Table 2.
Insomnia Severity Index (ISI)/Epworth Sleepiness Scale (ESS) according to subject characteristics
| Characteristics | ISI | ESS | |||||
|---|---|---|---|---|---|---|---|
| Normal | Sub-threshold insomnia | Moderated insomnia | Severe insomnia | Normal | Daytime hypersomnia | ||
| Sex | Male | 726(65.4) | 267(24.0) | 106(9.5) | 12(1.1)c)*** | 972(87.5) | 139(12.5)a) |
| Female | 1230(56.0) | 630(28.7) | 276(12.6) | 61(2.8) | 1881(85.6) | 316(14.4) | |
| Mean age(years)b) | 48.7 ± 14.3 | 52.0 ± 13.6 | 54.6 ± 13.2 | 57.7 ± 11.9** | 49.9 ± 14.2 | 54.2 ± 13.1** | |
| Age(years)c) | 20-29 | 200(74.6) | 56(20.9) | 11(4.1) | 1(0.4)**** | 250(93.3) | 18(6.7)**** |
| 30-39 | 389(66.5) | 140(23.9) | 52(8.9) | 4(0.7) | 527(90.1) | 58(9.9) | |
| 40-49 | 409(62.3) | 164(25.0) | 70(10.7) | 13(2.0) | 570(86.9) | 86(13.1) | |
| 50-59 | 420(56.8) | 218(29.5) | 85(11.5) | 16(2.2) | 631(85.4) | 108(14.6) | |
| 60-69 | 394(51.6) | 229(30.0) | 112(14.7) | 29(3.8) | 637(83.4) | 127(16.6) | |
| 70-74 | 144(48.7) | 90(30.4) | 52(17.6) | 10(3.4) | 238(80.4) | 58(19.6) | |
| Educationc) | Never | 41(53.2) | 22(28.6) | 12(15.6) | 2(2.6)**** | 63(81.8) | 14(18.2)**** |
| Elementary School | 174(50.7) | 104(30.3) | 58(16.9) | 7(2.1) | 279(81.3) | 64(18.7) | |
| Middle school | 267(52.1) | 150(29.3) | 74(14.5) | 21(4.1) | 434(84.8) | 78(15.2) | |
| High school | 849(60.3) | 365(25.9) | 160(11.4) | 33(2.4) | 1199(85.2) | 208(14.8) | |
| College or more | 625(64.5) | 256(26.4) | 78(8.1) | 10(1.0) | 878(90.6) | 91(9.4) | |
| Residency period(year)c) | ≥15 | 446(54.0) | 253(30.6) | 108(13.1) | 19(2.3)**** | 685(82.9) | 141(17.1)*** |
| 10-14 | 381(58.2) | 179(27.3) | 76(11.6) | 19(2.9) | 571(87.2) | 84(12.8) | |
| 5-9 | 418(61.6) | 165(24.3) | 80(11.8) | 16(2.4) | 592(87.2) | 87(12.8) | |
| <5 | 442(61.7) | 195(27.2) | 68(9.5) | 11(1.5) | 625(87.3) | 91(12.7) | |
| Drinking | No | 1164(56.6) | 573(27.9) | 265(12.9) | 53(2.6)c)**** | 1776(86.4) | 279(13.6)a) |
| Yes | 792(63.2) | 324(25.9) | 117(9.3) | 20(1.6) | 1077(86.0) | 176(14.0) | |
| Smokingc) | Never | 1474(57.9) | 708(27.8) | 300(11.8) | 64(2.5)*** | 2190(86.0) | 356(14.0) |
| Past smoker | 180(65.9) | 68(24.9) | 24(8.8) | 1(0.4) | 229(83.9) | 44(16.1) | |
| Current smoker | 302(61.8) | 121(24.7) | 58(11.9) | 8(1.6) | 434(88.8) | 55(11.2) | |
| Regular Exercise | No | 1111(62.0) | 454(25.3) | 199(11.1) | 29(1.6)c)**** | 1532(85.4) | 261(14.6)a) |
| Yes | 845(55.8) | 443(29.2) | 183(12.1) | 44(2.9) | 1321(87.2) | 194(12.8) | |
| Operation or hospitalization within 1 year | No | 1830(60.5) | 801(26.5) | 329(10.9) | 65(2.2)c)**** | 2625(86.8) | 400(13.2)a)* |
| Yes | 126(44.5) | 96(33.9) | 53(18.7) | 8(2.8) | 228(80.6) | 55(19.4) | |
| Noise exposure Groupc) | Control | 376(78.8) | 75(15.7) | 25(5.2) | 1(0.2)**** | 451(94.6) | 26(5.4)**** |
| Low-exposure | 782(55.7) | 426(30.4) | 155(11.1) | 40(2.8) | 1214(86.5) | 189(13.5) | |
| High-exposure | 798(55.9) | 396(27.7) | 202(14.2) | 32(2.2) | 1188(83.2) | 240(16.8) | |
a)By Chi-square test
b)By ANOVA
c)By Mantel-Haeszel Chi-square test
*p < 0.05, **p < 0.001, ***p for trend < 0.05, ****p for trend < 0.001