Weighted prevalence of selected sleep-related problems and job characteristics by usual shift worked among US workers (NHANES, 2005–2008)
| Shiftwork status* | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total (n=6338) | Regular daytime shift (n=4568) | Regular night shift (n=277) | Regular evening shift (n=381) | Rotating shift (n=570) | Another schedule† (n=540) | |||||||
| n‡ | % (95% CI) | n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | |
| Sleep-related problems | ||||||||||||
| Short sleep duration (<7 hours per weekday/workday)§ | 2512 | 37.6 (35.3 to 39.9) | 1717 | 35.9 (33.5 to 38.4) | 172 | 61.8 (55.0 to 68.3) | 157 | 39.1 (33.2 to 45.0) | 248 | 41.3 (35.5 to 47.1) | 217 | 37.1 (31.7 to 42.5) |
| Physician-diagnosed sleep disorder¶ | 343 | 6.2 (5.5 to 7.0) | 248 | 6.5 (5.8 to 7.3) | 15 | 3.8 (1.9 to 7.6)** | 19 | 4.4 (1.2 to 7.6)** | 26 | 5.9 (2.7 to 9.2) | 35 | 6.2 (3.0 to 9.4) |
| Sleeping pills/other medications to help with sleep (five or more times in preceding month) | 327 | 6.4 (5.6 to 7.3) | 238 | 6.4 (5.5 to 7.5) | 16 | 8.1 (5.4 to 12.2) | 18 | 6.4 (3.2 to 9.7) | 26 | 5.9 (3.2 to 8.6) | 29 | 6.2 (4.0 to 8.4) |
| Sleep latency/time to sleep at bedtime (≥30 min)§ | 2220 | 32.9 (30.9 to 35.0) | 1514 | 31.0 (29.0 to 33.0) | 118 | 46.2 (39.9 to 52.6) | 167 | 43.0 (36.8 to 49.3) | 252 | 42.1 (36.4 to 47.8) | 168 | 29.6 (23.0 to 36.2) |
| Ever told physician had trouble falling asleep | 1103 | 20.2 (19.2 to 21.2) | 782 | 19.8 (18.6 to 21.0) | 49 | 22.2 (15.0 to 31.5) | 60 | 15.9 (11.0 to 20.8) | 96 | 21.8 (16.6 to 27.1) | 116 | 24.1 (18.7 to 29.6) |
| Sleep quality, self-reported (five or more times in the past month) | ||||||||||||
| Trouble falling asleep§ | 824 | 14.0 (12.8 to 15.2) | 534 | 12.7 (11.4 to 14.1) | 54 | 21.7 (16.7 to 27.5) | 73 | 21.2 (15.6 to 26.8) | 92 | 17.5 (12.4 to 22.7) | 71 | 14.4 (10.5 to 18.2) |
| Wake up during the night with trouble getting back to sleep | 1015 | 17.4 (16.1 to 18.8) | 718 | 17.1 (15.7 to 18.5) | 52 | 19.9 (14.2 to 27.2) | 65 | 19.0 (13.7 to 24.2) | 81 | 14.9 (11.6 to 18.2) | 99 | 20.2 (15.7 to 24.8) |
| Wake up too early in the morning and unable to get back to sleep§ | 874 | 14.3 (13.0 to 15.6) | 633 | 14.2 (12.8 to 15.7) | 46 | 20.6 (14.8 to 27.9) | 52 | 15.0 (11.0 to 19.0) | 61 | 9.7 (7.2 to 12.3) | 82 | 15.7 (12.1 to 19.3) |
| Feel unrested during the day regardless of hours of sleep | 1528 | 26.6 (25.1 to 28.2) | 1054 | 25.5 (23.6 to 27.4) | 75 | 32.1 (25.2 to 40.0) | 100 | 28.7 (22.0 to 35.4) | 155 | 28.5 (21.2 to 35.8) | 144 | 31.4 (27.3 to 35.6) |
| Feel excessively or overly sleepy during the day | 1020 | 17.0 (15.5 to 18.5) | 695 | 16.2 (14.7 to 17.8) | 56 | 22.3 (17.5 to 27.9) | 64 | 17.6 (11.7 to 23.4) | 104 | 17.5 (12.5 to 22.4) | 101 | 20.7 (16.3 to 25.1) |
| Not getting enough sleep§ | 1587 | 26.9 (25.3 to 28.5) | 1061 | 25.2 (23.4 to 27.1) | 92 | 37.2 (31.6 to 43.2) | 122 | 31.9 (26.7 to 37.2) | 159 | 27.6 (20.9 to 34.3) | 153 | 32.8 (28.2 to 37.4) |
| Sleep quality index§,†† | ||||||||||||
| Good | 3555 | 53.5 (52.0 to 54.9) | 2646 | 55.2 (53.2 to 57.3) | 142 | 46.9 (39.9 to 54.0) | 192 | 48.0 (40.0 to 56.0) | 299 | 50.7 (44.1 to 57.3) | 274 | 47.2 (42.5 to 51.9) |
| Moderate | 1620 | 27.3 (25.8 to 28.9) | 1120 | 26.4 (24.5 to 28.4) | 60 | 22.4 (17.4 to 28.2) | 107 | 28.9 (23.8 to 34.0) | 165 | 30.1 (24.3 to 35.8) | 168 | 34.1 (29.0 to 39.3) |
| Poor | 1163 | 19.2 (17.6 to 20.8) | 802 | 18.4 (17.0 to 19.9) | 75 | 30.7 (25.7 to 36.2) | 82 | 23.1 (16.8 to 29.3) | 106 | 19.3 (14.2 to 24.3) | 98 | 18.7 (13.9 to 23.5) |
| Sleep-related ADL | ||||||||||||
| Difficulty concentrating | 1387 | 22.9 (21.5 to 24.3) | 942 | 22.1 (20.8 to 23.5) | 83 | 30.4 (22.9 to 39.0) | 95 | 22.5 (16.6 to 28.4) | 122 | 22.0 (16.9 to 27.1) | 144 | 26.7 (21.1 to 32.3) |
| Difficulty remembering§ | 1086 | 17.3 (16.2 to 18.5) | 734 | 16.4 (15.1 to 17.7) | 67 | 25.7 (20.4 to 31.9) | 79 | 18.4 (13.6 to 23.1) | 89 | 16.0 (12.1 to 20.0) | 117 | 22.5 (18.6 to 26.3) |
| Difficulty eating | 207 | 2.8 (2.3 to 3.3) | 129 | 2.3 (1.9 to 2.8) | 15 | 3.2 (1.6 to 6.3)** | 22 | 6.3 (2.8 to 9.8) | 27 | 4.6 (2.1 to 7.0) | 14 | 2.6 (0.8 to 4.3)** |
| Difficulty with a hobby | 782 | 13.4 (12.3 to 14.6) | 531 | 13.2 (12.0 to 14.4) | 48 | 18.6 (14.0 to 24.3) | 51 | 12.2 (7.7 to 16.7) | 77 | 14.8 (10.9 to 18.8) | 75 | 13.0 (9.2 to 16.8) |
| Difficulty getting things done because too sleepy to drive | 721 | 11.3 (10.3 to 12.3) | 465 | 10.5 (9.5 to 11.5) | 46 | 16.9 (11.8 to 23.7) | 60 | 13.2 (8.3 to 18.1) | 70 | 11.3 (8.1 to 14.6) | 80 | 14.3 (10.1 to 18.6) |
| Difficulty with finance | 749 | 11.9 (10.7 to 13.2) | 478 | 11.3 (10.1 to 12.6) | 34 | 13.4 (8.5 to 20.5) | 68 | 12.9 (9.7 to 16.2) | 83 | 12.5 (8.7 to 16.4) | 86 | 15.4 (11.5 to 19.3) |
| Difficulty with paid or volunteer work | 632 | 10.5 (9.6 to 11.4) | 436 | 10.4 (9.3 to 11.7) | 37 | 13.1 (8.7 to 19.2) | 47 | 11.2 (7.9 to 14.6) | 57 | 8.7 (6.4 to 11.0) | 55 | 10.8 (7.5 to 14.0) |
| Difficulty maintaining phone conversation§ | 605 | 8.4 (7.5 to 9.4) | 360 | 7.1 (6.2 to 8.0) | 46 | 15.0 (10.2 to 21.6) | 58 | 14.2 (9.8 to 18.5) | 80 | 12.7 (8.5 to 16.8) | 61 | 10.0 (6.6 to 13.4) |
| Impaired ADL score§,‡‡ | 1545 | 24.8 (23.1 to 26.5) | 1030 | 23.7 (22.2 to 25.3) | 97 | 36.2 (28.8 to 44.4) | 118 | 29.1 (23.1 to 35.1) | 147 | 23.5 (18.5 to 28.4) | 153 | 27.7 (22.3 to 33.1) |
| Insomnia§,§§ | 537 | 8.8 (7.9 to 9.8) | 368 | 8.4 (7.5 to 9.5) | 41 | 18.5 (13.2 to 25.4) | 36 | 9.7 (6.6 to 12.8) | 48 | 9.3 (5.9 to 12.8) | 44 | 7.0 (4.3 to 9.7) |
| Job characteristics | ||||||||||||
| Hours worked in all jobs in preceding week (≥48)§ | 1635 | 30.8 (28.7 to 33.0) | 1155 | 30.0 (27.9 to 32.3) | 80 | 29.8 (24.6 to 35.6) | 65 | 22.2 (17.7 to 26.7) | 149 | 29.6 (24.6 to 34.6) | 186 | 43.7 (38.1 to 49.4) |
| Years worked in current/main job (≥10 years)§ | 1610 | 28.2 (25.9 to 30.6) | 1261 | 29.9 (27.3 to 32.6) | 45 | 15.1 (10.4 to 21.3) | 47 | 13.1 (7.4 to 18.7) | 81 | 19.8 (14.0 to 25.7) | 176 | 36.1 (30.0 to 42.2) |
| Occupation categories§ | ||||||||||||
| White collar | 3117 | 56.7 (53.7 to 59.8) | 2369 | 60.2 (56.8 to 63.4) | 84 | 34.1 (26.6 to 42.5) | 134 | 33.3 (28.3 to 38.4) | 253 | 48.8 (42.5 to 55.0) | 277 | 58.2 (51.7 to 64.7) |
| Service | 1427 | 17.8 (16.2 to 19.5) | 859 | 14.2 (12.7 to 15.9) | 95 | 32.1 (26.5 to 38.2) | 141 | 38.5 (32.8 to 44.1) | 197 | 29.4 (24.0 to 34.8) | 134 | 19.6 (16.1 to 23.0) |
| Farm and blue collar | 1782 | 25.5 (23.1 to 28.0) | 1332 | 25.6 (23.1 to 28.4) | 98 | 33.8 (28.2 to 39.9) | 106 | 28.2 (21.6 to 34.8) | 118 | 21.8 (15.9 to 27.8) | 128 | 22.2 (16.4 to 27.9) |
*Among workers, 72.1% reported that they usually worked a regular daytime shift, 4.4% worked a regular night shift, 6.0% worked a regular evening shift, 9.0% worked a rotating shift and 8.5% had another schedule (excluded two participants with unknown shiftwork status).
†No additional information is available on this shift category. This category was selected by the participant if none of the other categories applied. It could include a split shift consisting of two distinct work periods each day, an irregular schedule arranged by the employer or any other schedule not already specified.
‡Unweighted sample size.
§Wald χ2 test for equal prevalence of sleep or job characteristic across shiftwork status, p<0.05.
¶Participant ever told by a doctor or other health professional that they had a sleep disorder, including sleep apnoea, insomnia, restless leg syndrome or ‘other’.
**Estimates have a RSE >30% and ≤50% and should be interpreted with caution as they do not meet standards of reliability/precision.
††Participants categorised as having poor sleep quality if the response to any of the six self-reported sleep quality items was 16–30 times/month; else as moderate sleep quality if any response was 5–15 times/month; and all others as having good sleep quality.
‡‡Response to each of the eight ADL items on a 0–3 scale, with 0=no difficulty, 1=a little difficulty, 2=moderate difficulty and 3=severe difficulty. Participants were dichotomised at 2 (sample mean score of eight completed items): a score ≥2 is considered to indicate a greater daily sleep-related impairment than a score <2.
§§Participants with poor sleep quality and impaired ADL score.
ADL, activities of daily living; NHANES, National Health and Nutrition Examination Survey; RSE, relative SE.