Table S2.
Reported light and objective sleep (actigraphy) by shift type
| After turning off the light/when you woke up for the day, was there any light still visible in your room? | ||||||||
|---|---|---|---|---|---|---|---|---|
| BT, mean ± SEM | WT, mean ± SEM | |||||||
| Yes | No | P-value (n) | Yes | No | P-value (n) | |||
| SOL Day | 8.73±1.73 | 5.97±2.40 | ||||||
| Night | 5.33±1.64 | 9.08±2.40 | ||||||
| Both | 7.03±1.19 | 7.52±1.70 | 0.79 | |||||
| TST Day | 409.67±17.31 | 433.40±24.16 | 431.92±20.27 | 373.60±27.83 | ||||
| Night | 355.65±16.38 | 468.91±24.13 | 387.97±18.16 | 349.59±49.30 | ||||
| Both | 382.66±11.92 | 451.15±17.08 | <0.001* | 409.95±13.61 | 361.59±28.30 | 0.09 | ||
| WASO Day | 50.92±6.59 | 45.43±8.48 | 52.17±6.37 | 42.08±8.37 | ||||
| Night | 54.36±6.20 | 58.27±8.28 | 55.63±5.76 | 51.62±14.18 | ||||
| Both | 52.64±4.52 | 51.85±5.93 | 0.89 | 53.90±4.29 | 46.85±8.23 | 0.38 | ||
| SE Day | 87.60±1.50 | 89.13±1.82 | 87.94±1.51 | 88.16±1.82 | ||||
| Night | 85.77±1.41 | 86.80±1.75 | 86.20±1.39 | 83.48±2.78 | ||||
| Both | 86.69±1.03 | 87.97±1.27 | 0.25 | 87.07±1.02 | 85.82±1.66 | 0.40 | ||
| If you answered “yes”, would you describe the light source as artificial (eg, lamp or ceiling fixture), natural (eg, sun, stars, or moon), or both? | ||||||||
| Artificial | Natural | Both | P-value (n) | Artificial | Natural | Both | P-value (n) | |
| SOL Day | 10.18±2.30 | 8.53±3.33 | 4.78±4.80 | |||||
| Night | 11.51±4.41 | 4.80±2.20 | 4.20±2.84 | |||||
| Both | 10.85±2.49 | 6.66±2.00 | 4.49±2.79 | 0.20 | ||||
| TST Day | 421.28±23.92 | 384.53±34.89 | 408.19±49.76 | 343.89±33.00 | 455.59±26.55 | 426.45±34.78 | ||
| Night | 420.65±43.93 | 330.66±22.83 | 373.52±29.55 | NA | 388.97±19.68 | 386.09±36.22 | ||
| Both | 420.97±25.01 | 357.60±20.85 | 390.86±28.94 | 0.14 | 343.89±33.00 | 422.28±16.52 | 406.27±25.11 | <0.05 |
| WASO Day | 52.88±8.85 | 49.49±12.99 | 48.88±17.90 | 30.93±9.90 | 56.08±8.46 | 51.75±10.63 | ||
| Night | 70.11±14.52 | 54.08±8.35 | 48.21±10.80 | NA | 59.41±6.55 | 40.57±11.31 | ||
| Both | 61.50±8.50 | 51.79±7.72 | 48.55±10.45 | 0.51 | 30.93±9.90 | 57.74±5.35 | 46.16±7.76 | <0.05 |
| SE Day | 87.24±1.84 | 87.21±2.68 | 88.57±3.61 | 88.16±1.98 | 87.92±1.70 | 88.77±2.13 | ||
| Night | 84.17±2.81 | 84.99±1.73 | 87.97±2.21 | NA | 85.71±1.32 | 88.60±2.26 | ||
| Both | 85.71±1.68 | 86.10±1.60 | 88.27±2.12 | 0.56 | 88.16±1.98 | 86.82±1.08 | 88.69±1.55 | 0.54 |
| Were you able to see objects in your room? | ||||||||
| Yes | No | P-value (n) | Yes | No | P-value (n) | |||
| SOL Day | 8.96±1.58 | 3.96±2.74 | ||||||
| Night | 5.43±1.55 | 8.84±2.38 | ||||||
| Both | 7.19±1.11 | 6.40±1.81 | 0.69* | |||||
| TST Day | 415.23±16.85 | 422.67±28.83 | 419.13±18.57 | 371.59±52.62 | ||||
| Night | 358.74±16.44 | 465.50±24.97 | 386.36±17.62 | 371.96±59.47 | ||||
| Both | 386.98±11.77 | 444.08±19.07 | <0.01* | 402.74±12.80 | 371.77±39.71 | 0.44 | ||
| WASO Day | 50.56±6.37 | 44.69±9.81 | 50.20±6.06 | 35.28±15.32 | ||||
| Night | 54.70±6.10 | 57.42±8.41 | 55.42±5.73 | 54.66±16.94 | ||||
| Both | 52.63±4.41 | 51.05±6.46 | 0.81 | 52.81±4.17 | 44.97±11.42 | 0.49 | ||
| SE Day | 87.89±1.49 | 88.68±2.08 | 87.95±1.47 | 89.88±3.05 | ||||
| Night | 85.82±1.42 | 86.72±1.80 | 86.07±1.39 | 85.29±3.27 | ||||
| Both | 86.85±1.03 | 87.70±1.38 | 0.50 | 87.01±1.01 | 87.58±2.24 | 0.79 | ||
| If you answered “yes”, did visible objects appear to be in shades of gray or in color (even if less vivid)? | ||||||||
| Color | Gray | P-value (n) | P-value (n) | |||||
| SOL Day | 11.48±2.67 | 8.23±2.07 | ||||||
| Night | 5.22±2.19 | 5.67±2.18 | ||||||
| Both | 8.35±1.73 | 6.95±1.50 | 0.53 | |||||
| TST Day | 441.19±21.78 | 398.68±15.82 | 433.88±20.42 | 400.14±21.95 | ||||
| Night | 291.00±17.82 | 428.45±17.46 | 364.24±17.56 | 488.82±33.78 | ||||
| Both | 366.10±14.07 | 413.56±11.78 | <0.05,** | 399.06±13.46 | 444.48±20.14 | <0.05* | ||
| WASO Day | 61.99±10.70 | 43.95±9.33 | 56.81±6.94 | 42.06±7.31 | ||||
| Night | 39.83±8.93 | 68.67±8.95 | 53.77±6.17 | 62.93±10.90 | ||||
| Both | 50.91±6.97 | 56.31±6.46 | 0.49* | 55.29±4.64 | 52.50±6.56 | 0.68 | ||
| SE Day | 86.25±2.11 | 88.44±1.84 | 87.37±1.58 | 88.60±1.63 | ||||
| Night | 86.11±1.76 | 85.55±1.76 | 86.11±1.43 | 85.91±2.30 | ||||
| Both | 86.18±1.37 | 87.00±1.28 | 0.59 | 86.74±1.07 | 87.26±1.41 | 0.69 | ||
Notes: Responses to light questions and corresponding estimated marginal means of actigraphy-based sleep variables ± SEM for each response. Responses to light questions are shown by column, organized by BT and WT, and sleep variables are shown in rows. Values vary slightly here from those reported in Table 2, due to inclusion here of only day and night workers (no administrator) and of shift and its interaction with response in all models. All P-values are for main effects for response only.
P<0.05, response–shift type interaction;
P<0.05, shift type. Subject numbers by response and shift type are the same as those reported in Table S1.
Abbreviations: BT, bedtime; WT, wake time; NA, not applicable; SOL, sleep-onset latency; TST, total sleep time; WASO, wake after sleep onset; SE, sleep efficiency.