Question

- An epidemiologic survey of roller-skating accidents in Juneau, Alaska, a city with a population of 100,000, produced the following:

Number of skaters in Juneau during any given month = 12,000

Roller-skating accidents in Juneau = 600

Total number of residents injured from roller-skating = 1,800

Total number of deaths from roller-skating = 90

Total number of deaths from all causes = 900

- calculate crude death rate: ((# of deaths in a given year/ Reference population (during midpoint of the year))x 100,000)

- The cause-specific mortality rate from roller-skating: ((Mortality (or frequency of a given disease)/population size at midpoint of time period) x 100,000)

- The proportionate mortality (%) due to roller-skating was: ((mortality due to a specific cause during a time period/mortality due all causes during the same time period )x100)

- The case fatality rate of roller-skating accidents was: ((# of deaths due to disease/# of cases of disease) x100)

           

Answer 1

crude death rate: it is the number of deaths occurung among the population of a given geografical area during given year per 1000 mid year total population of the given geografical area during same year Multiplied by 100000.

- in given above question :

• How to calculate crude death rate : 900/100000x 100000 = 900

- crude death rate is 900.

*CAUSE SPECIFIC MORTALITY RATE :

Cause specific mortality rate is the number of deaths from specified cause per 100000 person - year at risk .

- the mortality rate from the specified cause for population .the numerator is the is the number of deaths attributed to specific cause during a specified time interval ,the denominator is the size of the population at the mid point of time interval.

- number of deaths from roller skating is 90,,.

- 90/10000 X 100000=90

- the cause specific death rate is 90.

*PROPORTIONATE MORTALITY RATE:

-it is a number of deths in a population due to specific disease or cause divided by the total number of deaths in the population during the time period such as year.

- total number of deaths in the year is 900.

- 90/900 x 100=10

- so ,the proportionate mortality rate is 10.

*CASE FATALITY RATE:

- it is the proportion dividing the number of deaths from a specified disease over a defined period of time by the numbercof dignosed with the disease during that time the resulting rtion is then multiplied by 100 to yield a percentage.

-

It is the proportionate deaths within the designed population of cases over the course of the disease dividing the number of death from a specified population.

- number of deaths due to skating is 90.

- total number of injured persons due to skating is 1800.

- 90/1800 x 100= 5.

So ,the case fatality rate is 5.