Table 3 The performance of qualitative and quantitative variables for predicting esophageal fistula in the primary and validation cohorts

Primary cohort

Y1

0.946 (0.902–0.990)

2.1^a

0.885

0.933

0.828

0.959

0.922

Y2

0.953 (0.909–0.997)

2.58^a

0.923

0.947

0.862

0.973

0.941

Trachea invasion

0.709 (0.579–0.838)

Yes

0.444

0.973

0.857

0.839

0.833

Tumor range

0.756 (0.660–0.853)

3/4–1

0.926

0.587

0.49

0.973

0.676

T stage

0.726 (0.600–0.852)

T4b

0.519

0.933

0.737

0.843

0.824

Location

0.696 (0.582–0.809)

Mid-thorax

0.778

0.613

0.885

0.42

0.657

Deep ulcer

0.874 (0.782–0.966)

Yes

0.815

0.933

0.815

0.933

0.902

Validation cohort

Y1

0.841 (0.758–0.924)

2.1^a

0.63

0.84

0.586

0.863

0.784

Y2

0.917 (0.864–0.969)

2.58^a

0.63

0.827

0.567

0.861

0.775

Trachea invasion

0.524 (0.392–0.655)

Yes

0.154

0.893

0.333

0.753

0.696

Tumor range

0.648 (0.531–0.745)

3/4–1

0.741

0.569

0.37

0.854

0.598

T stage

0.562 (0.429–0.696)

T4b

0.778

0.893

0.429

0.761

0.716

Location

0.584 (0.470–0.699)

Mid-thorax

0.63

0.587

0,354

0.815

0.598

Deep ulcer

0.767 (0.649–0.885)

Yes

0.667

0.88

0.148

0.867

0.676