Table 1.
Basic characteristics of the study population by survey year
| Characteristics | 2011(n=8187) | 2021(n=7572) |
| Sex | ||
| Male | 3960 (48.4) | 3739 (49.4) |
| Female | 4227 (51.6) | 3833 (50.6) |
| Ethnicity | ||
| Han | 5008 (61.2) | 4124 (54.5)* |
| Naxi | 1998 (24.4) | 2531 (33.4) |
| Buyi | 542 (6.6) | 747 (9.9) |
| ther | 639 (7.8) | 170 (2.2) |
| Age | ||
| 35–44 years | 1851 (22.6) | 1256 (16.6)* |
| 45–54 years | 2119 (25.9) | 1905 (25.2) |
| 55–64 years | 2014 (24.6) | 1856 (24.5) |
| 65–74 years | 1403 (17.1) | 1670 (22.1) |
| ≥75 years | 800 (9.8) | 885 (11.7) |
| Level of education | ||
| Illiterate | 2495 (30.5) | 1730 (22.8)* |
| Primary (grade 1–6) or higher | 5692 (69.5) | 5842 (77.2) |
| Annual household income per capita (US$) | ||
| ≤1083 | 4196 (51.3) | 3844 (50.8) |
| >1083 | 3991 (48.7) | 3728 (49.2) |
| Accessibility to medical services (min) | ||
| ≥30 | 3645 (44.5) | 2434 (32.1)* |
| <30 | 4542 (55.5) | 5138 (67.9) |
| SEP | ||
| Low | 2175 (26.6) | 1863 (24.6) |
| Lower middle | 1104 (13.5) | 1815 (24.0) |
| Upper middle | 3028 (37.0) | 2026 (26.8) |
| High | 1880 (23.0) | 1868 (24.7)* |
*P<0.01.