Table 2 Crude hazard ratio of COPD patients’ serious events

Without GORD

With GORD

1.67

1.22 to 2.27^***

1.85

1.31 to 2.62^***

Male

1.12

0.8 to 1.56

1.18

0.81 to 1.72

Age 40 to 50

Age 51 to 60

3.48

1.31 to 9.28^*

1.48

0.58 to 3.76

Age 61 to 70

6.6

2.62 to 16.6^***

3.64

1.62 to 8.2^***

Age 71 to 80

9.92

4.00 to 24.6^***

5.02

2.27 to 11.1^***

Age ≥80

12.2

4.66 to 31.8^***

8.99

3.9 to 20.7^***

CCI = 0

CCI = 1 to 3

1.77

0.24 to 12.9

1.59

0.22 to 11.6

CCI = 4 to 6

3.09

0.43 to 22.4

2.3

0.32 to 16.8

CCI ≥7

9.59

1.33 to 68.9^*

7.13

0.99 to 51.5

Theophylline used

1.26

0.77 to 2.06

1.87

0.98 to 3.57

Proxy COPD severity

2.24

1.21 to 4.12^**

1.48

0.65 to 3.37

Residential area

 Urban

 Suburban

1.32

0.95 to 1.82

1.55

1.08 to 2.23

 Rural

0.89

0.50 to 1.60

1.14

0.61 to 2.12

Occupation categories

 Category 1

 Category 2

1.13

0.77 to 1.66

1.6

1.01 to 2.55^*

 Category 2

1.28

0.84 to 1.94

1.76

1.07 to 2.90^*

 No fee

 1to 19,199

0.76

0.51 to 1.12

1.04

0.67 to 1.61

 19,200 to 23,999

0.63

0.43 to 0.92^*

0.77

0.5 to 1.2

  ≥ 24,000

0.29

0.15 to 0.56^***

0.24

0.1 to 0.56^***