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Table 2 Distribution of potential confounders before and after matching

From: Targeted temperature management in cardiac arrest: survival evaluated by propensity score matching

  Before matching After matching
Control (n = 153) Treated (n = 183)   Control (n = 96) Treated (n = 96)  
Count/ Percenta/ Count/ Percenta/ Count/ Percenta/ Count/ Percenta/
[mean] (SD) [mean] (SD) P-value [mean] (SD) [mean] (SD) P-value
Age [64] (20) [59] (16) 0.01 [63] (18) [61] (17) 0.63
Male Gender 86 56% 140 77% <0.001 59 61% 70 73% 0.12
Shockable rhythm      <0.001      0.09
 No 102 67% 49 27%   56 58% 41 43%  
 Yes 41 27% 132 72%   38 40% 53 55%  
(Missing) 10 7% 2 1%   2 2% 2 2%  
Witnessed CA 111 73% 164 90% <0.001 76 79% 80 83% 0.58
Bystander CPR 72 47% 130 71% <0.001 52 54% 56 58% 0.66
Time CA to professional CPR [14.6] (25.5) [11.2] (16.8) 0.15 [7.1] (5.6) [8.0] (5.5) 0.32
(Missing) 12 8% 6 3% 0.11 6 6% 6 6% 1.00
Time CA to ROSC [27.2] (16.5) [26.7] (16.1) 0.77 [24.4] (13.8) [22.7] (12.6) 0.38
(Missing) 9 6% 16 9% 0.43 6 6% 8 8% 0.78
Smoking      0.001      0.44
 No 32 21% 39 21%   23 24% 18 19%  
 Ex-smoker 28 18% 47 26%   19 20% 19 20%  
 Smoker 37 24% 66 36%   27 28% 37 39%  
(Missing) 56 37% 31 17%   27 28% 22 23%  
Diabetes Mellitus      <0.001      0.69
 No 97 63% 155 85%   73 76% 79 82%  
 Type 1 5 3% 5 3%   4 4% 2 2%  
 Type 2 20 13% 20 11%   16 17% 12 12%  
(Missing) 31 20% 3 2%   3 3% 3 3%  
Hypertension      <0.001      0.83
 No 78 51% 116 63%   56 58% 57 59%  
 Yes 48 31% 62 34%   33 34% 34 35%  
(Missing) 27 18% 5 3%   7 7% 5 5%  
Previous myocardial infarction 42 27% 52 28% 0.94 30 31% 29 30% 1.00
  1. SD standard deviation, CA cardiac arrest, CPR cardiopulmonary resuscitation, ROSC return of spontaneous circulation
  2. aThe percentage values are based on patients with non-missing data