Table 1.

Baseline characteristics of Medicare patients hospitalized for AMI

	1998-2001		2002-2004		2005-2007		2008-2010		All
N (AMI hospitalizations)	905168		720850		606779		557146		2789943
Age (years)
mean (standard deviation)	78.1 (7.7)		78.5 (7.9)		78.8 (8.2)		78.9 (8.4)		78.5 (8.0)
Age categories
65-74	348818	38.5%	264707	36.7%	217467	35.8%	204246	36.7%	1035238	37.1%
75-84	370825	41.0%	293094	40.7%	239354	39.4%	207128	37.2%	1110401	39.8%
85+	185525	20.5%	163049	22.6%	149958	24.7%	145772	26.2%	644304	23.1%
Race-sex categories
White male	410469	45.3%	322018	44.7%	273699	45.1%	251869	45.2%	1258055	45.1%
White female	399235	44.1%	315188	43.7%	262074	43.2%	236373	42.4%	1212870	43.5%
Black male	24896	2.8%	21110	2.9%	18104	3.0%	17801	3.2%	81911	2.9%
Black female	35969	4.0%	30374	4.2%	25616	4.2%	24779	4.4%	116738	4.2%
Other male	17083	1.9%	16133	2.2%	13803	2.3%	13542	2.4%	60561	2.2%
Other female	17516	1.9%	16027	2.2%	13483	2.2%	12782	2.3%	59808	2.1%
Comorbidites
Coronary atherosclerosis	594524	65.7%	494104	68.5%	413051	68.1%	379412	68.1%	1881091	67.4%
Congestive heart failure	382911	42.3%	306677	42.5%	257475	42.4%	223953	40.2%	1171016	42.0%
Specified arrhythmias	338240	37.4%	269608	37.4%	228947	37.7%	189864	34.1%	1026659	36.8%
Diabetes mellitus or diabetes complications	252095	27.9%	201733	28.0%	163671	27.0%	151199	27.1%	768698	27.6%
Chronic obstructive pulmonary disease	174064	19.2%	148773	20.6%	128604	21.2%	91244	16.4%	542685	19.5%
Valvular or rheumatic heart disease	142124	15.7%	121183	16.8%	110143	18.2%	64873	11.6%	438323	15.7%
Iron deficiency or other anemias and blood disease	141814	15.7%	117097	16.2%	96225	15.9%	92967	16.7%	448103	16.1%
Vascular or circulatory disease	130627	14.4%	109338	15.2%	93629	15.4%	87157	15.6%	420751	15.1%
Disorders of fluid, electrolyte, acid-base	98879	10.9%	89468	12.4%	105083	17.3%	105459	18.9%	398889	14.3%
Pneumonia	76623	8.5%	73940	10.3%	66324	10.9%	65370	11.7%	282257	10.1%
Angina pectoris, old myocardial infarction	77656	8.6%	56924	7.9%	44835	7.4%	37978	6.8%	217393	7.8%
Renal failure	72228	8.0%	85940	11.9%	134582	22.2%	155353	27.9%	448103	16.1%
Other urinary tract disorders	69486	7.7%	71355	9.9%	43033	7.1%	21731	3.9%	205605	7.4%
Dementia or other specified brain disorders	58345	6.4%	53769	7.5%	47066	7.8%	46669	8.4%	205849	7.4%
History of infection	38398	4.2%	26317	3.7%	20580	3.4%	20799	3.7%	106094	3.8%
Acute coronary syndrome	37310	4.1%	17290	2.4%	10620	1.8%	8097	1.5%	73317	2.6%
Cerebrovascular disease	36377	4.0%	25774	3.6%	19270	3.2%	17950	3.2%	99371	3.6%
Cancer	29259	3.2%	25229	3.5%	22720	3.7%	22131	4.0%	99339	3.6%
Hemiplegia, paraplegia, paralysis, functional disability	25710	2.8%	18444	2.6%	13525	2.2%	17036	3.1%	74715	2.7%
Stroke	19160	2.1%	14687	2.0%	12624	2.1%	10888	2.0%	57359	2.1%
Protein-calorie malnutrition	11475	1.3%	10832	1.5%	11500	1.9%	16002	2.9%	49809	1.8%
Asthma	11375	1.3%	10215	1.4%	9062	1.5%	8519	1.5%	39171	1.4%
Metastatic cancer or acute leukemia	7141	0.8%	6557	0.9%	6356	1.0%	6112	1.1%	26166	0.9%
End stage renal disease or dialysis	3983	0.4%	5222	0.7%	6850	1.1%	3525	0.6%	19580	0.7%
Decubitus ulcer or chronic skin ulcer	2457	0.3%	7094	1.0%	13454	2.2%	11903	2.1%	34908	1.3%

Abbreviations: AMI, acute myocardial infarction

P<0.001 across time for all characteristics, except hemiplegia, paraplegia, paralysis, functional disability (p=.45)