Table 2.
Descriptive statistics of the potentially confounding variables
| Confounding variables | Number | Percent |
|---|---|---|
| Socio-demographic characteristics | ||
| Mean age | 86.40 | --- |
| Gender | ||
| Male | 5,896 | 42.72 |
| Female | 7,904 | 57.28 |
| Race | ||
| Han | 12,956 | 93.88 |
| Minority | 844 | 6.12 |
| Current residence | ||
| Urban | 5,941 | 43.05 |
| Rural | 7,859 | 56.95 |
| Education | ||
| Literate | 8,637 | 62.59 |
| Illiterate | 5,163 | 37.41 |
| Primary occupation before age 60 | ||
| Non-manual job | 1,110 | 8.04 |
| Manual job | 12,690 | 91.96 |
| Marital status | ||
| Currently married | 4,081 | 29.57 |
| Currently not-married | 9,719 | 70.43 |
| Initial health status | ||
| Activities of daily living | ||
| Independent | 9,697 | 70.27 |
| Dependent | 4,103 | 29.73 |
| MMSE | ||
| Good | 8,160 | 59.13 |
| Impaired | 5,640 | 40.87 |
Note: Variables are measured at the 2002 interview.