Table 2. Patient and Hospital Characteristics of Both the Unmatched and Propensity‐Score–Matched Cohort of Patients
VariableUnmatched PatientsP ValuePropensity‐Score MatchedP Valuea
Early Invasive (%)Initial Conservative (%)Early Invasive (%)Initial Conservative (%)
Total number of patients164 740 (100)198 760 (100)21 681 (100)21 681 (100)
Primary diagnosis
NSTEMIb161 020 (98)185 055 (93)<0.000121 130 (98)20 247 (93)<0.0001
UAb3720 (2)13 705 (7)<0.0001550 (3)1434 (7)<0.0001
Patient demographics
Age, mean y (SD)65 (12)71 (13)<0.000167 (11)68 (13)0.09
Female sex64 130 (39)91 945 (46)<0.00019044 (42)9176 (42)0.20
Race<0.0001<0.0001a
White109 040 (70)128 515 (69)15 063 (70)14 983 (69)
Black20 000 (13)26 500 (14)2768 (13)3163 (15)
Hispanic16 295 (10)20 015 (11)2227 (10)2093 (10)
Asian or Pacific Islander4400 (3)5660 (3)606 (3)577 (3)
Other6110 (4)5655 (3)868 (4)710 (3)
Primary expected payer<0.00010.02a
Medicare95 625 (58)142 420 (72)14 157 (65)14 262 (66)
Medicaid12 845 (8)14 590 (7)1477 (7)1798 (8)
Private insurance39 630 (24)28 845 (14)4327 (20)3902 (18)
Uninsured10 160 (6)7390 (3)1037 (5)1075 (5)
Other5110 (3)4565 (2)581 (3)554 (3)
Weekend admission33 325 (20)59 330 (30)<0.00015279 (24)5379 (25)0.27
Household income (median)<0.0001<0.0001a
0 to 25th percentile53 420 (33)66 370 (34)7384 (34)7280 (34)
26 to 50th percentile43 660 (27)51 265 (26)5821 (27)5668 (26)
51 to 75th percentile36 995 (23)43 555 (23)4895 (23)4921 (23)
76 to 100th percentile27 175 (17)32 760 (17)3581 (17)3812 (18)
Patient characteristics
Smoking54 065 (33)44 355 (22)<0.00016067 (28)5901 (27)0.08
Dyslipidemia125 075 (76)131 195 (66)<0.000115 786 (73)15 666 (72)0.20
Obesity45 060 (27)43 055 (21)<0.00015449 (25)5369 (25)0.38
Known history of CAD146 755 (89)136 395 (69)<0.000118 399 (85)18 493 (85)0.21
Family history of CAD13 100 (8)7365 (4)<0.00011148 (5)1115 (5)0.48
Past MI20 705 (13)25 895 (13)<0.00012922 (14)3011 (14)0.21
Past PCI137 975 (84)172 170 (87)<0.00013519 (16)3548 (16)0.71
Past CABG12 640 (8)24 895 (13)<0.00012178 (10)2269 (11)0.15
Past stroke or TIA9150 (6)13 390 (7)<0.00011316 (6)1321 (6)0.92
Carotid artery disease4080 (3)4750 (2)0.09573 (3)575 (3)0.95
Peripheral vascular disease25 335 (15)36 090 (18)<0.00013819 (18)3817 (18)0.98
Pulmonary circulation disease145 (<1)275 (<1)<0.000121 (<1)29 (<1)0.26
Dementia3000 (2)15 350 (8)<0.0001562 (3)508 (2)0.10
Atrial fibrillation22 725 (14)39 970 (20)<0.00013536 (16)3578 (17)0.59
Alcohol abuse3525 (2)3830 (2)<0.0001454 (2)434 (2)0.50
Deficiency anemia32 325 (20)55 310 (28)<0.00015062 (23)5101 (24)0.66
Collagen vascular disease3505 (2)4410 (2)0.06480 (2)471 (2)0.79
Chronic blood loss anemia1295 (1)2085 (1)<0.0001197 (1)200 (1)0.88
Congestive heart failure690 (<1)2005 (1)<0.0001124 (<1)145 (<1)0.20
Valvular disease195 (<1)615 (<1)<0.000136 (<1)47 (<1)0.23
Chronic pulmonary disease35 540 (22)52 430 (26)<0.00015252 (24)5322 (25)0.43
Coagulopathy9480 (6)11 610 (6)0.271313 (6)1280 (6)0.50
Liver disease2895 (2)4385 (2)<0.0001420 (2)416 (2)0.89
Renal disease (chronic)41 815 (25)78 900 (40)<0.00016967 (32)7005 (32)0.70
Electrolytes abnormalities34 070 (21)56 890 (29)<0.00015170 (24)5203 (24)0.71
AIDS120 (<1)175 (<1)0.1216 (<1)14 (<1)0.72
Drug abuse3050 (2)3425 (2)<0.0001392 (2)394 (2)0.94
Depression14 495 (9)19 320 (10)<0.00011971 (9)2040 (9)0.25
Hypertension138 115 (84)162 920 (82)<0.000118 088 (83)18 086 (83)0.98
Hypothyroidism19 215 (12)29 180 (15)<0.00012801 (13)2819 (13)0.80
Lymphoma705 (<1)1240 (0.6)<0.0001110 (<1)114 (<1)0.79
Metastatic cancer625 (<1)2050 (1)<0.0001114 (<1)106 (<1)0.59
Solid tumor without metastasis1720 (1)3480 (2)<0.0001289 (1)295 (1)0.80
Other neurological disorder7385 (5)16 065 (8)<0.00011142 (5)1192 (6)0.29
Paralysis2735 (2)5445 (3)<0.0001431 (2)457 (2)0.38
Psychoses4040 (3)6860 (4)<0.0001622 (3)597 (3)0.47
Peptic ulcer (nonbleeding)35 (<1)35 (<1)0.434 (<1)2 (<1)0.41
Weight loss3330 (2)6725 (3)<0.0001542 (3)518 (2)0.46
Cardiogenic shock6100 (4)5220 (3)<0.0001678 (3)654 (3)0.50
Intracranial hemorrhage150 (<1)255 (<1)<0.000121 (<1)24 (<1)0.66
Acute ischemic stroke2315 (1)3185 (2)<0.0001328 (2)337 (2)0.73
Gastrointestinal bleeding2545 (2)5530 (3)<0.0001433 (2)455 (2)0.46
Invasive procedure
PCIb159 585 (97)59 810 (30)<0.000110 415 (48)3862 (18)<0.0001
CABGb25 650 (16)11 760 (6)<0.00013037 (14)1820 (8)<0.0001
Hospital characteristics
Hospital bed size<0.00010.05
Small13 150 (8)26 530 (13)2062 (10)2203 (10)
Medium40 040 (24)54 740 (28)5568 (26)5553 (26)
Large111 550 (68)117 490 (59)14 051 (65)13 925 (64)
Hospital location<0.00010.14
Urban teaching92 320 (56)91 430 (46)11 133 (51)11 532 (53)
Urban nonteaching61 130 (37)81 580 (41)8811 (41)8213 (38)
Rural11 290 (7)25 750 (13)1737 (8)1936 (9)
In‐hospital mortality3320 (2.0)9605 (4.8)<0.0001475 (2.2)826 (3.8)<0.0001
  • All percentages are approximated to the nearest integer. AIDS indicates acquired immune deficiency syndrome; CABG, coronary artery bypass graft surgery; CAD, coronary artery disease; NSTEMI, non‐ST‐elevation myocardial infarction; MI, myocardial infarction; PCI, percutaneous coronary intervention; TIA, transient ischemic attack; UA, unstable angina.

  • a Although P value is significant the difference in % between both arms was <5% and thus deemed clinically nonsignificant.

  • b Variables were not included in the propensity score matching.