Background
Patients and methods
Study subjects
Study design and data collection
Determining the MCID
Data analysis
Results
Patient characteristics
Baseline all patients N = 451 | Patients with complete follow-up N = 309 | Patients with incomplete follow-up N = 142 | Significance testing | |
---|---|---|---|---|
Age (years)a | 57.9 ± 6.6 | 58.1 ± 6.5 | 57.5 ± 6.6 | p = 0.39 |
Gender (male)b | 65.0 | 63.8 | 67.6 | p = 0.43 |
FEV1%preda | 50.4 ± 15.1 | 50.6 ± 14.9 | 50.0 ± 15.6 | p = 0.72 |
GOLD IIb | 227 (50.3) | 158 (51.1) | 69 (48.6) | |
GOLD IIIb | 176 (39.0) | 121 (39.2) | 55 (38.7) | p = 0.63 |
GOLD IVb | 48 (10.6) | 30 (9.7) | 18 (12.7) | |
Smoking pack years a | 42.6 ± 23.5 | 41.1 ± 23.1 | 45.9 ± 24.0 | p = 0.05 |
CAT a | 20.2 ± 7.3 | 20.0 ± 7.6 | 20.8 ± 6.8 | p = 0.28 |
CCQ Totala | 2.9 ± 1.2 | 2.8 ± 1.2 | 3.0 ± 1.1 | p = 0.06 |
SGRQ Totala | 50.7 ± 17.3 | 49.6 ± 17.8 | 53.0 ± 16.2 | p = 0.05 |
Health status scores
N | CAT | CAT Standardized | CCQ Total | CCQ Total Standardized | SGRQ Total | ||
---|---|---|---|---|---|---|---|
Change at discharge (T1) | 451 | − 3.1* (− 3.6 to − 2.6) | − 7.8* (− 9.1 to − 6.5) | −0.6* (− 0.7 to − 0.5) | − 9.7* (− 11.2 to − 8.3) | − 9.0* (− 10.2 to − 7.9) | |
Change after 3 months (T2) | 355 | − 1.4* (− 2.2 to − 0.7) | −3.6* (− 5.4 to − 1.8) | − 0.3* (− 0.4 to − 0.2) | − 4.3* (− 6.2 to − 2.5) | − 5.4* (− 6.9 to − 3.8) | |
Change after 6 months (T3) | 319 | −0.9* (− 1.7 to − 0.1) | −2.3* (− 4.2 to − 0.4) | − 0.1 (− 0.2 to zero) | −1.8 (− 3.8 to + 0.2) | − 4.9* (− 6.5 to − 3.2) | |
Change after 9 months (T4) | 304 | −1.1* (− 1.9 to − 0.4) | −2.9* (− 4.8 to − 0.9) | − 0.2* (− 0.4 to − 0.1) | − 3.8* (− 5.8 to − 1.8) | − 5.2* (− 6.9 to − 3.4) | |
Change after 12 months (T5) | 309 | −0.9* (− 1.7 to − 0.1) | − 2.2* (− 4.2 to − 0.3) | − 0.2* (− 0.3 to − 0.1) | − 2.7* (− 4.7 to − 0.7) | −3.9* (− 5.7 to − 2.2) |
Minimal clinically important differences for CAT, CCQ and SGRQ
15-point GRC T1 | 15-point GRC T2 | 15-point GRC T3 | 15-point GRC T4 | 15-point GRC T5 | Five-point GRC T5 | |
---|---|---|---|---|---|---|
N of Patients | 451 | 355 | 319 | 304 | 309 | 309 |
CAT change score | − 0.23 | − 0.33 | − 0.40 | − 0.43 | − 0.41 | 0.46 |
CCQ total change score | −0.29 | − 0.42 | − 0.44 | −0.48 | − 0.47 |
0.50
|
SGRQ total change score | −0.30 | −0.48 |
− 0.51
|
−0.58
|
− 0.54
|
0.57
|
Measurement period | N | CAT | CAT Standardized | CCQ Total | CCQ Total Standardized | SGRQ Total |
---|---|---|---|---|---|---|
15-point GRC T1-T0 | 196 | −3.1*±5.3 (− 3.9 to − 2.4) | − 7.8*±13.2 (− 9.7 to − 5.9) | −0.6*±0.8 (− 0.7 to − 0.4) | − 9.3*±14.0 (− 11.3 to − 7.3) | − 8.4*±11.8 (− 10.1 to − 6.7) |
15-point GRC T2-T0 | 107 | −2.7*±6.4 (− 4.0 to − 1.5) | −6.9*±16.1 (− 9.9 to − 3.8) | −0.4*±1.0 (− 0.6 to − 0.2) | − 7.3*±16.8 (− 10.5 to − 4.0) | − 7.6*±13.8 (− 10.2 to − 4.9) |
15-point GRC T3-T0 | 96 | − 2.7*±6.7 (− 4.1 to − 1.4) | −6.8*±16.7 (− 10.2 to − 3.5) | −0.4*±1.1 (− 0.6 to − 0.2) | − 7.0*±18.0 (− 10.6 to − 3.3) | − 9.2*±14.0 (− 12.1 to − 6.3) |
15-point GRC T4-T0 | 80 | −2.3*±6.1 (− 3.7 to − 1.0) | −5.8*±15.2 (− 9.2 to − 2.4) | −0.5*±0.8 (− 0.7 to − 0.3) | − 7.6*±13.8 (− 10.8 to − 4.7) | − 10.3*±12.9 (− 13.2 to − 7.4) |
15-point GRC T5-T0 | 88 | −2.8*±6.7 (− 4.2 to − 1.4) | −7.0*±16.7 (− 10.5 to − 3.5) | − 0.5*±1.0 (− 0.7 to − 0.3) | − 8.3*±16.3 (− 11.7 to − 4.8) | − 8.8*±14.1 (− 11.8 to − 5.8) |
Five-point GRC T5-T0 | 81 | −1.4*±5.9 (− 2.7 to − 0.1) | −3.5*±14.7 (− 6.7 to − 0.3) | −0.3*±0.8 (− 0.5 to − 0.2) | − 5.5*±13.8 (− 8.7 to − 2.5) | −7.7*±12.9 (− 10.5 to − 4.8) |
Tests of significance between MCID estimates
15-point GRC T0-T1 | 15-point GRC T0-T2 | 15-point GRC T0-T3 | 15-point GRC T0-T4 | 15-point GRC T0-T5 | Five-point GRC T0-T5 | |
---|---|---|---|---|---|---|
CAT | ||||||
Mean change | −3.1 | −2.7 | − 2.7 | − 2.3 | −2.8 | −1.4 |
SD of the change | 5.3 | 6.4 | 6.7 | 6.1 | 6.7 | 5.9 |
N of patients | 196 | 107 | 96 | 80 | 88 | 81 |
ICC | 0.7 | 0.6 | 0.5 | 0.6 | 0.5 | 0.6 |
Z score required | 0.62 | 0.98 | 0.98 | 0.98 | 0.98 | 0.98 |
Standard Error | 0.4 | 0.6 | 0.7 | 0.7 | 0.7 | 0.7 |
CI | −3.4 to −2.9 | −3.4 to −2.1 | −3.4 to −2.1 | −3.0 to −1.6 | −3.5 to − 2.1 | −2.0 to − 0.8 |
Standardized mean change and CI | −7.8 (− 8.4 to − 7.2) | −6.9 (− 8.4 to −5.3) | −6.8 (−8.5 to −5.2) | −5.8 (− 7.4 to −4.1) | − 7.0 (− 8.8 to − 5.3) | − 3.5 (− 5.1 to − 1.90) |
CCQ Total | ||||||
Mean change | −0.6 | − 0.4 | − 0.4 | − 0.5 | −0.5 | − 0.3 |
SD of the change | 0.8 | 1.0 | 1.1 | 0.8 | 1.0 | 0.8 |
N of patients | 196 | 107 | 96 | 80 | 88 | 81 |
ICC | 0.7 | 0.6 | 0.5 | 0.7 | 0.5 | 0.6 |
Z score required | 0.62 | 0.98 | 0.98 | 0.62 | 0.98 | 0.98 |
Standard Error | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
CI | −0.7 to −0.5 | −0.5 to −0.3 | −0.5 to −0.3 | −0.6 to − 0.4 | −0.6 to − 0.4 | −0.4 to 0.2 |
Standardized mean change and CI | −9.3 (−10.0 to −8.7) | −7.3 (−9.0 to −5.7) | −7.0 (− 8.8 to −5.2) | −7.7 (− 8.7 to −6.7) | − 8.3 (− 10.0 to − 6.7) | − 5.5 (− 7.0 to −4.0) |
SGRQ Total | ||||||
Mean change | −8.4 | −7.6 | − 9.2 | − 10.3 | −8.8 | − 7.7 |
SD of the change | 11.8 | 13.8 | 14.0 | 12.9 | 14.1 | 12.9 |
N of patients | 196 | 107 | 96 | 80 | 88 | 81 |
ICC | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 | 0.6 |
Z score required | 0.62 | 0.62 | 0.62 | 0.62 | 0.98 | 0.98 |
Standard Error | 0.8 | 1.3 | 1.4 | 1.4 | 1.5 | 1.4 |
CI | −8.9 to −7.9 | −8.4 to −6.8 | −10.1 to −8.3 | −11.2 to −9.4 | −10.3 to − 7.4 | −9.1 to − 6.3 |