Psychometric Properties of the ABCC Scale for People with COPD (n = 65)
| Convergent validity, SGRQ, r | ||||
|---|---|---|---|---|
| ABCC domains | Total | Activity | Impact | Symptoms |
| ABCC total | 0.866a | 0.797a | 0.806a | 0.734a |
| Physical limitation | 0.829a | 0.831a | 0.743a | 0.668 |
| Pulmonary complaints | 0.761a | 0.636 | 0.697 | 0.773a |
| Known group validity, median (IQR) | |||
|---|---|---|---|
| <2 Exacerbations E (n = 33) | ≥2 Exacerbations (n = 32) | P value | |
| ABCC total | 1.6 (0.9-2.6) | 2.6 (2.4-3.6) | <.001 |
| Night’s rest | 2.0 (0.5-2.5) | 2.5 (2.0-3.0) | .006 |
| Feelings and emotions | 1.0 (0.3-2.0) | 2.0 (1.0-2.7) | .010 |
| Physical limitations | 2.3 (1.0-4.2) | 3.7 (3.0-4.9) | .003 |
| Relations and work | 1.0 (0.5-3.0) | 3.0 (2.0-4.0) | <.001 |
| Pulmonary complaints | 2.3 (1.6-3.0) | 3.3 (2.6-3.9) | <.001 |
| Not depressedb (n = 50) | Depressedb (n = 15) | P value | |
| ABCC total | 2.1 (1.2-2.9) | 3.1 (2.5-3.9) | .001 |
| Fatigue | 3.0 (2.0-4.0) | 4.0 (3.0-5.0) | .022 |
| Feelings and emotions | 1.0 (0.3-2.0) | 2.0 (1.7-2.7) | .001 |
| Physical limitations | 3.0 (1.3-4.3) | 3.7 (3.0-4.7) | .057 |
| Relations and work | 2.0 (1.0-3.0) | 3.0 (3.0-4.0) | .002 |
| Pulmonary complaints | 2.6 (1.8-3.5) | 3.0 (2.5-4.0) | .061 |
| Reliability measures | |
|---|---|
| Internal consistency, Cronbach’s α (95% CI) | |
| Total scale | 0.90 (0.86-0.93) |
| Physical limitations | 0.92 (0.88-0.95) |
| Feelings and emotions | 0.77 (0.64-0.85) |
| Pulmonary complaints | 0.65 (0.49-0.77) |
| Test-retest reliability, ICC (95% CI) (n = 60) | |
| 0.95 (0.92-0.97) | |
ABCC = Assessment of Burden of Chronic Conditions; COPD = chronic obstructive pulmonary disease; ICC = intraclass coefficient; IQR = interquartile range; HADS = Hospital Anxiety and Depression Scale; r = Pearson correlation coefficient; SGRQ = Saint George Respiratory Questionnaire.
↵a r >0.7.
↵b Depression determined with HADS score, <8 not depressed, ≥8 depressed.