Table 3 Adjusted sub-distribution hazard ratios for depression during the first year post-diagnosis, and at the 1-year, 3-year, and 5-year landmark periods in breast cancer survivors compared to non-cancer control group

During the first year post-diagnosis

All ages

Control

99,834

2,826

98,440.30

28.7

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

59,340

5,304

55,866.60

94.9

3.22 (3.08–3.37)

3.23 (3.09–3.38)

3.23 (3.08–3.37)

Age ≤ 50

Control

49,312

952

48,849.20

19.5

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

29,922

2,567

28,275.50

90.8

4.51 (4.19–4.84)

4.51 (4.19–4.85)

4.51 (4.19–4.85)

Age > 50

Control

50,522

1,874

49,591.20

37.8

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

29,418

2,737

27,591.10

99.2

2.57 (2.42–2.72)

2.57 (2.43–2.72)

2.56 (2.42–2.71)

P for interaction

< 0.001

< 0.001

< 0.001

1-year landmark

All ages

Control

97,006

15,870

556,638.2

28.5

1 (ref.)

1 (ref.)

1 (ref .)

Breast cancer

53,879

9,188

301,244.6

30.5

1.04 (1.01–1.07)

1.04 (1.02–1.07)

1.04 (1.01–1.07)

Age ≤ 50

Control

48,359

6,087

284,242

21.4

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

27,293

3,949

155,560.4

25.4

1.15 (1.11–1.20)

1.15 (1.11–1.2)

1.16 (1.11–1.2)

Age > 50

Control

48,647

9,783

272,396.2

35.9

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

26,586

5,239

145,684.2

36

0.97 (0.94–1.01)

0.98 (0.94–1.01)

0.97 (0.94-1.00)

P for interaction

< 0.001

< 0.001

< 0.001

3-year landmark

All ages

Control

91,513

10,458

368,191.9

28.4

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

49,209

5,310

198,522.7

26.7

0.93 (0.90–0.96)

0.93 (0.90–0.96)

0.93 (0.90–0.96)

Age ≤ 50

Control

46,394

4,135

189,479.3

21.8

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

25,241

2,251

103,251.1

21.8

0.99 (0.90–1.04)

0.99 (0.94–1.04)

0.99 (0.94–1.04)

Age > 50

Control

45,119

6,323

178,712.6

35.3

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

23,968

3,059

95,271.6

32.1

0.89 (0.85–0.93)

0.89 (0.85–0.93)

0.89 (0.85–0.93)

P for interaction

0.002

0.003

0.002

5-year landmark

All ages

Control

76,469

5,521

194,148.2

28.4

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

40,972

2,802

105,234

26.6

0.92 (0.88–0.97)

0.93 (0.89–0.97)

0.93 (0.88–0.97)

Age ≤ 50

Control

39,485

2,232

100,639.4

22.2

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

21,342

1,163

55,131.1

21.1

0.98 (0.87–1.01)

0.94 (0.87–1.01)

0.94 (0.87–1.01)

Age > 50

Control

36,984

3,289

93,508.8

35.2

1 (ref.)

1 (ref.)

1 (ref.)

Breast cancer

19,630

1,639

50,102.9

32.7

0.92 (0.86–0.97)

0.92 (0.88–0.98)

0.92 (0.86–0.97)

P for interaction

0.63

0.73

0.66