Table 2
Baseline characteristics of participants in the Shenzhen ageing-related disorder cohort
| Variables | Total (n=9411) | Male (n=4022) | Female (n=5389) | t/ * | P value |
| Age (years, mean±SD) | 67.73±5.41 | 68.38±5.59 | 67.24±5.23 | 10.12 | <0.0001 |
| Age groups (years, n, %) | 89.80 | <0.0001 | |||
| 60–64 | 3142 (33.39) | 1167 (29.02) | 1975 (36.65) | ||
| 65–69 | 3274 (34.79) | 1399 (34.78) | 1875 (34.79) | ||
| 70–74 | 1818 (19.32) | 848 (21.08) | 970 (18.00) | ||
| ≥75 | 1177 (12.51) | 608 (15.12) | 569 (10.56) | ||
| Race (n, %) | 6.88 | 0.03 | |||
| Han Chinese | 8577 (91.14) | 3684 (91.60) | 4893 (90.80) | ||
| Other ethnic groups | 57 (0.61) | 15 (0.37) | 42 (0.78) | ||
| Missing | 777 (8.26) | 323 (8.03) | 454 (8.42) | ||
| Migration time to Shenzhen (n, %) | 65.89 | <0.0001 | |||
| <1950 | 1450 (15.41) | 554 (13.77) | 896 (16.63) | ||
| 1950- | 404 (4.29) | 174 (4.33) | 230 (4.27) | ||
| 1970- | 3735 (39.69) | 1722 (42.81) | 2013 (37.35) | ||
| 1990- | 2661 (28.28) | 1022 (25.41) | 1639 (30.41) | ||
| 2010- | 729 (7.75) | 365 (9.08) | 364 (6.75) | ||
| Missing | 432 (4.59) | 185 (4.60) | 247 (4.58) | ||
| Education level (n, %) | 571.31 | <0.0001 | |||
| Primary school or illiteracy | 1637 (17.39) | 390 (9.70) | 1247 (23.14) | ||
| Middle school | 2564 (27.24) | 934 (23.22) | 1630 (30.25) | ||
| High school | 3143 (33.40) | 1450 (36.05) | 1693 (31.42) | ||
| University or college or higher | 1977 (21.01) | 1210 (30.08) | 767 (14.23) | ||
| Missing | 90 (0.96) | 38 (0.94) | 52 (0.96) | ||
| Marital status (n, %) | 419.31 | <0.0001 | |||
| Single | 37 (0.39) | 13 (0.32) | 24 (0.45) | ||
| Married | 8045 (85.49) | 3762 (93.54) | 4283 (79.48) | ||
| Widowed | 1023 (10.87) | 147 (3.65) | 876 (16.26) | ||
| Divorced | 119 (1.26) | 26 (0.65) | 93 (1.73) | ||
| Cohabited | 2 (0.02) | 0 | 2 (0.04) | ||
| Remarried | 9 (0.10) | 7 (0.17) | 2 (0.04) | ||
| Missing | 176 (1.87) | 67 (1.67) | 109 (2.02) | ||
| Family yearly income (yuan, n, %) | 32.87 | <0.0001 | |||
| <40 000 | 306 (3.25) | 87 (2.16) | 219 (4.06) | ||
| 40 000 - | 857 (9.11) | 339 (8.43) | 518 (9.61) | ||
| 80 000 - | 1401 (14.89) | 626 (15.56) | 775 (14.38) | ||
| 120 000 - | 1951 (20.73) | 852 (21.18) | 1099 (20.39) | ||
| ≥160 000 | 4114 (43.71) | 1787 (44.43) | 2327 (43.18) | ||
| Missing | 782 (8.31) | 331 (8.23) | 451 (8.37) | ||
| Exposure to occupational hazards† | 127.85 | <0.0001 | |||
| Yes | 1563 (16.61) | 834 (20.74) | 729 (13.53) | ||
| No | 5361 (56.97) | 2309 (57.41) | 3052 (56.63) | ||
| Missing | 2487 (26.43) | 879 (21.85) | 1608 (29.84) | ||
| Exposure to kitchen fumes (n, %) | 1104.43 | <0.0001 | |||
| Yes | 6284 (66.77) | 1943 (48.31) | 4341 (80.55) | ||
| No | 2975 (31.61) | 2017 (50.15) | 958 (17.78) | ||
| Missing | 152 (1.62) | 62 (1.54) | 90 (1.67) | ||
| Menolipsis (n=5233, %) | – | 5230 (99.94) | |||
| Parturition (n=5233, times) | – | 2.02±1.04 |
*Student’s t-test and Pearson
test were used for the comparisons between continuous variables and categorical variables, respectively.†Occupational hazards included high temperature, noise, radiation, metal, dust, organic solvent and farm chemical.