Trends in Ambulatory Prescribing of Antiplatelet Therapy among US Ischemic Stroke Patients: 2000–2007

Table 1

Ischemic stroke patient characteristics and antiplatelet agents prescribed: NAMCS, NAMCS 2000–2007^a,b.

Characteristic	Survey Year
	2000-01		2002-03		2004-05		2006-07
	(𝑁=285)		(𝑁=330)		(𝑁=352)		(𝑁=304)
	Population estimate	%	Population estimate	%	Population estimate	%	Population estimate	%
Total ischemic stroke visits	2,221,277	100%	2,238,540	100%	2,917,650	100%	2,150,851	100%
Race
White	1,605,408	72.3%	1,760,410	78.6%	2,266,603	77.7%	1,716,210	79.8%
Black	448,739	20.2%	184,064	8.2%	551,036	18.9%	392,536	18.3%
Other	167,130	7.5%	294,066	13.1%	100,011	3.4%	42,105	2.0%
Region
Northeast	340,302	15.3%	509,922	22.8%	393,472	13.5%	339,938	15.8%
Midwest	491,280	22.1%	366,347	16.4%	1,058,706	36.3%	536,408	24.9%
South	703,364	31.7%	579,150	25.9%	1,119,719	38.4%	928,226	43.2%
West	686,331	30.9%	783,121	35.0%	345,753	11.9%	346,279	16.1%
Age
18–44 years	46,907	2.1%	141,937	6.3%	137,665	4.7%	116,652	5.4%
45–64 years	549,189	24.7%	536,338	24.0%	885,617	30.4%	673,635	31.3%
≥65 years	1,625,181	73.2%	1,560,265	69.7%	1,894,368	64.9%	1,360,564	63.3%
Gender
Female	1,177,727	53.0%	1,196,813	53.5%	1,572,905	53.9%	834,076	38.8%
Male	1,043,550	47.0%	1,041,727	46.5%	1,344,745	46.1%	1,316,775	61.2%
Insurance^c
Private insurance	523,035	23.5%	553,314	24.7%	860,712	29.5%	633,122	29.4%
Medicare	1,488,002	67.0%	1,364,738	61.0%	1,538,343	52.7%	1,224,087	56.9%
Medicaid	76,721	3.5%	61,621	2.8%	106,824	3.7%	128,987	6.0%
Other	90,939	4.1%	206,476	9.2%	145,752	5.0%	75,490	3.5%
Location
MSA^d	1,580,138	71.1%	2,003,578	89.5%	2,546,768	87.3%	1,986,970	92.4%
Non-MSA	641,139	28.9%	234,962	10.5%	370,882	12.7%	163,881	7.6%
Antiplatelet prescribing
Overall antiplatelet agents	623,998	28.1%	641,900	28.7%	1,101,786	37.8%	1,010,462	47.0%
Aspirin only	360,067	16.2%	244,855	10.9%	213,034	7.3%	377,002	17.5%
Clopidogrel only	107,873	4.9%	151,764	6.8%	327,148	11.2%	231,652	10.8%
Aspirin and clopidogrel	23,542	1.1%	192,779	8.6%	456,787	15.7%	305,702	14.2%
Aspirin and dipyridamole	118,183	5.3%	47,861	2.1%	104,817	3.6%	96,106	4.5%
Dipyridamole only	3,148	0.1%	0	0.0%	0	0.0%	0	0.0%
Ticlopidine only	11,185	0.5%	4,641	0.2%	0	0.0%	0	0.0%
Setting
Physician office	1,502,370	67.6%	1,550,687	69.3%	2,231,054	76.5%	1,493,699	69.4%
Hospital OPD	65,065	2.9%	102,196	4.6%	62,847	2.2%	92,825	4.3%
Hospital ED	653,842	29.4%	585,657	26.2%	623,749	21.4%	564,327	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 10.0.1 (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.