Table 4 Univariable analysis and multivariable logistic regression of PPOI

Baseline characteristics

 Sex

  Female

Ref

  Male

1.331 (0.808–2.192)

0.261

 Age (years)

   < 65

Ref

   ≥ 65

2.060 (1.240–3.421)

0.005

1.816 (1.040–3.172)

0.036

 Smoking history

  Yes

1.128 (0.648–1.967)

0.670

  No

Ref

 Drinking history

  Yes

1.275 (0.634–2.560)

0.495

  No

Ref

 Hypertension

  Yes

1.062 (0.615–1.834)

0.829

  No

Ref

 Diabetes

  Yes

0.527 (0.204–1.362)

0.186

  No

Ref

 Respiratory disease

  Yes

0.811 (0.334–1.969)

0.643

  No

Ref

 Cardiac disease

  Yes

0.907 (0.309–2.659)

0.858

  No

Ref

 Previous abdominal surgery

  Yes

1.775 (0.997–3.158)

0.051

1.576 (0.836–6.309)

0.16

  No

Ref

 ASA score

  I

Ref

  II

1.044 (0.619–1.759)

0.873

  III

0.778 (0.262–2.306)

0.650

 Hypoproteinemia

  Yes

3.465 (1.742–6.893)

 < 0.001

2.565 (1.183–5.563)

0.017

  No

Ref

 Anemia

  Yes

1.748 (0.983–3.110)

0.057

1.322 (0.642–2.722)

0.449

  No

Ref

 Hypokalaemia

  Yes

2.333 (0.954–5.705)

0.063

2.361 (0.883–6.309)

0.087

  No

Ref

 Narrow pelvis

  Yes

1.624 (0.777–3.397)

0.198

  No

Ref

 Large MFA

  Yes

1.225 (0.722–2.077)

0.452

  No

Ref

 Body mass index (kg/m²)

   < 25

Ref

   ≥ 25

1.479 (0.900–2.431)

0.123

 Visceral obesity

  Yes

1.412 (0.822–2.426)

0.212

  No

Ref

 Sarcopenia

  Yes

1.491 (0.870–2.553)

0.146

  No

Ref

 Preoperative chemotherapy

  Yes

1.227 (0.553–2.725)

0.615

  No

Ref

 Preoperative radiotherapy

  Yes

1.400 (0.596–3.289)

0.440

  No

Ref

 Surgical difficulty

  High

3.492 (1.821–6.698)

 < 0.001

2.934 (1.406–6.121)

0.004

  Low

Ref

Intraoperative characteristics

 Surgery type

  Robotic-assisted

0.884 (0.534–1.464)

0.632

  Laparoscopic

Ref

 Diverting ileostomy

  Yes

0.709 (0.422–1.191)

0.194

  No

Ref

 Specimen extraction approaches

  Conventional extraction

Ref

  NOSES

1.242 (0.634–2.433)

0.527

 Operation time (min)

   < 180

Ref

   ≥ 180

1.773 (1.071–2.934)

0.026

1.427 (0.794–2.565)

0.234

 Estimated blood loss (ml)

   < 100

Ref

   ≥ 100

2.444 (1.206–4.956)

0.013

1.733 (0.779–3.855)

0.178

 Conversion

  Yes

3.441 (1.009–11.736)

0.048

3.853 (0.995–14.925)

0.051

  No

Ref

Pathological characteristics

 Tumor differentiation

  Poor

Ref

  Moderate

0.694 (0.341–1.412)

0.313

  High

0.818 (0.314–2.133)

0.681

 Tumor height

  Low

1.372 (0.828–2.273)

0.220

  Middle

Ref

 Tumor diameter (cm)

   ≤ 5

Ref

   > 5

1.649 (0.929–2.928)

0.088

0.864 (0.438–1.708)

0.675

 Tumor stage

  I

Ref

  II

0.974 (0.494–1.921)

0.939

  III

1.105 (0.555–2.200)

0.777

Postoperative characteristics

 Postoperative use of opioid analgesic

  Yes

2.849 (1.710–4.747)

 < 0.001

2.624 (1.513–4.553)

0.001

  No

Ref

 Postoperative transfusion

  Yes

2.333 (0.954–5.705)

0.063

1.406 (0.464–4.259)

0.547

  No

Ref