TABLE 1.

Comparison of Population-Weighted and -Unweighted Measures of Geographic Inequality in Life Expectancy at Birth in the United States, 1969–1973 and 1999–2003

		Life Expectancy at Birth		Measure of Health Inequality
Geographic Unit	Units	Min.	Max.	Unweighted Index of Disparity	Weighted Mean Log Deviation
1969–1973
Census region	4	70.2	72.2	1.67	0.050
Census division	9	69.7	72.4	1.80	0.072
State	51	65.9	74.3	4.36	0.137
Countya	3,087	56.2	85.0	16.77	0.423
1999–2003
Census region	4	76.2	78.5	1.61	0.074
Census division	9	74.7	78.7	2.02	0.097
State	51	73.0	80.7	4.43	0.150
Countyb	3,140	62.0	96.1	20.35	0.379
% Change, 1969–73 to 1993–2003
Census region				−3.6%	+48.0%
Census division				+12.2%	+34.7%
State				+1.6%	+9.5%
County				+21.2%	−10.4%

Notes: The Index of Disparity is calculated as the average deviation of each area's life expectancy from the area with the highest life expectancy, giving each area equal weight and expressed as a proportion of the life expectancy of the area with the highest life expectancy and multiplied by 100. The Mean Log Deviation weights each area by its population size and is calculated as the average difference between the logarithm of each area's life expectancy and the logarithm of the population average life expectancy (see the appendix for formulas).

^aOne county with a life expectancy at birth of 19.8 was excluded.

^bTwo counties with life expectancies at birth estimated as 4.0 and 102.0 were excluded.

Source: Authors’ calculations using SEER*Stat Software (National Cancer Institute Surveillance Research Program 2009), with underlying data provided by the National Center for Health Statistics 2009a, 2009b.