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. 2013 Jun 25;3(6):e002843. doi: 10.1136/bmjopen-2013-002843

Table 1.

Baseline characteristics of patients >18 years undergoing major cancer surgery, Nationwide Inpatient Sample, 1999–2009

Variables Baseline characteristics
Overall (%) Without PSI event (%) With PSI event (%) p Value
Weighted number of patients 2 508 917 2 184 065 (87.1) 324 852 (12.9)
Age (years)
 Mean (SD) 65.9 (11.7) 65.4 (11.6) 69.5 (11.7) <0.001†
 Median (IQR) 66 (5874) 65 (5773) 71 (6278)
Gender
 Male 1 511 361 (60.3) 1 331 716 (61.1) 179 645 (55.3) <0.001*
 Female 993 704 (39.7) 848 527 (38.9) 145 177 (44.7)
Race
 Caucasian 1 525 021 (60.8) 1 324 373 (60.6) 200 648 (61.8) <0.001*
 Black 177 986 (7.1) 154 028 (7.1) 23 958 (7.4)
 Hispanic 98 532 (3.9) 86 128 (3.9) 12 404 (3.8)
 Other 93 041 (3.7) 81 492 (3.6) 11 549 (3.6)
 Unknown 614 337 (24.5) 76 293 (23.5) 76 293 (23.5)
CCI
 0 1 566 723 (62.4) 1 412 545 (64.7) 154 178 (47.5) <0.001*
 1 623 985 (24.9) 516 640 (23.7) 107 345 (33.0)
 2 127 538 (5.1) 102 276 (4.7) 25 262 (7.8)
 ≥3 190 670 (7.6) 152 603 (7.0) 38 067 (11.7)
Insurance status
 Private 1 057 919 (42.2) 968 015 (44.3) 89 904 (27.7) <0.001*
 Medicaid 80 666 (3.2) 66 947 (3.1) 13 719 (4.2)
 Medicare 1 265 920 (50.5) 1 056 618 (48.4) 209 302 (64.4)
 Other 104 412 (4.2) 92 485 (4.2) 11 927 (3.7)
Median household income by ZIP code
 1–24 999 369 796 (14.7) 313 652 (14.4) 56 144 (17.3) <0.001*
 25 000–34 999 596 202 (23.8) 513 758 (23.5) 82 444 (25.4)
 35 000–44 999 646 869 (25.8) 563 398 (25.8) 83 471 (25.7)
 45 000+ 842 375 (33.6) 746 499 (34.2) 95 876 (29.5)
 Unknown 53 672 (2.1) 46 757 (2.1) 6915 (2.1)
Annual hospital volume
 1st quartile 591 675 (23.6) 510 024 (23.4) 81 651 (25.1) <0.001*
 2nd quartile 640 229 (25.5) 551 980 (25.3) 88 249 (27.2)
 3rd quartile 636 482 (25.4) 554 325 (25.4) 82 157 (25.3)
 4th quartile 640 531 (25.5) 567 737 (26.0) 72 794 (22.4)
Hospital location
 Rural 268 349 (10.7) 235 606 (10.8) 32 743 (10.1) <0.001*
 Urban 2 239 651 (89.3) 1 947 705 (89.2) 291 946 (89.9)
Hospital region
 Northeast 526 593 (21.) 458 684 (21.0) 67 909 (20.9) <0.001*
 Midwest 608 988 (24.3) 532 951 (24.4) 76 037 (23.4)
 South 8 822 566 (35.2) 762 212 (34.9) 120 354 (37.0)
 West 490 770 (19.6) 430 218 (19.7) 60 552 (18.6)
Hospital teaching status
 Non-teaching 1 135 065 (45.3) 979 636 (44.9) 155 429 (47.9) <0.001*
 Teaching 1 372 935 (54.7) 1 203 675 (55.1) 169 260 (52.1)

*A chi-square test was performed.

†A Mann-Whitney test was performed.

CCI, Charlson Comorbidity index; PSI, Patient Safety Indicator.