Table 4 IR and RR of the occurrence of CERO in tiotropium and placebo groups for GOLD stage II, and combined GOLD stages III and IV over a 4-year period

Year

N (%)

Patient-year

IR^a

N (%)

Patient-year

IR^a

RR

p-value

(95 % CI)

1

114 (7)

1312.9

8.7

158 (10)

1255.7

12.6

0.69

0.0025

(0.54–0.88)

2

187 (12)

2543.0

7.4

242 (15)

2408.5

10.0

0.73

0.0013

(0.60–0.89)

3

249 (16)

3709.7

6.7

312 (20)

3483.4

9.0

0.75

0.0007

(0.63–0.89)

4

304 (20)

4818.7

6.3

361 (23)

4501.6

8.0

0.79

0.0021

(0.68–0.92)

Year

N (%)

Patient-year

IR^a

N (%)

Patient-year

IR^a

RR

p-value

(95 % CI)

1

315 (20)

1354.3

23.3

385 (24)

1340.5

28.7

0.81

0.0055

(0.70–0.94)

2

465 (30)

2520.0

18.5

541 (34)

2476.8

21.8

0.84

0.0077

(0.75–0.96)

3

579 (37)

3547.6

16.3

659 (41)

3474.6

19.0

0.86

0.0084

(0.77–0.96)

4

675 (43)

4475.1

15.1

743 (46)

4378.0

17.0

0.89

0.0266

(0.80–0.99)