # of people with the specified disease

Years of Potential Life Lost (YPLL)

= Expected age of death (standard in country) - Actual age of death Can be added for all persons dying from a particular type of illness.

Why measure YPLL?

Deaths at an early age result in a greater loss of productivity than deaths at an old age. Scientists would want to report this number to understand the burden of early life lost.

How do you interpret case fatality? What does it measure?

It measures the percentage of people who have a certain disease that die within a certain time after their disease was diagnosed. It is a measure of the severity of a disease.

How are multiple births (e.g. twin births) considered when calculating maternal mortality rate?

Multiple births would be counted as one birth. If not, this would skew maternal mortality rate to be lower than it really is.

If a woman dies from an abortion procedure, is it considered a pregnancy-related death when calculating maternal mortality rate?

No, because abortion is not considered a live birth.

Mortality Rate

Number of Deaths ----------------------------------- x 1000 Population at risk x time interval

Difference between Proportionate Mortality and Mortality Rate

Proportionate mortality has the total number of deaths from all causes in denominator compared to Mortality rate that has population at risk in the denominator.

Crude Death Rate (Also known as crude annual mortality rate)

Total # deaths during time interval -------------------------------------- x 1000 Estimated mid-interval population