Distribution characteristics and reliability estimates of the St George's Respiratory Questionnaire scales in the general population weighted sample
| Symptoms | Activity | Impacts | Overall | |
| Mean | 9.67 | 13.40 | 4.73 | 8.41 |
| sd | 13.24 | 17.63 | 9.92 | 11.33 |
| Observed range | 0–92.8 | 0–100 | 0–79.7 | 0–83.4 |
| % With worst possible score (floor) | 0.0 | 0.3 | 0.0 | 0.0 |
| %With best possible score (ceiling) | 41.2 | 43.5 | 59.5 | 21.1 |
| % With missing data# | 2.0 | 7.6 | 9.6 | 13.2 |
| % With missing score¶ | 1.2 | 1.2 | 1.2 | 1.2 |
| Cronbach's Alpha+ | ||||
| Probable case of COPD | 0.77 | 0.90 | 0.89 | 0.95 |
| Nonprobable case of COPD | 0.73 | 0.84 | 0.87 | 0.91 |
| Scale success rate %+ | ||||
| Probable case of COPD | 81.3 | 84.4 | 92.3 | 88.0 |
| Nonprobable case of COPD | 87.5 | 71.9 | 94.2 | 86.0 |
n=862
COPD: chronic obstructive pulmonary disease
sd: standard deviation
COPD: chronic obstructive pulmonary disease
#: percentage of individuals with at least one missing item
¶: percentage of individuals with missing score after handling missing data recommended by authors was applied
+: calculated separately for probable and nonprobable cases of COPD by using Multitrait Analysis Program because it is not possible to apply weights with this package