Table 1.
Sociodemographic and lifestyle characteristics of study sample according to night shift work (N = 70)
| Variable in % (n) or arithmetic mean (standard deviation, SD) |
Total | Rotating night shift workers |
Day workers | pa |
|---|---|---|---|---|
| 100% (N = 70) | 45.7% (32) | 54.3% (38) | ||
| Sociodemographic characteristics | ||||
| Job title | < 0.001 | |||
| Nurse | 71.2% (47) | 93.3% (28) | 52.8% (19) | |
| Head nurse | 6.1% (4) | 3.3% (1) | 8.3% (3) | |
| Nurse assistant | 1.5% (1) | 3.3% (1) | 0.0% (0) | |
| Administrative personnel | 21.2% (14) | 0.0% (0) | 38.9% (14) | |
| Age (years mean, SD) | 52.0 (4.0) | 52.0 (4.0) | 52.0 (4.0) | 0.691 |
| Gender | ||||
| Female | 91.4% (64) | 87.5% (28) | 94.7% (36) | 0.402 |
| Male | 8.6% (6) | 12.5% (4) | 5.3% (2) | |
| Education | 0.369 | |||
| Compulsory schooling (elementary) | 1.6% (1) | 0.0% (0) | 2.6% (1) | |
| Secondary | 46.9% (30) | 38.5% (10) | 52.6% (20) | |
| Secondary with university entrance qualification | 29.7% (19) | 30.8% (8) | 28.9% (11) | |
| Tertiary (university degree or higher) | 21.9% (14) | 30.8% (8) | 15.8% (6) | |
| Marital status | 1.000 | |||
| Single | 12.5% (8) | 11.5% (3) | 13.2% (5) | |
| Married or in civil union | 67.2% (43) | 69.2% (18) | 65.8% (25) | |
| Divorced/widowed | 20.3% (13) | 19.2% (5) | 21.1% (8) | |
| Domestic situation (nr. of persons in household) | 0.475 | |||
| 1 | 25.4% (16) | 26.9% (7) | 24.3% (9) | |
| 2 | 25.4% (16) | 15.4% (4) | 32.4% (12) | |
| 3 | 23.8% (15) | 26.9% (7) | 21.6% (8) | |
| 4–5 | 25.4% (16) | 30.8% (8) | 21.6% (8) | |
| Ethnicity | 0.346 | |||
| White | 59.6% (31) | 54.5% (12) | 63.3% (19) | |
| Asian | 7.7% (4) | 13.6% (3) | 3.3% (1) | |
| Black or Middle East | 1.9% (1) | 4.5% (1) | 0.0% (0) | |
| Other | 30.8% (16) | 27.3% (6) | 33.3% (10) | |
| Work hours per week (mean, SD) | 39.09 (10.54) | 41.45 (9.36) | 34.92 (11.57) | 0.074 |
| Total years in alternating shifts (mean, SD) | 18.21 (11.92) | 26.76 (6.78) | 8.02 (8.02) | < 0.001 |
| Years in current rotation plan (mean, SD) | 21 (10) | 24 (9) | 14 (10) | 0.005 |
| Night shifts per month (mean, SD) | – | 5.8 (3.1) | – | – |
| Lifestyle and sleep-related characteristics | ||||
| Smoking status | 0.847 | |||
| Smoker | 31.7% (20) | 30.8% (8) | 32.4% (12) | – |
| No. of cigarettes per week (mean, SD) | 345 (233.18) | 300 (279.64) | 367.50 (219.41) | 0.901 |
| Former smoker | 22.2% (14) | 19.2% (5) | 24.3% (9) | – |
| Never smoked | 46.0% (29) | 50.0% (13) | 43.2% (16) | – |
| Current alcohol consumption | 0.685 | |||
| Yes | 38.6% (22) | 41.7% (10) | 36.4% (12) | – |
| No. of alcoholic beverages per week (mean, SD) | 1.34 (2.30) | 1.48 (2.47) | 1.24 (2.19) | 0.698 |
| No | 61.4% (35) | 58.3% (14) | 63.6% (21) | – |
| Caffeine consumption | 0.253 | |||
| Yes | 87.5% (56) | 80.8% (21) | 92.1% (35) | – |
| No. of cups of coffee per day (mean, SD) | 2.72 (1.62) | 2.42 (1.96) | 2.93 (1.30) | 0.120 |
| No. of cups of caffeinated drinks per day (mean, SD) | 3.02 (2.15) | 2.85 (2.74) | 3.15 (1.62) | 0.179 |
| No | 12.5% (8) | 19.2% (5) | 7.9% (3) | – |
| Current sleep problem | 0.159 | |||
| Yes | 62.9% (39) | 73.1% (19) | 55.6% (20) | – |
| Nights per week (mean, SD) | 3.15 (2.01) | 2.79 (1.87) | 3.50 (2.12) | 0.536 |
| No | 37.1% (23) | 26.9% (7) | 44.4% (16) | – |
| Wake up in the middle of the night | 0.447 | |||
| Yes | 69.5% (41) | 75.0% (18) | 65.7% (23) | |
| No | 30.5% (18) | 25.0% (6) | 34.3% (12) | |
| Trouble falling asleep | 0.001 | |||
| Yes | 55.4% (31) | 82.6% (19) | 36.4% (12) | |
| No | 44.6% (25) | 17.4% (4) | 63.6% (21) | |
| Daytime functioning impairment due to sleep problem | 0.351 | |||
| None | 13.1% (8) | 11.5% (3) | 14.3% (5) | |
| Minimal | 31.1% (19) | 23.1% (6) | 37.1% (13) | |
| Moderate | 37.7% (23) | 46.2% (12) | 31.4% (11) | |
| Serious | 16.4% (10) | 19.2% (5) | 14.3% (5) | |
| Severe | 1.6% (1) | 0.0% (0) | 2.9% (1) | |
| Physical activity (hours per week) | 4.39 (2.82) | 3.77 (1.86) | 4.79 (3.28) | 0.568 |
| Chronotype | ||||
| Total MEQ score (mean, SD)a | 58 (9) | 57 (9) | 60 (10) | 0.538 |
| Self-assessment | 0.895 | |||
| Clearly evening type | 6.7% (2) | 6.7% (1) | 6.7% (1) | |
| Rather evening type | 33.3% (10) | 26.7% (4) | 40.0% (6) | |
| Rather morning type | 23.3% (7) | 26.7% (4) | 20.0% (3) | |
| Clearly morning type | 36.7% (11) | 40.0% (6) | 33.3% (5) | |
aThe total morningness-eveningness questionnaire (MEQ) score was calculated by summing the scores of all 19 questions included in the questionnaire