Table 1.

Characteristics of US counties, 2000-2010

Characteristic	2000		2010		Change, 2000-2010
	Mean	SD	Mean	SD
Proportion of county population
Age 65 and older	0.147	0.042	0.159	0.042	0.012
Black	0.088	0.145	0.090	0.146	0.002
At or below federal poverty level	0.142	0.066	0.168	0.062	0.026
Adults without high school diploma	0.226	0.088	0.169	0.074	−0.057
In rural areas	0.599	0.310	0.586	0.315	−0.013
Uninsured	0.148	0.050	0.184	0.058	0.036
Medicare managed care penetration	0.050	0.094	0.160	0.118	0.110
Population density (residents per square mile)	243	1,667	259	1,725	16
Primary care physicians per 100,000	19.8	20.4	14.6	19.8	−5.2
Radiologists per 100,000	4.6	7.9	6.6	14.1	2.0
Hospital beds per 100,000	340	433	307	425	−33

N=3,141 counties

SD: standard deviation