Table 1.
Descriptive statistics [n (%)] of the study participants and their neighborhoods by nighttime levels of traffic noise.
| Covariate (no. of missing values) | Total | Nighttime traffic noise (dB) | p-Valuea | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤ 45 | 45.1–50 | 50.1–55 | > 55 | |||||||||
| Demographic variables | ||||||||||||
| Sex | 7,019 | 0.06 | ||||||||||
| Men | 1,325 (18.9) | 860 (19.5) | 262 (17.4) | 129 (18.0) | 74 (18.6) | |||||||
| Women | 5,694 (81.1) | 3,539 (80.5) | 1,245 (82.6) | 587 (82.0) | 323 (81.4) | |||||||
| Married/cohabiting (88) | 6,931 | 0.06 | ||||||||||
| 5,000 (71.2) | 3,177 (73.0) | 1,079 (72.6) | 485 (69.2) | 259 (66.8) | ||||||||
| Obese (103) | 6,842 | 0.09 | ||||||||||
| 1,057 (15.4) | 646 (15.0) | 237 (16.1) | 108 (15.7) | 66 (17.0) | ||||||||
| Current smoker (103) | 6,916 | 0.50 | ||||||||||
| 1,108 (16.0) | 694 (16.0) | 234 (15.7) | 119 (17.0) | 61 (15.7) | ||||||||
| Physically inactive (62) | 6,957 | 0.88 | ||||||||||
| 1,813 (26.1) | 1,109 (25.4) | 417 (27.8) | 178 (25.2) | 109 (27.8) | ||||||||
| Moderate-to-heavy alcohol use (51) | 6,968 | 0.22 | ||||||||||
| 748 (10.7) | 476 (10.9) | 138 (9.2) | 79 (11.1) | 55 (14.0) | ||||||||
| Trait anxiety score (204) | 6,815 | 0.08 | ||||||||||
| Higher score | 2,870 (42.1) | 1,836 (42.9) | 612 (41.9) | 276 (40.1) | 146 (38.0) | |||||||
| Chronic disease | 7,019 | 0.35 | ||||||||||
| 1,325 (18.9) | 837 (19.0) | 286 (19.0) | 136 (19.0) | 66 (16.6) | ||||||||
| Children < 6 years of age (1,653) | 5,366 | 0.28 | ||||||||||
| 708 | 455 (13.5) | 159 (13.8) | 56 (10.4) | 38 (12.9) | ||||||||
| Occupational status (95) | 4,858 | 0.77 | ||||||||||
| High | 2,892 (41.2) | 1,797 (41.4) | 614 (41.3) | 287 (40.5) | 194 (49.6) | |||||||
| Intermediate | 3,094 (44.1) | 1,963 (45.3) | 662 (44.5) | 324 (45.8) | 145 (37.1) | |||||||
| Low | 938 (13.4) | 578 (13.3) | 211 (14.2) | 97 (13.7) | 52 (13.3) | |||||||
| Residence size (22) | 6,997 | 0.19 | ||||||||||
| Large, > 100 m2 | 1,870 (26.7) | 1,229 (28.0) | 424 (28.3) | 153 (21.5) | 64 (16.1) | |||||||
| Intermediate, 70–100 m2 | 2,846 (40.7) | 1,794 (40.9) | 604 (40.2) | 296 (41.6) | 152 (38.3) | |||||||
| Small, < 70 m2 | 2,281 (32.6) | 1,364 (31.1) | 473 (31.5) | 263 (36.9) | 181 (45.6) | |||||||
| Sleep variables | ||||||||||||
| Any symptom of insomnia (85) | 6,961 | |||||||||||
| 3,546 (51.0) | 2,228 (51.0) | 743 (49.7) | 359 (50.8) | 216 (54.8) | ||||||||
| Difficulties falling asleep (226) | 6,793 | |||||||||||
| 999 (14.7) | 628 (14.7) | 217 (14.9) | 105 (15.3) | 49 (12.6) | ||||||||
| Frequently waking up during the night (116) | 6,853 | |||||||||||
| 2,696 (39.3) | 1,692 (39.4) | 573 (38.8) | 278 (40.2) | 153 (39.3) | ||||||||
| Waking up too early in the morning (289) | 6,730 | |||||||||||
| 1,652 (24.5) | 1,034 (24.6) | 364 (25.2) | 152 (22.2) | 102 (26.3) | ||||||||
| Nonrestorative sleep (168) | 6,851 | |||||||||||
| 2,111 (30.8) | 1,324 (30.9) | 447 (30.3) | 208 (30.0) | 132 (33.9) | ||||||||
| Short sleep (71) | 6,948 | |||||||||||
| 1,568 (22.6) | 981 (22.5) | 340 (22.7) | 165 (23.4) | 82 (20.8) | ||||||||
| aInteractions between noise and covariates in a model for any symptoms of insomnia. | ||||||||||||