Table 1.
Descriptive Statistics
| Year | 1998 | 2003 | 2005 | 2008 |
|---|---|---|---|---|
| Sample size | 2,763 | 3,222 | 1,680 | 2,195 |
| Mean age (SD) | 72.9 (6.2) | 73.9 (6.4) | 74.4 (6.5) | 75.1 (6.5) |
| Women (%) | 55.5 | 54.4 | 54.9 | 54.3 |
| Rural residence (%) | 31.5 | 31.5 | 21.5 | 9.2 |
| Good economic status (%) | 75.2 | 76.4 | 76.1 | 87.0 |
| 0 year of schooling (%) | 48.2 | 39.3 | 33.2 | 28.7 |
| 1–9 years of schooling (%) | 39.0 | 42.2 | 46.8 | 50.3 |
| 10+ years of schooling (%) | 12.8 | 18.5 | 20.0 | 21.0 |
| Married (%) | 58.8 | 61.9 | 61.7 | 67.9 |
| Satisfaction with children’s support (%) | 56.5 | 58.8 | 55.8 | 38.1 |
| Public medical service (%) | 61.6 | 64.6 | 64.2 | 75.3 |
| Mean comorbidity (range: 0–8) (SD) | 1.3 (1.2) | 1.6 (1.3) | 1.6 (1.2) | 1.5 (1.2) |
| Mean unhealthy symptom (range: 0–10) (SD) | 2.0 (2.0) | 1.8 (2.0) | 1.8 (1.6) | 1.5 (1.5) |
| Mean depressive symptom (range: 0–21) (SD) | 4.2 (3.7) | 4.4 (3.5) | 3.6 (3.8) | 3.9 (3.6) |
| Mean cognitive impairment (range: 0–10) (SD) | 1.2 (1.9) | 0.8 (1.7) | 0.6 (1.4) | 0.6 (1.4) |
| Any ADL limitation (%) | 15.9 | 16.9 | 15.5 | 14.9 |
| Any IADL limitation (%) | 42.1 | 39.7 | 37.6 | 30.1 |
Note. ADL = activities of daily living; IADL = instrumental activities of daily living; SD = standard deviation.