Description of the three groups of elderly subjects detected by cluster analysis
| Variable | Group 1 | Group 2 | Group 3 | p Value† |
|---|---|---|---|---|
| Age (years) | 68.05 (5.67) | 71.72 (7.05) | 77.17 (6.98) | 0.000 |
| MMSE score | 27.85 (2.11) | 27.47 (2.04) | 26.96 (2.63)* | 0.000 |
| CESD score | 4.84 (4.80) | 5.93 (6.34) | 6.77 (6.54) | 0.007 |
| Four dimensions of CESD | ||||
| Dimension 1 (depressed affect) | 0.7 (1.44) | 1.12 (2.19) | 1.39 (2.59) | 0.005 |
| Dimension 2 (positive affect) | 1.73 (2.31) | 2.25 (2.63) | 2.62 (2.89) | 0.003 |
| Dimension 3 (somatic and retarded activity) | 2.10 (2.23) | 2.28 (2.56) | 2.52 (2.58) | 0.243 |
| Dimension 4 (interpersonal) | 0.21 (0.55) | 0.28 (0.66) | 0.20 (0.55) | 0.171 |
| Cortical atrophy | 4.52 (2.50) | 5.30 (2.65) | 7.14 (3.07) | 0.000 |
| Subcortical atrophy | 0.30 (0.02) | 0.31 (0.36) | 0.32 (0.03) | 0.000 |
| White matter lesions | ||||
| Frontal | 0.09 (0.02) | 0.25 (0.45) | 3.06 (3.01) | 0.000 |
| Parietal | 0.04 (0.05) | 0.18 (0.20) | 1.97 (1.64) | 0.000 |
| Temporal | 0 (0.0) | 0.007 (0.07) | 0.04 (0.19) | 0.000 |
| Occipital | 0 (0.0) | 0.05 (0.03) | 0.17 (0.51) | 0.000 |
| Periventricular | 0.34 (0.73) | 1.98 (1.51) | 5.39 (1.80) | 0.000 |
| Per cent distribution | p Value‡ | |||
|---|---|---|---|---|
| Values are mean (SD), top, or % (n), bottom. | ||||
| *Group 3 significantly different from groups 1 and 2. | ||||
| †Variance analysis or Kruskal–Wallis test as appropriate. | ||||
| ‡χ2 test. | ||||
| CESD, Center of Epidemiologic Studies depression scale; CVA, cerebrovascular accident; MMSE, mini-mental state examination. | ||||
| Female sex | 48.4 (93) | 50.8 (334) | 57.2 (127) | 0.154 |
| Education <8 years | 12.6 (24) | 11.9 (78) | 9.5 (21) | 0.558 |
| Late onset depressive persons | 3.9 (6) | 8.5 (46) | 11.1 (22) | 0.05 |
| Positive CESD (score >16) | 2.6 (5) | 7.7 (50) | 11.0 (24) | 0.05 |
| CVA | 0.5 (1) | 4.2 (27) | 12.6 (27) | 0.000 |
| Cerebrovascular risk factors | ||||
| Hypertension or use of antihypertensive drugs | 40.6 (78) | 49.2 (324) | 67.1 (149) | 0.000 |
| Diabetes mellitus | 3.1 (6) | 7.6 (50) | 8.6 (19) | 0.06 |
| Current smoker | 16.7 (32) | 18.2 (120) | 13.6 (30) | 0.288 |