Question

Regionville is a community of 100,00 persons. During 1985, there were 1000 deaths from all causes. All cases of tuberculosis have been found, and they total 300 (200 males and 100 females). During 1985, there were 60 deaths from TB, 50 of them in males. What is thei a) crude mortality rate for Regionville 6) The proportionate mortality due to TB c) The case fatality rate for TB d) The cause specific mortality rate for TB

Answer 1

The following information are given in the question for the year 1985:

Total estimated population = 100,000

Total no. of deaths = 1,000

Total no. of cases of tuberculosis = 300 (Males-200, Females-100)

Total no. of deaths due to tuberculosis = 60 (Males - 50, Females- 10).

We have to find the following:

a. Crude Mortality Rate:

The crude mortality rate gives the rate of death in a given population over a specific time period (such as a calendar year). It is usually represented by no. of deaths per 1000 or per 100,000 of the population.

The crude mortality rate is given by the formula = Total no. of deaths in a year/Total estimated population

Thus, here Crude Mortality Rate = 1000/100,000 = 1/1000.

So, in this population, crude mortality rate is 1 in 1000, or 1000 every 100,000.

b. Proportionate Mortality due to Tuberculosis:

The proportionate mortality due to a particular cause such as the disease tuberculosis gives the proportion of the deaths caused due to that particular reason. It is represented by no. of deaths attributed to that cause every 100 or 1000 deaths.

It is given by the formula = No. of deaths due to a particular cause/Total no. of deaths

So, in this case, proportionate mortality due to tuberculosis = No. of deaths due to Tuberculosis/Total no. of deaths

= 60/1000

= 6/100

Thus,for every 100 deaths, 6 is due to tuberculosis. Therefore, proportionate mortality rate of tuberculosis is 6 in 100 or 60 in 1000 for this population in 1985.

c. Case fatality rate for Tuberculosis:

Case fatality rate for a particular disease is the rate of no. of cases which resulted in death of the individual. It is given by no. of cases which resulted in death per 100 cases.

It is given by = Total no. of deaths due to a disease/No. of cases reported of that disease.

Therefore, case fatality rate for tuberculosis = 60/300

= 20/100 = 1/5

For males, case fatality rate of tuberculosis = 50/200

= 25/100 = 1/4

For females, case fatality rate of tuberculosis = 10/100

= 1/10

Thus, for the general population 1 in every 5, or 20 in every 100 cases of tuberculosis turned out to be fatal. The fatality rate was higher in males with 1 in every 4, or 25 in every 100 cases of tuberculosis being fatal, while it was lower in females, with 1 in 10, or only 10 in every 100 cases resulting in death.

d. Cause Specific Mortality rate for Tuberculosis:

Cause specific mortality rate is simply the rate of deaths in a population that can be attributed to one specific cause. It is usually represented by rate of death for every 100,000 individuals.

It is given by the formula = No. of deaths due to a particular cause/Total estimated population size

Hence, the cause-specific mortality rate for tuberculosis = No. of deaths due to tuberculosis/ Total population

   = 60/100,000 = 3/5000

Therefore, in this community, 60 out of every 100,000 or 3 out of 5000 individuals are at risk of death by tuberculosis.