Table 1 The clinical characteristics of the training set, internal validation set, and external validation set

Age (years)

67.0 (55.5–79.0)

48.0 (28.0–67.3)

66.0 (55.0–76.3)

42.0 (28.0–58.8)

66.5 (57.8–79.0)

51.0 (34.0–69.0)

Gender (n, %)

 Female

116 (32.1)

87 (30.0)

47 (35.1)

44 (35.5)

8 (16.7)

17 (27.4)

 Male

245 (67.9)

203 (70.0)

87 (64.9)

80 (64.5)

40 (83.3)

45 (73.6)

Smoke status (n, %)

 Non-smokers

216 (59.8)

186 (64.1)

86 (64.2)

87 (70.2)

27 (56.2)

41 (66.1)

 C/F smokers

145 (40.2)

104 (35.9)

48 (35.8)

37 (29.8)

21 (43.8)

21 (33.9)

Effusion

 WBC (× 10.⁹/L)

1.27 (0.42–3.85)

2.18 (1.22–3.70)

1.50 (0.40–5.17)

2.39 (1.42–3.89)

0.88 (0.4–2.93)

1.36 (0.57–2.95)

 Neutrophil (× 10.⁹/L)

0.23 (0.06–1.50)

0.14 (0.05–0.38)

0.25 (0.04–1.35)

0.18 (0.06–0.44)

0.24 (0.06–1.23)

0.13 (0.04–0.25)

 Lymphocyte (× 10.⁹/L)

 Total protein (g/L)

0.39 (0.14–1.21)

39.50 (25.25–48.80)

1.86 (0.95–2.95)

51.25 (48.00–54.30)

0.49 (0.15–1.57)

40.25 (26.30–51.93)

1.99 (1.12–3.28)

51.75 (48.25–55.23)

0.33 (0.12–1.21)

40.85 (25.55–48.40)

1.10 (0.36–2.30)

49.10 (45.18–52.53)

 Glucose (mmol/L)

6.82 (4.89–8.54)

5.39 (4.30–6.38)

6.50 (4.77–8.48)

5.55 (4.36–6.37)

7.06 (5.04–9.41)

5.52 (4.48–7.00)

 ADA (U/L)

10.50 (5.20–20.85)

42.25 (32.50–54.83)

10.00 (4.40–21.42)

44.00 (33.38–55.83)

12.00 (5.00–23.00)

43.50 (32.75–53.00)

 LDH (U/L)

228.0 (121.0–755.5)

441.0 (309.5–666.8)

301.0 (126.5–889.5)

450 (318.8–642.8)

387.5 (189.8–997.3)

506.5 (361.0–842.3)

 CA125 (U/ml)

1134.5 (546.9–2029.2)

995.1 (452.2–1638.7)

1096.5 (490.0–1855.0)

1031.0 (464.8–1630.4)

1205.7 (492–2102.5)

897.8 (437.9–1757.8)

 CA19-9 (U/ml)

2.00 (1.00–3.63)

2.50 (1.29–4.10)

2.00 (0.98–4.95)

2.50 (1.51–4.58)

2.15 (1.03–3.85)

2.20 (1.08–4.75)

Serum

 WBC (× 10.⁹/L)

7.50 (5.60–10.50)

6.18 (5.06–7.67)

7.52 (5.86–10.48)

6.40 (5.10–7.63)

6.55 (5.35–8.90)

5.95 (4.30–7.30)

 Neutrophil (× 10.⁹/L)

5.10 (3.10–8.10)

4.20 (3.30–5.50)

5.15 (4.00–7.65)

4.28 (3.40–5.44)

4.74 (3.78–6.98)

4.36 (2.80–5.51)

 Lymphocyte (× 10.⁹/L)

1.10 (0.70–1.50)

1.10 (0.80–1.40)

1.10 (0.80–1.50)

1.10 (0.80–1.42)

0.99 (0.69–1.38)

0.91 (0.56–1.24)

 hsCRP (mg/L)

27.04 (6.28–105.27)

44.48 (17.22–79.25)

30.54 (5.87–107.69)

42.84 (19.07–68.87)

56.68 (13.49–163.5)

68.80 (28.23–93.80)

 ESR (mm/h)

47.0 (22.5–69.0)

46.0 (27.0–69.0)

43.5 (19.0–66.3)

46.5 (33.0–65.0)

54.00 (25.00–73.50)

46.50 (30.00–65.25)

 ADA (U/L)

10.60 (7.80–14.80)

11.55 (8.68–14.80)

10.60 (7.70–13.53)

11.70 (9.20–15.25)

9.00 (7.00–13.00)

11.50 (9.00–15.00)

 LDH (U/L)

187.0 (156.0–232.5)

193.0 (165.0–239.0)

199.0 (160.8–245.3)

185.0 (156.0–226.0)

202.0 (163.0–250.8)

176.5 (161.8–207.0)

 CA125 (U/ml)

63.8 (28.4–148.7)

103.3 (55.7–183.8)

61.3 (30.1–129.7)

124.1 (54.1–192.1)

72.3 (42.2–169.6)

111.7 (64.4–211.4)

 CA19-9 (U/ml)

8.90 (4.25–16.20)

6.09 (3.18–10.53)

6.50 (3.98–15.50)

5.80 (3.60–10.30)

8.80 (4.30–13.00)

4.20 (2.18–9.40)