Table 2 Minimal Clinically Important Difference (MCID) for the Clinical COPD Questionnaire (CCQ) by patient referencing. Differences between CCQ scores for Days 1 and 3 grouped according to Global Rating of Change (GRC) as scored by patients on a scale of -7 to 7. Note that paired-sample t-tests were used for total CCQ scores and for symptom and functional domains; Wilcoxon signed rank test was used for the mental domain.
CCQ score category | Score difference: Day 1 minus Day 3 | ||
|---|---|---|---|
Mean ± SD | 95% confidence interval | p value | |
GRC +1 (n = 4) | |||
Total | 0.05 ± 0.49 | -0.73, 0.83 | 0.852 |
Symptoms | 0 ± 1.02 | -1.62, 1.62 | 1.0 |
Function | 0 ± 1.02 | -1.62, 1.62 | 1.0 |
Mental | 0.25§ | 0.414 | |
GRC +2 to +3 (n = 20) | |||
Total | 0.44 ± 0.66 | 0.13, 0.75 | 0.008* |
Symptoms | 0.74 ± 0.93 | 0.30, 1.17 | 0.002* |
Function | 0.26 ± 0.995 | -0.20, 0.72 | 0.253 |
Mental | 0.25§ | 0.398 | |
GRC +4 to +5 (n = 20) | |||
Total | 1.36 ± 1.07 | 0.86, 1.86 | <0.001* |
Symptoms | 1.46 ± 0.99 | 1.0, 1.92 | <0.001* |
Function | 1.31 ± 1.65 | 0.54, 2.08 | 0.002* |
Mental | 1.75§ | 0.023* | |
GRC +6 to +7 (n = 4) | |||
Total | 1.95 ± 0.87 | 0.56, 3.34 | 0.021* |
Symptoms | 2.37 ± 1.13 | 0.58, 4.17 | 0.024* |
Function | 2.31 ± 0.90 | 0.88, 3.74 | 0.014* |
Mental | -0.25§ | 0.655 | |