Table 1 Comparisons of demographic, perioperative and laboratory indicators between SSI and Non-SSI patients in the training and validation set.

From: Development and validation of a clinical nomogram prediction model for surgical site infection following lumbar disc herniation surgery

Variables

Training set

 

Validation set

 

SSI

Non-SSI

P-value

SSI

Non-SSI

P-value

(N = 165)

(N = 341)

(N = 76)

(N = 141)

Demographic Indicators

Gender

  

0.20

  

1.00

Female

79 (47.88%)

141 (41.35%)

 

34 (44.74%)

64 (45.39%)

 

Male

86 (52.12%)

200 (58.65%)

 

42 (55.26%)

77 (54.61%)

 

Age

  

0.001

  

0.21

<60 years

98 (59.39%)

253 (74.19%)

 

52 (68.42%)

109 (77.30%)

 

≥ 60 years

67 (40.61%)

88 (25.81%)

 

24 (31.58%)

32 (22.70%)

 

Smoke status

  

0.72

  

0.03

Never

107 (64.85%)

214 (62.76%)

 

41 (53.95%)

99 (70.21%)

 

Ever/current

58 (35.15%)

127 (37.24%)

 

35 (46.05%)

42 (29.79%)

 

Drink status

  

0.35

  

0.72

Never

134 (81.21%)

263 (77.13%)

 

58 (76.32%)

103 (73.05%)

 

Ever/current

31 (18.79%)

78 (22.87%)

 

18 (23.68%)

38 (26.95%)

 

HBP

  

0.63

  

0.03

No

109 (66.06%)

234 (68.62%)

 

47 (61.84%)

108 (76.60%)

 

Yes

56 (33.94%)

107 (31.38%)

 

29 (38.16%)

33 (23.40%)

 

DM

  

0.001

  

0.001

No

97 (58.79%)

251 (73.61%)

 

40 (52.63%)

106 (75.18%)

 

Yes

68 (41.21%)

90 (26.39%)

 

36 (47.37%)

35 (24.82%)

 

BMI

  

<0.001

  

0.004

<28 kg/m2

51 (30.91%)

185 (54.25%)

 

25 (32.89%)

77 (54.61%)

 

≥ 28 kg/m2

114 (69.09%)

156 (45.75%)

 

51 (67.11%)

64 (45.39%)

 

Perioperative indicators

MS:

  

0.96

  

0.10

No

115 (69.70%)

240 (70.38%)

 

47 (61.84%)

104 (73.76%)

 

Yes

50 (30.30%)

101 (29.62%)

 

29 (38.16%)

37 (26.24%)

 

Implant

  

0.15

  

0.10

No

18 (10.91%)

55 (16.13%)

 

9 (11.84%)

31 (21.99%)

 

Yes

147 (89.09%)

286 (83.87%)

 

67 (88.16%)

110 (78.01%)

 

OT:

  

0.03

  

0.56

< 3 h

78 (47.27%)

197 (57.77%)

 

47 (61.84%)

80 (56.74%)

 

≥ 3 h

87 (52.73%)

144 (42.23%)

 

29 (38.16%)

61 (43.26%)

 

IBL

  

0.09

  

1.00

< 200 ml

144 (87.27%)

315 (92.38%)

 

68 (89.47%)

127 (90.07%)

 

≥ 200 ml

21 (12.73%)

26 (7.62%)

 

8 (10.53%)

14 (9.93%)

 

PSD

  

<0.001

  

<0.001

< 300 ml

21 (12.73%)

165 (48.39%)

 

12 (15.79%)

70 (49.65%)

 

≥ 300 ml

144 (87.27%)

176 (51.61%)

 

64 (84.21%)

71 (50.35%)

 

GS

  

<0.001

  

0.005

No

12 (7.27%)

84 (24.63%)

 

4 (5.26%)

29 (20.57%)

 

Yes

153 (92.73%)

257 (75.37%)

 

72 (94.74%)

112 (79.43%)

 

PTAG

  

0.60

  

0.37

No

43 (26.06%)

98 (28.74%)

 

18 (23.68%)

43 (30.50%)

 

Yes

122 (73.94%)

243 (71.26%)

 

58 (76.32%)

98 (69.50%)

 

NPTA

  

0.009

  

0.02

No

110 (66.67%)

266 (78.01%)

 

45 (59.21%)

106 (75.18%)

 

Yes

55 (33.33%)

75 (21.99%)

 

31 (40.79%)

35 (24.82%)

 

Laboratory indicators

PTHB

  

0.32

  

0.09

Normal

57 (34.55%)

135 (39.59%)

 

32 (42.11%)

42 (29.79%)

 

Abnormal

108 (65.45%)

206 (60.41%)

 

44 (57.89%)

99 (70.21%)

 

PTSA

  

0.004

  

0.002

Normal

91 (55.15%)

234 (68.62%)

 

36 (47.37%)

98 (69.50%)

 

Abnormal

74 (44.85%)

107 (31.38%)

 

40 (52.63%)

43 (30.50%)

 

LKF

  

0.71

  

0.09

Normal

67 (40.61%)

146 (42.82%)

 

40 (52.63%)

56 (39.72%)

 

Abnormal

98 (59.39%)

195 (57.18%)

 

36 (47.37%)

85 (60.28%)

 

K+

  

0.001

  

0.65

Normal

43 (26.06%)

141 (41.35%)

 

27 (35.53%)

56 (39.72%)

 

Abnormal

122 (73.94%)

200 (58.65%)

 

49 (64.47%)

85 (60.28%)

 

Ca+

  

0.18

  

0.37

Normal

96 (58.18%)

221 (64.81%)

 

43 (56.58%)

90 (63.83%)

 

Abnormal

69 (41.82%)

120 (35.19%)

 

33 (43.42%)

51 (36.17%)

 

TT

  

<0.001

  

<0.001

Normal

56 (33.94%)

251 (73.61%)

 

39 (51.32%)

108 (76.60%)

 

Abnormal

109 (66.06%)

90 (26.39%)

 

37 (48.68%)

33 (23.40%)

 
  1. SSI surgical site infection, HBP high blood pressure, DM diabetes mellitus, BMI body mass index, MS multi-stage surgery, OT operation time, IBL intraoperative blood loss, PSD postoperative suction drainagen, GS gelatin sponge, PTAG postoperative anticoagulation, NPTA none-preoperative antibiotic, PTHB postoperative hemoglobin, PTSA postoperative serum albumin, LKF liver and kidney function, TT thrombin time. Categorical variables were presented as number and percentage (n, %). The bold text means that the P value was < 0.05.