Table 3.
Mean QOL Scores for Different Severity Levels of the Core Symptoms Variables
| N† (%) | EQ-5D (n=368) Mean SD |
QWB (n=369) Mean SD |
VAS (n=362) Mean SD |
QOL-AD (n=367) Mean SD |
|
|---|---|---|---|---|---|
|
|
|
|
|||
| ADAS (Cognition) | |||||
| 8–21 | 111 (30.0) | 0.89 (0.12) | 0.63 (0.15) | 0.78 (0.14) | 40.6 (5.6) |
| 22–25 | 89 (24.1) | 0.87 (0.13) | 0.61 (0.15) | 0.77 (0.15) | 39.1 (5.3) |
| 26–34 | 108 (29.2) | 0.92 (0.11) | 0.65 (0.16) | 0.77 (0.14) | 40.3 (5.1) |
| 35–70 | 62 (16.8) | 0.87 (0.16) | 0.65 (0.18) | 0.71 (0.17) | 38.6 (5.3) |
| DAD (Function) | |||||
| 0–49 | 69 (18.6) | 0.90 (0.14) | 0.67 (0.18) | 0.75 (0.16) | 39.5 (5.1) |
| 50–68 | 92 (24.9) | 0.90 (0.14) | 0.64 (0.17) | 0.75 (0.17) | 38.7 (5.3) |
| 69–88 | 109 (29.5) | 0.88 (0.12) | 0.62 (0.15) | 0.77 (0.13) | 39.9 (4.8) |
| 89–100 | 100 (27.0) | 0.89(0.13) | 0.62(0.13) | 0.77(0.14) | 41.0(6.1) |
| NPI (Behavior) | |||||
| 0 | 59 (15.9) | 0.92 (0.11) | 0.69 (0.16) | 0.81 (0.12) | 42.1 (4.9) |
| 1–6 | 120 (32.4) | 0.91 (0.12) | 0.64 (0.15) | 0.77 (0.14) | 40.3 (5.5) |
| 7–14 | 98 (26.5) | 0.87 (0.13) | 0.63 (0.16) | 0.73 (0.16) | 39.2 (5.2) |
| 15–73 | 93 (25.1) | 0.87 (0.14) | 0.61 (0.15) | 0.76 (0.15) | 38.5 (5.3)* |
| GDS (Depression) | |||||
| 0–4 | 175 (47.3) | 0.94 (0.09) | 0.69 (0.15) | 0.81 (0.13) | 42.1 (4.6) |
| 5–10 | 145 (39.2) | 0.88 (0.12) | 0.60 (0.14) | 0.74 (0.14) | 38.9 (4.6) |
| 11–13 | 28 (7.6) | 0.80 (0.14) | 0.55 (0.14) | 0.69 (0.15) | 35.5 (5.4) |
| 14–30 | 22 (5.9) | 0.70 (0.21)** | 0.48 (0.12)** | 0.68 (0.19)** | 33.2 (5.9)** |
EQ-5D = European Quality of Life-5 Dimensions; QWB = Quality of Well-Being Index; VAS = global quality of life Visual Analog Scale; QOL-AD = Quality of Life-Alzheimer’s Disease; ADAS = Alzheimer’s Disease Assessment Scale-Cognitive sub-scale; DAD = Disability Assessment for Dementia; NPI = Neuropsychiatric Inventory; GDS = Geriatric Depression Scale.
The EQ-5D, QWB and VAS are rated on 0–1 scales; The QOL-AD is rated on a 13–52 scale.
p<0.001;
p<0.0001;
the p-values comparing the mean quality of life scores across the levels of the symptom severity scores were derived from the overall F-test in a one-way analysis of variance. All tests had numerator degrees of freedom (df) of 3 and denominator df of 365, 366, 359 and 364 for the EQ-5D, QWB, VAS and QOL-AD, respectively.
N = the number of participants from the full analytic cohort (n=370) in each severity level for each of the core dementia symptom measures. Because not all cohort participants completed each quality of life measure, the number of participants in each core symptom severity level varied slightly among the quality of life measures compared with the total cohort. These differences were 2 or less participants per severity level except for the following core symptom severity levels for the VAS: ADAS 35–70 (n=57, 15.7%), DAD 0–49 (n=64, 17.7%), NPI 0 (n=56, 15.5%), NPI 15–73 (n=90, 24.9%), GDS 0–4 (n=171, 47.2%), and GDS 5–10 (n=142, 39.2%).