Table 2.
Reliability Alphas, Means and Standard Deviations for the QOL-D Instrument and its Subscales
| Cognitively intact | Cognitively impaired | ||||
|---|---|---|---|---|---|
| (self report) (N=132) | (caregiver report) | ||||
| Internal consistencya | |||||
| QOL-D scaleb | 0.62 | 0.78 (n=201)e | |||
| Activity subscalec | 0.60 | 0.76 (n=259) | |||
| Positive affect subscaled | 0.59 | 0.70 (n=229)e | |||
| Negative affect subscaled | 0.53 | 0.63 (n=231)e | |||
| Mean (SE) | Range | Mean (SE) | Range | n | |
| QOL-D scaleb *** | 36.5 (0.4) | 27-48 | 27.6 (0.3) | 13-49 | 259 |
| Activity subscalec,f*** | 11.7 (0.4) | 3-22 | 5.5 (0.3) | 0-26 | 259 |
| Positive Affect subscaled,f *** | 14.8 (0.5) | 12-15 | 13.6 (0.1) | 6-15 | 263 |
| Negative Affect * subscaled,f ** |
8.1 (0.2) |
6-14 |
9.4 (0.2) |
6-15 |
263 |
Notes: a. Cronbach’s alpha; b. Albert et al. 1996; c. Logsdon & Teri, 1997; Teri & Logsdon, 1991; d. Lawton, 1994; e. In order to calculate internal consistency, missing values for the positive and the negative affect subscales as well as the combined scale were left in; f. Higher scores for activity and positive affect and lower scores for negative affect indicate a better quality of life; *P < .05; ** P < .01; *** P < .001