Age and Gender Adjustment in Two Managed Care

Age and Gender Adjustment in Two Managed Care Organizations

The purpose of standardization is to make two or more populations “similar” along dimensions in which
they differ. Earlier, we demonstrated two methods of age-adjustment. For example, we know that
Florida has proportionately more older folks, and older folks die at higher rates than younger folks. In
order to compare the mortality rate of Florida to Alaska, we needed to control for this disparity by
adjusting for differences in the age mix of the two states. Conceptually, we can adjust for more than
one dimension, e.g., age and gender, if we want to compare two or more populations, know that the
age and gender mix will be different in those two populations, and also know that some disease-specific
mortality rates depend on both age and gender. Such is the case with cardiovascular disease in two
large MCOs, Bluegrass East (BGE) and Bluegrass West (BGW), the former with 100,000 members, and
the latter with 120,000 members. Suppose we want to compare the cardiovascular mortality rate of
BGE and BGW. Suppose that BGE has a higher proportion of older folks, and a higher proportion of
women, than BGW. Assume that the crude disease-specific mortality rate for cardiovascular disease is
290 (per 100,000) in BGE and 160 (per 100,000) in BGW.
QUESTIONS
1. From these statistics alone, which MCO has the higher cardiovascular mortality rate?
2. The member mix in BGE and BGW is quite different. In BGW, 90% of the population is less than
55 years old compared to 77% in BGE. Refer to Table 6.7 to guide the calculation of age-adjusted
cardiovascular mortality rates using the direct age- adjustment technique and the U.S. population
as the standard. With age-adjusted rates, which MCO has the higher mortality rate?
3. Now assume that 60% of the members in BGW are men compared to 40% in BGE. Men have
higher cardiovascular mortality rates than women. Refer to Table 6.8 to calculate age and gender
adjusted cardiovascular mortality rates. With age- and gender-adjusted rates, which MCO has the
higher cardiovascular mortality rate?

Table 6.7 Direct age adjustment of cardiovascular mortality for Bluegrass East (BGE) and
Bluegrass West (BGW) Managed Care Organizations
Age Age-specific
Mortality
rate
Per 100,000
BGW
Age-specific
Mortality
rate
Per 100,000
BGE
U.S. mix
(2000)
BGW
expected
BGE
expected
1-54 25 20 210,000,000
55+ 1300 1325 70,000,000
Total 280,000,000
Table 6.8. Direct age and gender adjusted cardiovascular mortality for Bluegrass East (BGE)
and Bluegrass West (BGW) Managed Care Organizations
Age Age
andgender
specific
Mortality
rate
Per 100,000
BGW
Age
andgender
specific
Mortality
rate
Per 100,000
BGE
US BGW
(expected)
BGE
(expected)
Males
1-54
55+
30
1425
30
1500
105,000,000
35,000,000
Females
1-54
55+
10
1175
15
1225
100,000,000
40,000,000
280,000,000

Age and Gender Adjustment in Two Managed Care Organizations