Table 2 Mortality, MRR, and interaction contrasts for CRC patients compared with persons in a matched population-based comparison cohort, overall and by CCI score

From: Does comorbidity interact with colorectal cancer to increase mortality? A nationwide population-based cohort study

CCI score

Cohort

No. of persons

No. of deaths

Person-years

Standardised mortality rates per 1000 person-years (95% CI)

Adjusted MRRs a (95% CI)

Interaction contrast (95% CI)

Proportion of the mortality explained by interaction

0–1 Year of follow-up

All

CRC

56 963

17 089

45 559

400

(394, 406)

8.3 (8.1, 8.5)

NA

All

Comparison

271 670

11 962

265 223

48

(47, 48)

Ref.

NA

0

CRC

34 918

8881

29 245

351

(343, 359)

15 (14, 15)

Ref.

0

Comparison

172 041

3652

170 008

27

(26, 28)

Ref.

1

CRC

9747

3254

7509

415

(401, 430)

7.4 (7.0, 7.7)

39

(22, 55)

9.4%

1

Comparison

47 139

2755

45 723

53

(51, 55)

Ref.

2–3

CRC

9522

3548

7035

489

(447, 530)

5.1 (4.9, 5.3)

79

(36, 121)

16%

2–3

Comparison

44 788

4234

42 521

86

(83, 89)

Ref.

4+

CRC

2776

1406

1771

761

(715, 807)

3.9 (3.7, 4.3)

262

(215, 310)

34%

4+

Comparison

7702

1321

6971

175

(165, 185)

Ref.

Two to 5 years of follow-up

All

CRC

39 862

14 274

102 813

143

(141, 146)

3.0 (2.9, 3.0)

NA

All

Comparison

258 729

40 310

808 019

50

(49, 50)

Ref.

NA

0

CRC

26 029

8606

69 909

131

(128 134)

4.2 (4.1, 4.3)

Ref.

0

Comparison

167 766

17 549

549 904

36

(36, 37)

Ref.

1

CRC

6490

2482

16 193

146

(140, 152)

2.3 (2.2, 2.4)

−9.8

(−17, −3.1)

NA

1

Comparison

44 215

9585

131 313

61

(60, 62)

Ref.

2–3

CRC

5973

2491

13 917

172

(165, 179)

2.0 (1.9, 2.0)

−3.0

(−11, 4.9)

NA

2–3

Comparison

40 390

10 902

111 329

80

(79, 82)

Ref.

4+

CRC

1370

695

2793

261

(231, 290)

1.7 (1.6, 1.8)

37

(7.0, 68)

14%

4+

Comparison

6358

2274

15 473

129

(123, 134)

Ref.

  1. Abbreviations: CCI=Charlson Comorbidity Index; CI=confidence interval; CRC=colorectal cancer; MRR=mortality rate ratios; NA=not applicable; Ref.=reference.
  2. aAdjusted for age, gender, and CRC/index year. For the overall analysis, we also adjusted for CCI scores.