An alternative method for selecting a standard population for direct adjustment is to use a “combined” population.
a. Complete Tables 5.23 and 5.24 using the population distributions from Study Question 1.
b. What is the ratio of the age-adjusted outpatient department visit rate in the population served by Hancock Regional Hospital Network to the age-adjusted outpatient department visit rate in the population served by Harrison Hospital System?
c. Describe the difference between the ratios of crude and age-adjusted outpatient department visit rates.
d. Do the ratios in part (c) differ from the adjusted rates calculated using the 2000 U.S. population as the standard? What is the significance of any differences?
Study Question 1
Tables 5.16 and 5.17 contain information on outpatient department visits in the populations served by two large regional hospital networks, Hancock Regional Hospital Network and Harrison Hospital System.
a. Compare the crude and age-adjusted rates of visits to the outpatient department in the populations served by Hancock Regional Hospital Network and Harrison Hospital System by completing the tables.
b. Compare the age-specific rates of visits to the outpatient department in the populations served by Hancock Regional Hospital Network and Harrison Hospital System.
c. Determine the ratio of the crude rates of the populations served by Hancock Regional Hospital Network and Harrison Hospital System.
d. The data presented in Tables 5.18 and 5.19 indicate that the population distributions among the populations served by Hancock Regional Hospital Network and Harrison Hospital System are different. Calculate the percentage of the population in each age group in both populations.
e. Before single summary rates between the populations served by Hancock Regional Hospital Network and Harrison Hospital System can be compared, outpatient department visit rates must be adjusted to account for differences in age distribution. Using the data in Table 5.20, perform a direct adjustment of crude outpatient department visit rates.
The first step is to select a standard population and its outpatient department visit rates. The standard population selected is the 2000 U.S. population (see Table 5.20). The next step is to calculate the expected number of outpatient department visits in each age group. This is accomplished by multiplying the number of persons in each age category in the standard population by the rates of outpatient department visits in each age group in the study populations (the populations served by Hancock Regional Hospital Network and Harrison Hospital System). Using Tables 5.21 and 5.22, calculate the age-adjusted outpatient department visit rates for the populations served by Hancock Regional Hospital Network and Harrison Hospital System by dividing the sum of the expected outpatient department visits by the total standard population.
f. What is the ratio of the age-adjusted outpatient department visit rate in the population served by Hancock Regional Hospital Network to the age-adjusted outpatient department visit rate in the population served by Harrison Hospital System?
g. Describe the difference between the ratios of crude and age-adjusted outpatient department visit rates.
