Table 1.
Comparison of demographic characteristics between the excluded and included subjects in CHNS 1991–2015.
| Characteristic | 1991–2015 combined | 1991 | 1993 | 1997 | 2000 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Excluded | Included | p | Excluded | Included | P | Excluded | Included | p | Excluded | Included | p | Excluded | Included | P | |
| 3,460 | 15,143 | value | 508 | 2,429 | value | 527 | 2,254 | value | 622 | 2,254 | value | 660 | 2,217 | value | |
| AGE GROUP | |||||||||||||||
| 7–12 years | 1,526 (44.10%) | 8,783 (58.00%) | <0.001 | 229 (45.08%) | 1,335 (54.96%) | <0.001 | 246 (46.68%) | 1,285 (57.01%) | <0.001 | 271 (43.57%) | 1,358 (60.25%) | <0.001 | 207 (31.36%) | 1,207 (54.44%) | <0.001 |
| 13–17 years | 1,934 (55.90%) | 6,360 (42.00%) | 279 (54.92%) | 1,094 (45.04%) | 281 (53.32%) | 969 (42.99%) | 351 (56.43%) | 896 (39.75%) | 453 (68.64%) | 1,010 (45.56%) | |||||
| SEX | |||||||||||||||
| Male | 1,842 (53.24%) | 7,947 (52.48%) | 0.421 | 277 (54.53%) | 1,251 (51.50%) | 0.215 | 256 (48.58%) | 1,175 (52.13%) | 0.142 | 333 (53.54%) | 1,192 (52.88%) | 0.773 | 342 (51.82%) | 1,176 (53.04%) | 0.58 |
| Female | 1,618 (46.76%) | 7,196 (47.52%) | 231 (45.47%) | 1,178 (48.50%) | 271 (51.42%) | 1,079 (47.87%) | 289 (46.46%) | 1,062 (47.12%) | 318 (48.18%) | 1,041 (46.96%) | |||||
| LOCATION | |||||||||||||||
| Urban | 866 (25.03%) | 4,347 (28.71%) | <0.001 | 112 (22.05%) | 620 (25.52%) | 0.099 | 110 (20.87%) | 566 (25.11%) | 0.041 | 142 (23.00%) | 659 (29.24%) | 0.002 | 161 (24.39%) | 609 (27.47%) | 0.117 |
| Rural | 2,594 (74.97%) | 10,796 (71.29%) | 396 (77.95%) | 1,809 (74.48%) | 417 (79.13%) | 1,688 (74.89%) | 480 (77.00%) | 1,595 (70.76%) | 499 (75.61%) | 1,608 (72.53%) | |||||
| REGION | |||||||||||||||
| North | 1,434 (41.45%) | 5,286 (34.91%) | <0.001 | 226 (44.49%) | 728 (29.97%) | <0.001 | 228 (43.26%) | 698 (30.97%) | <0.001 | 221 (35.53%) | 776 (34.43%) | 0.609 | 266 (40.3%) | 964 (43.48%) | 0.147 |
| South | 2,026 (58.55%) | 9,857 (65.09%) | 282 (55.51%) | 1,701 (70.03%) | 299 (56.74%) | 1556 (69.03%) | 401 (64.47%) | 1,478 (65.57%) | 394 (59.70%) | 1,253 (56.52%) | |||||
| BMI (kg/m2) | 17.42 ± 4.63 | 17.69 ± 3.25 | 0.040 | 15.4 ± 1.86 | 17.38 ± 2.78 | <0.001 | 15.66 ± 1.94 | 17.28 ± 2.68 | <0.001 | 15.66 ± 2.05 | 17.43 ± 2.78 | <0.001 | 16.46 ± 2.41 | 17.68 ± 2.85 | 0.004 |
| WC (cm) | 59.01 ± 12.85 | 62.87 ± 9.9 | <0.001 | NA | NA | 56.48 ± 6.8 | 62.39 ± 8.5 | <0.001 | 55.98 ± 6.45 | 61.39 ± 8.17 | <0.001 | 58.42 ± 7.12 | 62.8 ± 8.38 | <0.001 | |
| GENERAL OBESITY | |||||||||||||||
| Normal | 568 (85.80%) | 13,228 (88.06%) | 0.08 | 83 (94.32%) | 2,222 (92.20%) | 0.47 | 86 (93.48%) | 2,046 (91.96%) | 0.60 | 101 (93.52%) | 2,042 (91.12%) | 44 (95.65%) | 1,983 (90.05%) | 0.21 | |
| Overweight/ Obesity | 94 (14.20%) | 1,794 (11.94%) | 5 (5.68%) | 188 (7.80%) | 6 (6.52%) | 179 (8.04%) | 7 (6.48%) | 199 (8.88%) | 0.39 | 2 (4.35%) | 219 (9.95%) | ||||
| CENTRAL OBESITY | |||||||||||||||
| Normal | 567 (91.60%) | 10,571 (91.68%) | 0.94 | NA | NA | 66 (95.65%) | 1,217 (96.36%) | 0.76 | 128 (96.24%) | 2,078 (96.25%) | 1.00 | 72 (94.74%) | 2,068 (94.65%) | 0.97 | |
| Central Obesity | 52 (8.40%) | 959 (8.32%) | NA | NA | 3 (4.35%) | 46 (3.64%) | 5 (3.76%) | 81 (3.75%) | 4 (5.26%) | 117 (5.35%) | |||||
| AGE GROUP | |||||||||||||||
| 7–12 years | 158 (55.83%) | 646 (47.36%) | 0.009 | 74 (48.37%) | 667 (58.25%) | 0.02 | 63 (49.61%) | 618 (61.07%) | 0.013 | 42 (52.5%) | 874 (62.25%) | 0.081 | 236 (47.2%) | 793 (74.53%) | <0.001 |
| 13–17 years | 125 (44.17%) | 718 (52.64%) | 79 (51.63%) | 478 (41.75%) | 64 (50.39%) | 394 (38.93%) | 38 (47.5%) | 530 (37.75%) | 264 (52.8%) | 271 (25.47%) | |||||
| Sex | |||||||||||||||
| Male | 154 (54.42%) | 720 (52.79%) | 0.617 | 85 (55.56%) | 609 (53.19%) | 0.581 | 72 (56.69%) | 562 (55.53%) | 0.804 | 41 (51.52%) | 713 (50.78%) | 0.935 | 282 (56.4%) | 549 (51.60%) | 0.047 |
| Female | 129 (45.58%) | 644 (47.21%) | 68 (44.44%) | 536 (46.81%) | 55 (43.31%) | 450 (44.47%) | 39 (48.75%) | 691 (49.22%) | 218 (43.6%) | 515 (48.40%) | |||||
| LOCATION | |||||||||||||||
| Urban | 59 (20.85%) | 408 (29.91%) | 0.002 | 41 (26.80%) | 343 (29.96%) | 0.421 | 35 (27.56%) | 274 (27.08%) | 0.908 | 34 (42.50%) | 530 (37.75%) | 0.395 | 172 (34.40%) | 338 (31.77%) | 0.3 |
| Rural | 224 (79.15%) | 956 (70.09%) | 112 (73.20%) | 802 (70.04%) | 92 (72.44%) | 738 (72.92%) | 46 (57.50%) | 874 (62.25%) | 328 (66.00%) | 726 (68.23%) | |||||
| REGION | |||||||||||||||
| North | 138 (48.76%) | 556 (40.76%) | 0.013 | 77 (50.33%) | 445 (38.86%) | 0.007 | 40 (31.50%) | 375 (37.06%) | 0.22 | 35 (43.75%) | 442 (31.48%) | 0.022 | 203 (40.60%) | 302 (28.38%) | <0.001 |
| South | 145 (51.24%) | 808 (59.24%) | 76 (49.67%) | 700 (61.14%) | 87 (68.50%) | 637 (62.94%) | 45 (56.25%) | 962 (68.52%) | 297 (59.40%) | 762 (71.62%) | |||||
| BMI, kg/m2 | 16.54 ± 2.71 | 18.1 ± 2.92 | <0.001 | 16.65 ± 2.93 | 17.77 ± 3.09 | 0.109 | 16.96 ± 4.28 | 17.79 ± 3.35 | 0.4368 | 15.57 ± 2.14 | 18.35 ± 3.8 | 0.0208 | 21.12 ± 6.52 | 18.28 ± 5.6 | <0.001 |
| WC, cm | 57.73 ± 8.53 | 64.1 ± 9.47 | <0.001 | 57.55 ± 7.63 | 62.52 ± 10.01 | 0.005 | 67.49 ± 7.36 | 63.07 ± 10.01 | 0.1273 | 55.57 ± 7.21 | 64.49 ± 11.96 | 0.0683 | 63.11 ± 20.26 | 63.03 ± 13.71 | 0.9487 |
| GENERAL OBESITY | |||||||||||||||
| Normal | 87 (87.88%) | 1,181 (87.35%) | 0.88 | 14 (70.00%) | 979 (87.49%) | 0.02 | 9 (90.00%) | 845 (83.83%) | 0.60 | 10 (100.00%) | 1,111 (79.13%) | 0.11 | 134 (70.90%) | 819 (77.19%) | 0.06 |
| Overweight/ Obesity | 12 (12.12%) | 171 (12.65%) | 6 (30.00%) | 140 (12.51%) | 1 (10.00%) | 163 (16.17%) | 0 (0.00%) | 293 (20.87%) | 55 (29.10%) | 242 (22.81%) | |||||
| CENTRAL OBESITY | |||||||||||||||
| Normal | 105 (94.59%) | 1,243 (92.21%) | 0.36 | 33 (100.00%) | 1,047 (93.32%) | 0.13 | 10 (83.33%) | 898 (89.62%) | 0.48 | 6 (100.00%) | 1,168 (83.31%) | 0.27 | 147 (82.12%) | 852 (81.22%) | 0.77 |
| Central Obesity | 6 (5.41%) | 105 (7.79%) | 0 (0.00%) | 75 (6.68%) | 2 (16.67%) | 104 (10.38%) | 0 (0.00%) | 234 (16.69%) | 32 (17.88%) | 197 (18.78%) | |||||
Data are presented as means ± standard deviations or n (%); BMI, Body Mass Index; WC, Waist Circumference.