Table 1.
Baseline Characteristics of Participants in a Random Sample of Population Aged 65 Years and Older
| Characteristics | ADL | IADL | ||||
| Nondisabled | Disabled | p value | Nondisabled | Disabled | p value | |
| N | 6,678 | 1,078 | 4,287 | 2,182 | ||
| Age (y) | 71.7 (5.8) | 78.9 (9.0) | <.001 | 72.5 (6.0) | 79.1 (8.3) | <.001 |
| Education (y) | 12.6 (3.4) | 10.8 (3.7) | <.001 | 13.1 (3.3) | 11.3 (3.5) | <.001 |
| Body mass index (kg/m2) | 28.1 (5.7) | 27.1 (7.6) | <.001 | 28.4 (5.5) | 27.7 (7.3) | <.001 |
| Cognitive function | 0.36 (.62) | −0.71 (1.1) | <.001 | 0.49 (.54) | −0.40 (1.1) | <.001 |
| Mini-Mental State Examination | 27.2 (3.1) | 22.3 (7.4) | <.001 | 27.7 (2.5) | 23.2 (6.7) | <.001 |
| Immediate recall | 8.9 (2.3) | 6.8 (3.4) | <.001 | 9.3 (2.1) | 7.3 (3.3) | <.001 |
| Delayed recall | 8.4 (2.7) | 6.0 (3.7) | <.001 | 8.9 (2.4) | 6.5 (3.8) | <.001 |
| Symbol digit test | 32.1 (13.1) | 18.0 (13.6) | <.001 | 34.4 (12.1) | 21.1 (13.1) | <.001 |
| Gender, % | <.001 | .003 | ||||
| Female | 60.6 | 73.7 | 62.2 | 66.0 | ||
| Male | 39.4 | 26.3 | 37.8 | 34.0 | ||
| Race, % | .01 | .02 | ||||
| Nonblacks | 36.4 | 32.9 | 35.3 | 32.2 | ||
| Blacks | 63.6 | 67.1 | 64.7 | 67.7 | ||
| Depressive symptoms, % | <.001 | <.001 | ||||
| 0–1 | 80.8 | 50.6 | 85.0 | 56.6 | ||
| 2–3 | 7.0 | 12.6 | 5.6 | 12.2 | ||
| 4+ | 12.2 | 36.8 | 9.2 | 31.1 | ||
| Chronic diseases, % | ||||||
| Heart disease | 11.4 | 23.2 | <.001 | 10.5 | 22.7 | <.001 |
| Diabetes mellitus | 6.3 | 13.5 | <.001 | 6.3 | 13.7 | <.001 |
| Stroke | 6.6 | 28.5 | <.001 | 6.6 | 23.2 | <.001 |
Notes: ADL = activities of daily living; IADL = instrumental activities of daily living.