Table 1. General characteristics of the study subjects.
| Variables‡ | Subcategory | Total (n=4,134) N (%)† |
Young-old (65 to 79 years) (n=3,207) N (%)† |
Old-old (80 years or older) (n=927) N (%)† |
|---|---|---|---|---|
| Age*** | Mean ± SD | 74.5 ± 6.6 | 71.7 ± 4.1 | 84.2 ± 3.8 |
| Gender*** | Male | 1,754 (42.4) | 1,427 (44.5) | 327 (35.3) |
| Female | 2,380 (57.6) | 1,780 (55.5) | 600 (64.7) | |
| Life satisfaction score*** | Mean ± SD | 56.3 ± 18.3 | 57.5 ± 17.7 | 52.1 ± 19.6 |
| Depression*** | No | 1,857 (45.3) | 1,550 (48.8) | 307 (33.4) |
| Yes | 2,239 (54.7) | 1,627 (51.2) | 612 (66.6) | |
| Cognitive impairment*** | Fair | 2,225 (53.8) | 1,963 (61.2) | 262 (28.3) |
| Mild | 769 (18.6) | 583 (18.2) | 186 (20.1) | |
| Moderate or severe | 1,140 (27.6) | 661 (20.6) | 479 (51.7) | |
| K-ADL score*** | Mean ± SD | 0.4 ± 1.4 | 0.2 ± 1.1 | 0.9 ± 2.1 |
| Chronic diseases*** | No | 972 (23.5) | 795 (24.8) | 177 (19.1) |
| Yes | 3,162 (76.5) | 2,412 (75.2) | 750 (80.9) | |
| Level of education*** | Less than elementary school | 2,693 (65.1) | 1,933 (60.3) | 760 (82.0) |
| Middle school | 539 (13.0) | 474 (14.8) | 65 (7.0) | |
| High school | 635 (15.4) | 570 (17.8) | 65 (7.0) | |
| College or higher | 267 (6.5) | 230 (7.2) | 37 (4.0) | |
| Marital status*** | Widowed/divorced/single | 1,393 (33.7) | 834 (26.0) | 559 (60.3) |
| Married | 2,741 (66.3) | 2,373 (74.0) | 368 (39.7) | |
| Social activities*** | None | 1,349 (32.6) | 908 (28.3) | 441 (47.6) |
| 1 | 2,188 (52.9) | 1,782 (55.6) | 406 (43.8) | |
| 2 | 508 (12.3) | 436 (13.6) | 72 (7.8) | |
| 3+ | 89 (2.2) | 81 (2.5) | 8 (0.9) | |
| Familial communications*** | Mean ± SD | 84.9 ± 74.9 | 87.2 ± 74.9 | 76.8 ± 74.4 |
| Economic activities*** | No | 3,197 (77.3) | 2,337 (72.9) | 860 (92.8) |
| Yes | 937 (22.7) | 870 (27.1) | 67 (7.2) | |
| Household assets*** | 1st quartile (lowest) | 961 (23.9) | 679 (21.6) | 282 (31.7) |
| 2nd quartile | 978 (24.3) | 767 (24.5) | 211 (23.7) | |
| 3rd quartile | 1,071 (26.6) | 869 (27.7) | 202 (22.7) | |
| 4th quartile (highest) | 1,016 (25.2) | 822 (26.2) | 194 (21.8) | |
| Medical insurance*** | Medical aid | 330 (8.0) | 217 (6.8) | 113 (12.2) |
| NHI (Self-employed) | 928 (22.5) | 724 (22.6) | 204 (22.1) | |
| NHI (Workers) | 2,872 (69.5) | 2,264 (70.6) | 608 (65.7) |
Significance level: *p<0.05, **p<0.01, ***p<0.001. †Values are presented as n (%), unless otherwise indicated. ‡χ2 test or independent t-test were performed respectively, for discrete and continuous variables. K-ADL: Korean version of activities of daily living; NHI: National Health Insurance; SD: standard deviation