Q.1 A population of 750 healthy females was followed for the development of heart disease for 25 years. 75 of these female developed heart at 7 years, then another 50 developed it at 15 years, and 10 died from other causes at the end of observation period. Another 55 females were lost to follow up at 3 years. The remainder were followed for the entire period. Calculate the:
Prevalence of heart disease at the end of 7 years in this population
Cumulative incidence of heart disease in this population
Incidence density/incidence rate of heart disease in this population
Which measure (cumulative incidence or incidence density/incidence rate) will be most appropriate for interpreting findings? Why?
Q.2 Assume that there were 805 new cases of legionnaires disease was diagnosed among residents in Boston, MA and 800 new cases were diagnosed in Albuquerque, NM in 2016. Based on these data is it accurate to conclude that the incidence of legionnaire’s disease is higher in Boston than Albuquerque? Why or why not?
Population and Number of Deaths by Age for Communities X and Y
Community X
Community Y
Age (years)
Population
Deaths
Death Rate (per 1,000)
Population
Deaths
Death Rate (per 1,000)
Under 1
1,000
25
5,000
150
1-4
3,000
3
20,000
10
15-34
6,000
6
35,000
35
35-54
13,000
75
17,000
85
55-64
7,000
105
8,000
250
65 and older
20,000
1,600
15,000
1,350
All ages
50,000
1,814
100,000
1,880
Calculate and compare the overall crude death rates for Communities X and Y respectively.
Calculate and compare the age-specific death rates of Communities X and Y. What can you deduce from this? Are these comparisons different from the crude rates?
Standard Population by Age and Age-specific Mortality Rates for Communities N and Q
Age (years)
Standard Population for (N and Q)
Mortality Rate in N (per 1,000)
Expected Cases at N’s rates
Mortality Rate in Q (per 1,000)
Expected Cases at Q’s rates
Under 1
9,500
25.0
35.0
1-4
55,000
7.0
3.0
15-34
75,000
5.0
10.0
35-54
65,000
25.0
15.0
55-64
30,000
3.0
7.0
65 and older
35,000
75.0
80.0
All ages
269,500
42.5
21.3
Using the appropriate adjustment method, calculate the overall adjusted mortality rates for Communities N and Q respectively with the given standard population. Indicate which adjustment method was used.
Can you calculate the SMR for Communities N and Q from the information provided? Explain the reason for your answer.
