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Table 1 Unadjusted and adjusted baseline patients’ characteristics

From: Mid-term outcomes of off-pump versus on-pump coronary artery bypass graft surgery; statistical challenges in comparison

Baseline characteristics of patients before PS matching Baseline characteristics of patients after PS matching
  Total
(n = 8163)
Off-pump
(n = 1589)
On-pump
(n = 6574)
p value Off-pump
(m = 1312)
On-pump
(m = 1312)
p value
Female 25.7%
(2096)
26.4%
(420)
25.5%
(1676)
0.462 26.2%
(351)
25.8%
(346)
0.860
Age 62 ± 10 62 ± 10 62 ± 9 0.260 62.03 ± 9.88 62.00 ± 9.41 0.964
BMI
 < 30 75.1%
(6096)
74.3%
(1170)
75.3%
(4926)
0.423 74.9%
(331)
74.1
(992)
0.658
 ≥ 30 24.9%
(2016)
25.7%
(404)
24.7%
(1612)
  25,1%
(336)
25.9%
(347)
 
Hb 13.89 ± 1.74 13.76 ± 1.79 13.92 ± 1.72 0.002 13.92 ± 1.71 13.85 ± 1.76 0.57
Graft number* 3 [3, 4] 3 [2, 3] 3 [3, 4] < 0.001 3 [2, 3] 3 [2, 3] 0.942
Creatinine* 0.90 [0.77,1.07] 0.90 [0.77,1.08] 0.97 [0.77,1.06] 0.108 0.90 [0.77, 1.07] 0.90 [0.77, 1.09] 0.739
eGFR 86.38 [67.22, 107.74] 85.5 [65.68, 107.89] 86.44 [67.78, 107.64] 0.159 85.28 [65.71, 106.82] 85.83 [66.7, 107.65] 0.388
Diabetes 41.2%
(3363)
43%
(681)
40.8%
(2682)
0.122 42.6%
(570)
44.7%
(598)
0.293
Hypertension 58.4%
(4759)
57.1%
(903)
58.7%
(3586)
0.266 57.4%
(769)
60.5%
(810)
0.116
Dyslipidemia 53.8%
(4386)
55.1%
(870)
53.5%
(3516)
0.280 55.9%
(748)
56.5%
(756)
0.758
Positive family history 30.0%
(2449)
27.7%
(440)
30.6%
(2009)
0.029 29.4%
(393)
29.4%
(394)
< 0.999
Opium 18.6%
(1509)
16.6%
(260)
19.1%
(1249)
0.026 17.2%
(230)
17.7%
(237)
0.760
Current cigarette smoking 20.4%
(1656)
18.0%
(283)
21.0%
(1373)
0.01 18.7%
(251)
18.9%
(253)
0.961
Ejection fraction
 ≥ 50 44.9%
(3612)
41.1%
(637)
45.8%
(2975)
< 0.001 42.2%
(565)
43.2%
(579)
0.612
 < 50 55.1%
(4429)
58.9%
(911)
54.2%
(3518)
  57.8%
(774)
56.8%
(760)
 
Left main stenosis 11.2%
(913)
11.7%
(186)
11.1%
(727)
0.490 11.3%
(151)
11.5%
(154)
0.903
Pre surgery PCI 10.2%
(834)
12.5%
(199)
9.7%
(635)
< 0.001 11.8%
(158)
12.2%
(164)
0.766
Renal failure 2.8%
(225)
4.0%
(63)
2.5%
(162)
< 0.001 3.4%
(45)
2.3%
(30)
0.103
COPD 3.7%
(302)
4.6%
(71)
3.5%
(231)
0.065 4.0%
(53)
3.7%
(49)
0.762
Cerebrovascular accident 10.1%
(820)
10.4%
(163)
10.0%
(657)
0.14 10.2%
(137)
11.4%
(153)
0.351
Urgent operation 1.2%
(98)
0.9%
(14)
1.3%
(84)
0.671 0.7%
(9)
1.1%
(15)
0.305
Previous myocardial infarction
 No history 70.2%
(5730)
73.1%
(1161)
69.5%
(4569)
0.001 72.0%
(964)
75.7%
(1014)
0.148
 ≤ 7 days 10.4%
(848)
10.1%
(160)
10.5%
(686)
  10.2%
(136)
9.3%
(125)
 
 8–21 days 7.1%
(582)
5.0%
(79)
7.7%
(503)
  5.3%
(71)
4.7%
(63)
 
 > 21 days 12.3%
(1003)
11.9%
(189)
12.4%
(814)
  12.5%
(168)
10.2%
(137)
 
  1. *P value < 0.05 considered as significant
  2. BMI body mass index, Hb hemoglobin, eGFR estimated glomerular filtration rate, PCI percutaneous coronary intervention, COPD chronic obstructive pulmonary disease