From: Relationship between FEV1 change and patient-reported outcomes in randomised trials of inhaled bronchodilators for stable COPD: a systematic review
SGRQ
Study period
Data points, n
Correlation, r*
p value
Total score
All
49
-0.46
<0.001
3 months
16
-0.44
0.08
6 months
20
-0.61
0.004
12 months
19
-0.74
Symptoms
27
-0.34
Activity
-0.38
0.049
Impact
30
-0.50