Table 1

Characteristics of patients before matching

VariableUnmatched analysisExact matched analysisP value
ValuesNot African–American
(n=519 618)
African–American (n=82 150)P valuesNot African–American
(n=56 161)
African–American
(n=56 161)
AgeMedian (Q1 to Q3)57 (37 to 74)37 (25 to 55)<0.00142 (27 to 59)42(27 to 59)1
SexFemale197 616 (38)20 014 (24.4)<0.00114 808 (26.4)14 808 (26.4)1
Male322 002 (62)62 136 (75.6)41 353 (73.6)41 353 (73.6)
Hypotension0503 073 (96.8)77 937 (94.9)<0.00155 546 (98.9)55 546 (98.9)1
116 545 (3.2)4213 (5.1)615 (1.1)615 (1.1)
ISSMedian (Q1 to Q3)12 (9 to 17)12 (9 to 18)<0.00110 (9 to 17)10 (9 to 17)1
GCS scoreMedian (Q1 to Q3)15 (15 to 15)15 (14 to 15)<0.00115 (15 to 15)15 (15 to 15)1
Injury typeBlunt495 856 (95.4)56 859 (69.2)<0.00146 300 (82.4)46 300 (82.4)1
Penetrating23 762 (4.6)25 291 (30.8)9861 (17.6)9861 (17.6)
InsuranceBlue Cross/Blue Shield23 915 (4.6)2181 (2.7)<0.0011433 (2.6)1433 (2.6)1
Medicaid49 081 (9.4)19 469 (23.7)11 558 (20.6)11 558 (20.6)
Medicare175 971 (33.9)13 101 (15.9)11 175 (19.9)11 175 (19.9)
No fault automobile25 867 (5)2937 (3.6)2086 (3.7)2086 (3.7)
Not billed (for any reason)1245 (0.2)492 (0.6)126 (0.2)126 (0.2)
Other15 181 (2.9)2721 (3.3)1420 (2.5)1420 (2.5)
Other government11 893 (2.3)2573 (3.1)1422 (2.5)1422 (2.5)
Private/commercial insurance152 989 (29.4)18 005 (21.9)14 039 (25)14 039 (25)
Self-pay54 497 (10.5)19 887 (24.2)12 353 (22)12 353 (22)
Workers’ compensation8979 (1.7)784 (1)549 (1)549 (1)
ACS trauma level<0.0011
I349 881 (67.3)64 041 (78)44 347 (79)44 347 (79)
II169 737 (32.7)18 109 (22)11 814 (21)11 814 (21)
  • Hypotension denotes a systolic blood pressure of <90 mm Hg.

  • ACS, American College of Surgeons; GCS, Glasgow Coma Scale; ISS, Injury Severity Score.