Table 3 Scoring systems used for identifying complicated appendicitis

1. Bröker et al. [32]

CRP

≥ 3.0 (1)

2/2

Duration of symptoms

≥ 2 days (1)

2. Imaoka et al. [28]

Temp

≥ 37.4 °C (1)

1/3

CRP

≥ 4.7 (1)

Periappendiceal fluid

Yes (1)

3. Khan et al. [16]

Age

40–59 years (1)

2/4

≥ 60 years (2)

Duration of symptoms

≥ 2 days (1)

Appendicolith

Yes (1)

4. TH Kim et al. [33]

Appendiceal diameter

> 10 mm (1)

3/4

Ascites

Yes (1)

Fat stranding

Yes (1)

CRP

> 5.0 mg/dL (1)

5. Kang et al. [34]

Temp

≥ 37.9 °C (1)

4/8

Abdominal pain score

4–6 (1), ≥ 7 (2)

WBC count

> 13,660/μL (1)

NLR

≥ 10.9 (1)

CRP

≥ 6.6 (3)

6. Atema et al. [31]

Age

≥ 45 years (2)

7/22

Temp

≤ 37.0 °C (0)

37.1–37.9 °C (2)

≥ 38.0 °C (4)

Duration of symptoms

≥ 48 h (2)

WBC count

> 13,000/μL (2)

CRP (mg/dL)

≤ 5.0 (0)

5.0–10.0 (1)

> 10.0 (2)

Extraluminal free air

Present (5)

Periappendiceal fluid

Present (2)

Appendicolith

Present (2)

7. Avanesov et al. [36]

Age

≥ 52 years (1)

2/10

Temp

≥ 37.5 °C (1)

Duration of symptoms

≥ 48 h (1)

Appendix diameter

≥ 14 mm (1)

Periappendiceal fluid

Present (2)

Extraluminal air present

Present (1)

Abscess

Present (3)

8. HY Kim et al. [37]

Segmented neutrophils

≥ 81% (1)

3/6

Contrast-enhancement of the appendiceal wall

Defect (1)

Abscess

Present (1)

Fat stranding

Moderate or severe (1)

Appendiceal diameter

≥ 10 mm (1)

Extraluminal air

Present (1)

9. Model 1 (our model)

CRP (mg/dL)

3.0–5.9 (2)

6/10

≥ 6.0 mg/dL (3)

Fat stranding

Grade 1 (3)

Grade 2 (4)

Grade 3 (5)

Appendicolith

Present (1)

Ascites

Present (1)

10. Model 2 (our model)

CRP (mg/dL)

3.0–5.9 (2)

6/10

≥ 6.0 mg/dL (3)

Fat stranding

Grade 1 (3)

Grade 2 (4)

Grade 3 (5)

NLR

> 10 (1)

Ascites

Present (1)