Table 1 Characteristics of Korean adults aged ≥19 years participating in KNHANES V (2010–2012) (N = 17,638)
| Â | Sleep duration | Â | ||
|---|---|---|---|---|
Variable | ≤6 h | 7–8 h | ≥9 h | p-valueb |
|  | n = 7,384 | n = 8,936 | n = 1,318 |  |
Age (mean ± SD)a | 47.9 ± 16.0 | 44.1 ± 15.0 | 44.7 ± 18.2 | <.001 |
Sex | Â | Â | Â | |
 Male | 3110 (41.6) | 3861 (51.6) | 511 (6.8) | 0.001 |
 Female | 4274 (42.1) | 5075 (50.0) | 807 (8.0) |  |
Household income | Â | Â | Â | |
 Low | 1789 (42.2) | 2054 (48.4) | 397 (9.4) | <.001 |
 Middle-low | 1781 (40.3) | 2270 (51.4) | 364 (8.2) |  |
 Mid-upper | 1841 (41.6) | 2282 (51.6) | 301 (6.8) |  |
 High | 1889 (43.2) | 2242 (51.3) | 242 (5.5) |  |
Education | Â | Â | Â | |
 ≤8 years | 2316 (50.6) | 1816 (39.6) | 449 (9.8) | <.001 |
 9–11 years | 833 (43.1) | 953 (49.3) | 148 (7.7) |  |
 12–15 years | 2209 (38.5) | 3119 (54.3) | 413 (7.2) |  |
 ≥16 years | 2006 (37.6) | 3028 (56.7) | 304 (5.7) |  |
Employment | Â | Â | Â | |
 Unemployed | 3011 (41.9) | 3499 (48.7) | 680 (9.5) | <.001 |
 Employed | 4355 (41.9) | 5418 (52.1) | 634 (6.1) |  |
Marital status | Â | Â | Â | |
 With spouse | 5330 (40.6) | 6863 (52.2) | 949 (7.2) | <.001 |
 Separated, divorced, bereaved | 1227 (55.5) | 833 (37.6) | 153 (6.9) |  |
 Single | 541 (36.5) | 800 (53.9) | 142 (9.6) |  |
Body mass index | Â | Â | Â | |
 <18.5 | 273 (34.7) | 422 (53.7) | 91 (11.6) | <.001 |
 <23 | 2788 (39.6) | 3681 (52.3) | 567 (8.1) |  |
 <25 | 1780 (43.3) | 2064 (50.2) | 269 (6.5) |  |
 ≥25 | 2511 (44.7) | 2723 (48.5) | 381 (6.8) |  |
Smoking status | Â | Â | Â | |
 Never smokers | 4520 (41.7) | 5502 (50.8) | 806 (7.4) | 0.63 |
 Exsmokers | 1370 (42.5) | 1610 (50.0) | 242 (7.5) |  |
 Current smokers | 1491 (41.6) | 1823 (50.9) | 270 (7.5) |  |
Drinking | Â | Â | Â | |
 Non alcohol consumption | 2306 (45.5) | 2339 (46.1) | 424 (8.4) | <.001 |
 <1 drinking episode per month | 1369 (40.7) | 1755 (52.2) | 240 (7.1) |  |
 <5 drinking episodes per month | 2115 (38.7) | 2964 (54.2) | 386 (7.1) |  |
 ≥5 drinking episodes per month | 1571 (42.9) | 1824 (49.9) | 264 (7.2) |  |
Level of daily activity | Â | Â | Â | |
 Sedentary | 789 (40.8) | 872 (45.1) | 272 (14.1) | <.001 |
 Light | 2924 (40.4) | 3831 (52.9) | 483 (6.7) |  |
 Moderate | 3032 (43.3) | 3551 (50.7) | 426 (6.1) |  |
 Heavy/extreme | 633 (43.9) | 675 (46.8) | 134 (9.3) |  |
Subjective health | Â | Â | Â | |
 Good | 2319 (40.0) | 3113 (53.6) | 372 (6.4) | <.001 |
 Fair | 3409 (40.9) | 4328 (51.9) | 599 (7.2) |  |
 Bad | 1641 (47.4) | 1477 (42.7) | 344 (9.9) |  |
Bed rest for the past month | Â | Â | Â | |
 No | 6684 (41.4) | 8284 (51.3) | 1166 (7.2) | <.001 |
 Yes | 684 (46.7) | 633 (43.2) | 148 (10.1) |  |
Absence from work for the past month | Â | Â | Â | |
 No | 4211 (41.0) | 5427 (52.9) | 631 (6.1) | <.001 |
 Yes | 277 (47.5) | 256 (43.9) | 50 (8.6) |  |