Mortality Flashcards
Crude mortality rate
TotalDeaths/TotalPopulation
x 100,000
Crude Rate is a summary rate. Describe single population. But not useful to compare between populations or the cause.
Age Specific Rate
NoDeaths among group during point in time/ NoPersons who are aged among group
x 100,000
Number of expected deaths
AgeSpecific rate * Standard Population
/100,000
Standard population
Population group A + Population Group B
Standarized population or use a comparable population such as US populat
Cause specific rate
Deaths due to specific Cause/
Population at midpoint of time period
Proportional Mortality Ratio (PMR)
Mortality due to a Specific Cause during time Period /
Mortality due to all causes during same time period
x 100
Proportion of deaths was due to a certain disease (e.g. HIV).
Indicates relative importance of a specific cause of death; not a measure of the risk of dying of a particular cause.
1588 deaths due to HIV in 2008
Total number of all cause deaths were 41,300 also in 2008,
PMR (%) for HIV among the 25- to 34-year-old group = (1,588/41,300)*100 = 3.8%
Adjusted rates
Adjusting for demographic factors removes differnces in composition between populations
Direct: Needs standard Population
When stratum specific rates are known (when knowing mortality rates specific for different age groups)
Indirect: When they are not known. But often to calculate SMR
Standarized Mortality Ratio (SMR)
Observed number of deaths of certain group / Expected number of deaths of certain group
Indirect adjusted rate
<1, it means fewer deaths were observed in the study population, indicating the mortality rate is lower than the standard population.
1, it means the observed and expected numbers are the same, indicating that observed mortality in the study population is not unusual, compared to the standard population.
> 1, it means more deaths were observed in the study population, indicating the mortality rate is greater than in the standard population.
