Table 2.

Association between patient demographic and physician office/hospital characteristics and antiplatelet agent prescribed: NAMCS, NHAMCS 2000–2007^a , b.

	Antiplatelet medication
Characteristic	Aspirin only			Clopidogrel only			Aspirin and clopidogrel			Aspirin and dipyridamole
	(N = 233)			(N = 95)			(N = 63)			(N = 39)
	Population estimate	%	P value	Population estimate	%	P value	Population estimate	%	P value	Population estimate	%	P value
Total	1,194,958	—		818,437	—		978,810	—		366,967	—
Race
White	958,151	80.2%	0.40	581,489	71.0%	0.68	708,008	72.3%	0.91	341,339	93.0%	0.11
Black	201,745	16.9%		150,228	18.4%		203,509	20.8%		22,867	6.2%
Other	35,062	2.9%		86,720	10.6%		67,293	6.9%		2761	0.8%
Region
Northeast	304,874	25.5%	0.38	82,604	10.1%	0.52	111,832	11.4%	0.47	62,510	17.0%	0.75
Midwest	217,812	18.2%		287,327	35.1%		161,843	16.5%		108,731	29.6%
South	433,594	36.3%		259,449	31.7%		466,195	47.6%		84,482	23.0%
West	238,678	20.0%		189,057	23.1%		238,940	24.4%		111,244	30.3%
Age
18–44 years	65,453	5.5%	0.39	10,958	1.3%	0.03	17,561	1.8%	0.20	12364	3.4%	0.90
45–64 years	436,552	36.5%		116,735	14.3%		404,818	41.4%		95,313	26.0%
≥65 years	692,953	58.0%		690,744	84.4%		556,431	56.8%		259,290	70.7%
Gender
Female	632,517	52.9%	0.71	522,671	63.9%	0.15	192,540	19.7%	<0.01	113,778	31.0%	0.22
Male	562,441	47.1%		295,766	36.1%		786,270	80.3%		253,189	69.0%
Insurancec
Private insurance	355,686	29.8%	0.31	187,508	22.9%	0.47	405,119	41.4%	0.21	64,802	17.7%	0.73
Medicare	656,260	54.9%		572,429	69.9%		461,148	47.1%		267,898	73.0%
Medicaid	71,523	6.0%		26,884	3.3%		53,025	5.4%		10,678	2.9%
Other	55,345	4.6%		21,151	2.6%		14,927	1.5%		10,620	2.9%
Location
MSAd	994,903	83.3%	0.82	646,403	79.0%	0.58	852,053	87.0%	0.72	224,322	61.1%	0.30
Non-MSA	200,055	16.7%		172,034	21.0%		126,757	13.0%		142,645	38.9%
Setting
Physician office	711,071	59.5%	0.05	726,058	88.7%	<0.01	870,856	89.0%	0.01	317,518	86.5%	0.21
Hospital OPDe	56,218	4.7%		49,195	6.0%		5,305	0.5%		8,951	2.4%
Hospital ED	427,669	35.8%		43,184	5.3%		102,649	10.5%		40,498	11.0%
Year
2000-01	360,067	30.1%	0.13	107,873	13.2%	0.22	23,542	2.4%	<0.01	118,183	32.2%	0.62
2002-03	244,855	20.5%		151,764	18.5%		192,779	19.7%		47,861	13.0%
2004-05	213,034	17.8%		327,148	40.0%		456,787	46.7%		104,817	28.6%
2006-07	377,002	31.5%		231,652	28.3%		305,702	31.2%		96,106	26.2%

^aNAMCS: National Ambulatory Medical Care Survey, NHAMCS: National Hospital Ambulatory Medical Care Survey.

^bPopulation estimates were calculated using SAS-callable SUDAAN software, version 9.0.1 (Research Triangle Institute) to obtain proper variance estimations that accounted for the complex sampling design of the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey and results that were weighted to reflect national population estimates.

^cInsurance (payment source) does not sum to 100% because of missing data, ^dMSA: Metropolitan Statistical Area.

^eOPD: Outpatient Department.