Table 3 Cox proportional hazards regression analysis evaluating the effect of ICS cessation and variables associated with the time to first exacerbation in the 1-year outcome period

Group

 Control

4184

2008 (47.9%)

1

Ref

 ICS cessation

1046

501 (47.9%)

1.02

0.92 to 1.12

1.04

0.94 to 1.15

0.441

Sex

 Female

2330

1190 (51.1%)

1

Ref

 Male

2900

1319 (45.5%)

0.85

0.79 to 0.92

GOLD severity category

 Mild

525

236 (44.9%)

1

Ref

 Moderate

2173

1019 (46.9%)

1.05

0.91 to 1.21

 Severe

1576

790 (50.1%)

1.15

0.99 to 1.33

 Very severe

485

258 (53.2%)

1.26

1.06 to 1.51

Blood eosinophil count

 < 0.1

370

173 (46.7%)

1

Ref

 ≥ 0.1 to < 0.3

2947

1452 (49.3%)

1.07

0.91 to 1.25

 ≥ 0.3

970

490 (50.5%)

1.1

0.93 to 1.31

CAT score

 0–9

275

108 (39.2%)

1

Ref

 10–19

457

206 (45.1%)

1.2

0.95 to 1.52

 20–29

318

155 (48.7%)

1.33

1.04 to 1.70

 30–40

124

74 (59.7%)

1.82

1.35 to 2.44

mMRC dyspnea scale

 0

292

129 (44.2%)

1

Ref

 1

1538

686 (44.6%)

1.04

0.86 to 1.25

 2

1648

830 (50.3%)

1.2

1.00 to 1.44

 3

1168

579 (49.6%)

1.19

0.98 to 1.44

 4

244

124 (50.8%)

1.23

0.96 to 1.57

Asthma diagnosis pre-baseline

 No

3957

1864 (47.1%)

1

Ref

 Yes

1273

645 (50.6%)

1.13

1.03 to 1.23

Respiratory consultations in baseline year

 0

179

52 (29.0%)

1

Ref

 1–2

2116

777 (36.7%)

1.33

1.00 to 1.76

 3–4

1434

677 (47.2%)

1.84

1.39 to 2.44

 5+

1501

1003 (66.8%)

3.33

2.52 to 4.40

Exacerbations managed in primary care in baseline year

 0

2573

851 (33.1%)

1

Ref

 1

1404

732 (52.1%)

1.81

1.64 to 2.00

1.74

1.57 to 1.93

< 0.001

 2

637

421 (66.1%)

2.81

2.50 to 3.16

2.57

2.26 to 2.93

< 0.001

 3+

616

505 (81.9%)

4.57

4.09 to 5.10

4.04

3.55 to 4.59

< 0.001

Exacerbations requiring A&E attendance or hospitalisation in baseline year

 0

4885

2302 (47.1%)

1

Ref

 1+

345

207 (60.0%)

1.49

1.29 to 1.71

Antibiotics prescriptions in baseline year

 0

2659

895 (33.6%)

1

Ref

 1

1298

682 (52.5%)

1.81

1.64 to 2.00

 2

600

390 (65.0%)

2.6

2.31 to 2.93

 3+

673

542 (80.5%)

4.29

3.86 to 4.78

OCS prescriptions in baseline year

 0

2108

769 (36.5%)

1

Ref

 1

992

454 (45.7%)

1.34

1.19 to 1.50

1.02

0.90 to 1.15

0.791

 2

680

375 (55.1%)

1.75

1.55 to 1.98

1.14

1.00 to 1.30

0.053

 3+

1450

911 (62.8%)

2.21

2.01 to 2.44

1.22

1.09 to 1.37

< 0.001

ICS medication possession ratio in baseline year

 ≥ 70–< 80%

1559

728 (46.7%)

1

Ref

 ≥ 80–< 90%

1049

491 (46.8%)

1

0.90 to 1.13

1

0.90 to 1.13

0.947

 ≥ 90–< 100%

1254

599 (47.7%)

1.05

0.94 to 1.17

0.99

0.88 to 1.10

0.804

 ≥100%

1368

691 (50.5%)

1.12

1.01 to 1.24

1.03

0.93 to 1.15

0.55

Time since first COPD diagnosis, year

 < 1

321

132 (41.1%)

1

Ref

 ≥1–< 5

1360

607 (44.6%)

1.11

0.92 to 1.34

 ≥ 5–< 10

1741

862 (49.5%)

1.29

1.07 to 1.55

 ≥ 10–< 15

1017

502 (49.3%)

1.29

1.07 to 1.56

 ≥ 15

639

330 (51.6%)

1.38

1.13 to 1.69

Time on triple therapy, year

 < 1

896

386 (43.1%)

1

Ref

 ≥1–< 3

1626

739 (45.4%)

1.1

0.97 to 1.24

 ≥ 3–< 5

1234

596 (48.3%)

1.2

1.05 to 1.36

 ≥ 5

1474

788 (53.4%)

1.38

1.22 to 1.55