Table 5 Demographic characteristics of patients and postoperative functional recovery before matching

Sex

4.073

0.044

 Male

373

150

 Female

225

122

Age (years)

55.8±11.7

58.8±12.7

− 3.458

0.001

Diabetes mellitus

0.204

0.652

 No

405

180

 Yes

193

92

Hypertension

0.672

0.412

 No

406

177

 Yes

192

95

Smoking habit

0.212

0.645

 Nonsmoker

442

197

 Smoker

156

75

Current alcohol use

0.846

0.358

 No

423

184

 Yes

175

88

Previous abdominal surgery

0.093

0.760

 No

512

235

 Yes

86

37

Chronic obstructive pulmonary disease

0.064

0.801

 No

529

239

 Yes

69

33

BMI (kg/m²)

23.3±3.2

22.7±2.7

2.416

0.016

Preoperative anemia

1.826

0.177

 No

444

190

 Yes

154

82

Preoperative serum albumin level

39.1±4.5

38.1±4.4

3.055

0.002

ASA

0.725

0.395

 I–II

443

194

 ≥III

155

78

Tumor size

0.387

0.534

 <5 cm

306

133

 ≥5 cm

292

139

Operation time (min)

5.744

0.017

 <180

273

148

 ≥180

325

124

Blood loss (ml)

168.9±76.2

174.7±79.1

− 1.039

0.299

Grade of differentiation

12.860

0.002

 Well

92

49

 Moderate

355

127

 Poorly

151

96

Lymph node resected

23.9±9.6

24.9±9.4

-1.527

0.127

pTNM stage

3.808

0.149

 I

103

44

 II

262

138

 III

233

90

PPOI

19.470

0.000

 No

540

216

 Yes

58

56

First flatus

2.1±1.8

3.5±2.4

− 9.379

0.000

First semi-liquid diet

3.6±1.8

5.0±2.5

− 9.765

0.000

Length of stay

6.2±1.4

7.6±2.3

− 9.674

0.000