Crude and adjusted means of morning MT6s concentrations by selected characteristics of current rotating night shift work: a cross-sectional study of Polish nurses and midwives
| Current rotating night shift work characteristic | n | Morning MT6s (ng/mg Cr), mean (95% CI) | Adjusted* morning MT6s (ng/mg Cr), mean (95% CI) |
| Current night shift work frequency per month (nights) | |||
| 2–7 | 312 | 45.9 (42.5 to 49.4) | 47.4 (44.3 to 50.6) |
| 8+ | 42 | 37.3 (28.7 to 45.8) | 37.9 (29.8 to 44.7) |
| p | 0.078 | 0.019 | |
| Activities at work during the night shift† | |||
| 1‡ | 27 | 47.6 (35.6 to 59.7) | 49.4 (38.6 to 60.1) |
| 1 and 2 or 2 | 241 | 45.8 (41.8 to 49.8) | 46.1 (42.6 to 49.6) |
| Any combination with 3 | 78 | 41.7 (35.0 to 48.3) | 45.6 (39.5 to 51.8) |
| p-trend | 0.278 | 0.633 | |
| Napping during the night shift between 23:00 and 3:00† | |||
| No | 185 | 44.2 (39.8 to 48.6) | 44.6 (40.7 to 48.5) |
| Yes | 161 | 45.9 (41.1 to 50.8) | 48.2 (43.8 to 52.6) |
| p | 0.609 | 0.231 | |
| Duration of napping (if naps between 23:00 and 3:00) (hours)† | |||
| 0 | 185 | 44.2 (39.8 to 48.6) | 44.6 (40.7 to 48.5) |
| ≤2 | 72 | 40.5 (33.8 to 47.3) | 43.7 (37.5 to 50.0) |
| >2 | 89 | 50.5 (43.7 to 57.3) | 52.0 (46.0 to 58.3) |
| p | 0.202 | 0.067 | |
| Duration of activity during the night shift (hours)† | |||
| <10 | 92 | 50.0 (43.3 to 56.7) | 51.1 (45.1 to 57.0) |
| ≥10–14 | 254 | 43.2 (39.5 to 47.0) | 44.6 (41.2 to 47.9) |
| p | 0.079 | 0.060 | |
| Light at work† | |||
| Dim | 151 | 46.1 (41.0 to 51.1) | 46.7 (42.3 to 51.1) |
| Full light | 157 | 44.3 (39.4 to 49.1) | 45.7 (41.3 to 50.0) |
| Surgical lamp | 38 | 43.7 (34.0 to 53.5) | 46.9 (38.0 to 55.8) |
| p-trend | 0.588 | 0.900 | |