Table 1 Baseline characteristics of the total sample and the sample by the different trajectory groups
Variable | Total | Groups | ||
|---|---|---|---|---|
Increase (N = 414) | Late increase (N = 2023) | Relatively stable (N = 391) | ||
Socio-demographic variablesa | ||||
 Age, M (SD) | 71.65 (4.72) | 72.17 (4.96) | 71.63 (4.70) | 71.24 (4.55) |
 Gender, (n, %) | ||||
  Male | 1380 (48.8) | 141 (34.1) | 1026 (50.7) | 213 (54.5) |
  Female | 1448 (51.2) | 273 (65.9) | 997 (49.3) | 178 (45.5) |
 Education, (n, %) | ||||
  No education | 557 (19.7) | 122 (29.5) | 383 (18.9) | 52 (13.3) |
  Some primary school | 913 (32.3) | 132 (31.9) | 681 (33.7) | 100 (25.6) |
  Primary school | 495 (17.5) | 68 (16.4) | 347 (17.2) | 80 (20.5) |
  Secondary / Matriculation | 558 (19.7) | 63 (15.2) | 399 (19.7) | 96 (24.6) |
  University or above | 305 (10.8) | 29 (7.0) | 213 (10.5) | 63 (16.1) |
 Marriage statues, (n, %) | ||||
  Married or living in a married-like relationship | 2063 (72.9) | 269 (65.0) | 1489 (73.6) | 305 (78.0) |
  Windowed | 646 (22.8) | 121 (29.2) | 447 (22.1) | 78 (19.9) |
  Separated | 44 (1.6) | 7 (1.7) | 35 (1.7) | 2 (0.5) |
  Divorced | 25 (0.9) | 6 (1.4) | 17 (0.8) | 2 (0.5) |
  Single, never married | 50 (1.8) | 11 (2.7) | 35 (1.7) | 4 (1.0) |
 The quality of life | ||||
  Physical Component, M (SD) | 49.19 (8.05) | 45.91 (9.33) | 49.22 (7.85) | 52.48 (5.98) |
  Mental Component, M (SD) | 56.09 (6.48) | 51.51 (8.86) | 56.67 (5.84) | 57.99 (4.15) |
Health-related information | ||||
 BMI, M (SD) | 23.79 (3.18) | 23.93 (3.25) | 23.79 (3.22) | 23.65 (2.91) |
 Self-reported health status, (n, %) | ||||
  Poor/ very poor/ fair | 2662 (94.1) | 357 (86.2) | 1920 (94.9) | 385 (98.5) |
  Good / excellent | 162 (5.7) | 57 (13.8) | 103 (5.1) | 6 (1.5) |
 The number of chronic diseases, M (SD) | 1.54 (1.28) | 1.80 (1.33) | 1.54 (1.29) | 1.28 (1.07) |
 PASE, M (SD) | 94.31 (43.45) | 88.63 (39.74) | 94.73 (43.89) | 98.14 (44.43) |
 Smoke, (n, %) | ||||
  No smoke | 2666 (94.3) | 395 (95.4) | 1897 (93.8) | 374 (95.7) |
  Current smoker | 162 (5.7) | 19 (4.6) | 126 (6.2) | 17 (4.3) |
 Drink, (n, %) | ||||
  No | 2446 (86.5) | 382 (92.3) | 1742 (86.1) | 323 (82.6) |
  Yes | 381 (13.5) | 32 (7.7) | 281 (13.9) | 68 (17.4) |
 Depression symptom, M (SD) | 2.47 (2.24) | 5.21 (2.42) | 2.34 (1.79) | 0.22 (0.57) |
 Cognitive function, M (SD) | 25.98 (3.39) | 24.72 (3.92) | 26.03 (3.32) | 27.04 (2.64) |
Air quality variablesb | ||||
 The concentration of PM10, M (SD) | 52.00 (2.89) | 52.05 (2.91) | 51.99 (2.87) | 51.98 (2.94) |
 The concentration of NO2, M (SD) | 62.95 (12.98) | 62.93 (12.22) | 62.78 (13.03) | 63.83 (13.50) |