Table 2 Univariate and multivariate analyses of overall survival (OS) for patients in training set.

Year at diagnosis

NI

2004–2007

2008–2011

2012–2015

Insured status

NI

Uninsured/unknown

Any medicaid/insured

Age

˂65

Reference

 ≥ 65

1.622 (1.452, 1.813)

˂0.001

Marital status^a

Unmarried

Reference

Married

0.869 (0.783, 0.964)

0.008

Gender

NI

Female

Male

Race

NI

Black

White

Other

Primary site

Cecum–transverse colon

Reference

Descending colon–sigmoid

1.188 (1.020, 1.385)

0.027

Multiple

1.406 (0.967, 2.044)

0.074

Rectum

1.227 (1.055, 1.434)

0.010

Unknown

1.237 (0.775, 1.974)

0.372

Grade

Grade I/II

Reference

Grade III/IV

1.364 (1.061, 1.753)

0.015

Unknown

1.407 (1.060, 1.868)

0.018

Tumor size

 ≤ 5 cm

Reference

˃5 cm

0.950 (0.845, 1.067)

0.387

Unknown

1.197 (1.016, 1.411)

0.032

T stage

T0-Tis

Reference

T1

1.134 (0.387, 3.324)

0.819

T2

1.881 (0.679, 5.209)

0.224

T3

2.330 (0.861, 6.304)

0.096

T4

3.306 (1.221, 8.952)

0.019

N stage

 < 0.001

N0

Reference

N1

1.716 (1.457, 2.021)

 < 0.001

N2

2.898 (2.479, 3.388)

 < 0.001

M stage

M0

Reference

M1

2.377 (2.104, 2.685)

 < 0.001

Surgery

 < 0.001

No surgery

Reference

Local tumor excision/partial colectomy

0.468 (0.365, 0.599)

 < 0.001

Total colectomy

0.552 (0.429, 0.712)

 < 0.001

Lymph node dissection

 < 0.001

None or Biopsy

Reference

1 to 3

0.782 (0.561, 1.091)

0.148

 ≥ 4

0.573 (0.462, 0.710)

 < 0.001

Chemotherapy

No/unknown

Reference

Yes

0.583 (0.519, 0.654)

 < 0.001

Radiotherapy

No/unknown

Yes