Table 1

Descriptive characteristics of the prospective Chinese elderly cohort at baseline (1998–2001) by seasonal temperature variability

CharacteristicTotalSummertime temperature
variability*
Wintertime temperature
variability†
(Mean±SD: 1.4±0.2)(Mean±SD: 3.2±0.5)
LowHighLowHigh
(1.2±0.1)(1.6±0.1)(3.0±0.2)(3.4±0.1)
Participants, n61 44630 72330 72330 72230 724
Individual-level covariates
Age at entry, year,
n (%)
 ≤7029 038 (47.3)14 450 (47.0)14 588 (47.5)14 848 (48.3)14 190 (46.2)
 >7032 408 (52.7)16 273 (53.0)16 135 (52.5)15 874 (51.7)16 534 (53.8)
Sex, n (%)
 Male20 933 (34.1)10 384 (33.8)10 549 (34.3)10 930 (35.6)10 003 (32.6)
 Female40 513 (65.9)20 339 (66.2)20 174 (65.7)19 792 (64.4)20 721 (67.4)
BMI quartiles, n (%)
1st (<21.6)14 168 (23.1)7100 (23.1)7068 (23.0)7143 (23.3)7025 (22.9)
 2nd– 3rd (21.6–26.3)31 178 (50.7)15 574 (50.7)15 604 (50.8)15 616 (50.8)15 562 (50.7)
 4th (>26.3)16 100 (26.2)8049 (26.2)8051 (26.2)7963 (25.9)8137 (26.5)
Smoking status, n (%)
 Never43 668 (71.1)21 946 (71.4)21 722 (70.7)22 058 (71.8)21 610 (70.3)
 Former11 871 (19.3)5830 (19.0)6041 (19.7)5791 (18.8)6080 (19.8)
 Current5907 (9.6)2947 (9.6)2960 (9.6)2873 (9.4)3034 (9.9)
Exercise in days/week,
n (%)
 Never (0)9406 (15.3)4667 (15.2)4739 (15.4)4784 (15.6)4622 (15.0)
 Medium (1–6)7788 (12.7)3996 (13.0)3792 (12.3)4172 (13.6)3616 (11.8)
 High (7)44 252 (72.0)22 060 (71.8)22 192 (72.2)21 766 (70.8)22 486 (73.2)
Education attainment, 
n (%)
 Below primary28 241 (46.0)14 201 (46.2)14 040 (45.7)13 268 (43.2)14 973 (48.7)
 Primary22 656 (36.9)11 434 (37.2)11 222 (36.5)11 162 (36.3)11 494 (37.4)
 Secondary or above10 549 (17.2)5088 (16.6)5461 (17.8)6292 (20.5)4257 (13.9)
Housing type, n (%)
 Private32 458 (52.8)16 359 (53.2)16 099 (52.4)18 239 (59.4)14 219 (46.3)
 Public and aided25 096 (40.8)12 503 (40.7)12 593 (41.0)10 664 (34.7)14 432 (47.0)
 Other3892 (6.3)1861 (6.1)2031 (6.6)1819 (5.9)2073 (6.7)
Expenses/month in US$,
n (%)
 Low (<128)10 122 (16.5)5021 (16.3)5101 (16.6)5169 (16.8)4953 (16.1)
 Medium (128–384)42 151 (68.6)21 092 (68.7)21 059 (68.5)20 576 (67.0)21 575 (70.2)
 High (≥385)9173 (14.9)4610 (15.0)4563 (14.9)4977 (16.2)4196 (13.7)
Medication taken, n (%)
 Yes32 627 (53.1)16 397 (53.4)16 230 (52.8)16 430 (53.5)16 197 (52.7)
 No28 819 (46.9)14 326 (46.6)14 493 (47.2)14 292 (46.5)14 527 (47.3)
TPU-level covariate
 SDI (mean±SD)13.8 (2.0)13.9 (2.1)13.8 (2.0)14.0 (2.3)13.7 (1.8)
 District-level covariate
 Smoking rate (mean±SD)11.6 (0.4)11.6 (0.3)11.5 (0.4)11.6 (0.3)11.5 (0.4)
  • *High and low summertime temperature variability was defined by the median (1.4°C) of the SD of daily mean summer temperature.

  • †High and low wintertime temperature variability was defined by the median (3.2°C) of the SD of daily mean winter temperature.

  • BMI, body mass index; SDI, social deprivation index; TPUs, tertiary planning units.