Question

The table below lists infant mortality in Maryland in 2007 and the estimated racial breakdown of the U.S. population according to the 2000 census. Calculations should be done by hand, but feel free to use software or Excel to check your work. The total U.S. population is 281,421,906.

race	Infant mortality (per 1000 births) - Maryland 2007	% of U.S. population (2000)
White	4.6	75.1
Black	14.0	12.3
Hispanic	3.8	12.5

1. (1) If possible, calculate the crude infant mortality rate for Maryland (all races).
2. (2) Calculate the race-adjusted infant mortality rate for 2007 Maryland using the U.S. population in 2000 as the standardizing population.
3. (1) The U.S. population is 281,421,906. Is that needed to solve this problem?

Answer 1

Solution (a):

Crude or average infant mortality rate (of all races) of Maryland in 2007 can be calculated if following data are available:

(1) Infant mortality rate for each race in 2007.

(2) Total Population of Maryland in 2007.

(3) % population of each race in Maryland in 2007.

Out of all three requirements, only (1) is available. (2) and (3) are missing in the question. Hence, we CANNOT calculate the crude infant mortality rate (of all races) of Maryland in 2007.

Solution (b):

The race-adjusted infant mortality rate for 2007 Maryland using the U.S. population in 2000 as the standardizing population can be calculated using following formula:

Weighted Rate (per 1000) =[(White IMR*White Population)+(Black IMR*Black Population)+(Hispanic IMR*Hispanic Population)] /Total US Population ..........(1)

where IMR --> Infant Mortality rate

The calculations using (1) have been summarized in Table I below for easier understanding.

Total US Population = 281421906

Table I: Solutions.

Race	IMR (per 1000)	% of US Population	Race population
A	B	C	D=(C/100)*Total US Population
White	4.6	75.1	211347851.406
Black	14	12.3	34614894.438
Hispanic	3.8	12.5	35177738.25

ANSWER = Weighted Rate (per 1000) = 5.6516 per 1000 (calculated using (1)).

Solution (c):

As can be seen from Solution (b) above, Total US Population IS REQUIRED for these calculations.