Table 2.
Intervention characteristics of the included studies.
| Study | Intervention treatment | Comparison treatment | Sample size (n) | Treatment period | Shift work period | Measure period |
|---|---|---|---|---|---|---|
| Babkoff 2002 | BL and caffeinea | DL and caffeine |
EG: 6 CG: 6 |
2330–0230c | 1730–0830f,h | 0130–0430 |
| Bjorvatn 2007 | BLb | Placebo capsules |
EG: 17 CG: 17 |
0000–0500 and 1200–1430c | 0630–1830 and 1830–0630g | Every 2 h from 2000 and so on |
| Bjorvatn 2020 | BL | DL |
EG: 35 CG: 35 |
0200–0300, 0300–0400, 0400–0500 | 2200–0600 | every 2 h at 2200–0600 |
| Boivin 2012 | Intermittent BLa | No |
EG: 8 CG: 9 |
6 h from 2200, 2230, 2300, or 2330c | 8/8.5 h between 2200–0800f | Every 2 h (phase shift) or every 30 min (sleepiness) at 0600–2200 |
| Comtet 2019 | BL | DL |
EG: 18 CG: 18 |
0500–0530 | 2000–0800 | 0300, 0500, 0700, 0800 |
| Dawson 1991 | BL and DLa | DL |
EG: 6 CG: 7 |
2400–0400c | 2300–0700f,h | 0100, 0300, 0500, and 0700 |
| Dawson 1995 | BLa | DL |
EG: 8 CG: 8 |
2400–0400c | 2300–0700f,h | At night |
| Griepentrog 2018 | BL | SL |
EG: 26 CG: 17 |
1900–0700 | 1900–0700 | 0500, 0700 |
| Horowitz 2001 | BL and fixed or free sleep | RL and fixed or free sleep |
EG: 25 CG: 27 |
2300–0700 | 2300–0700, 0700–1100 | 2300–0700 |
| Karchani 2011 | BLb | RL |
EG: 45 CG: 45 |
2200, 2400, 0200 and 0400c | 0600–1400, 1400–2200, and 2200–0600 g | 2300, 0100, 0300, and 0500 |
| Kretschmer 2013 | BL and RLa | RL |
EG: 16 CG: 16 |
2200–0200, 2300–0300, 0000–0400c | 2200–0400f,h | Every 2 h/day |
| Study | Illuminance (lux) | Treatment days | Tool | Outcome | ||
|---|---|---|---|---|---|---|
| Babkoff 2002 |
E: 3000 C: 20–50 |
1 | VAS and RIA | Sleepiness and phase shift | ||
| Bjorvatn 2007 |
E: 10,000 C: 0 |
8 | KSS | Sleepiness | ||
| Bjorvatn 2020 |
E: 10,000 C: 100 |
3 | KSS | Sleepiness | ||
| Boivin 2012 | NA | 7 | VAS and RIA | Sleepiness and phase shift | ||
| Comtet 2019 |
E: 10,000 C: 8 |
1 | KSS | Sleepiness | ||
| Dawson 1991 |
E: BL 6000 and DL 150–200 C: 150–200 |
3 | Core temperature | Phase shift | ||
| Dawson 1995 |
E: 4000–7000 C: 50 |
3 | RIA | Phase shift | ||
| Griepentrog 2018 |
E: 1500–2000 C: 300 |
1 | SSS and ELISA | Sleepiness and phase shift | ||
| Horowitz 2001 |
E: 2500 C: 150 |
3 | VAS and RIA | Sleepiness and phase shift | ||
| Karchani 2011 |
E: 2500–3000 C: 300 |
2 | SSS | Sleepiness | ||
| Kretschmer 2013 |
E: BL 3000 and RL 300 C: 300 |
3 | SSS | Sleepiness |
| Study | Intervention treatment | Comparison treatment | Sample size (n) | Treatment period | Shift work period | Measure period |
|---|---|---|---|---|---|---|
| Lee 2006 | BL | DL |
EG: 11 CG: 12 |
0045–0500 | 2300–0700 | Every 30 min at 1530–1200; 0000–1800 in last day |
| Lee 2020 | BL | DL |
EG: 12 CG: 12 |
0100–0600 | 0100–0600 | Every hour at 2100–0600 |
| Lowden 2004 | BL | RL |
EG: 18 CG: 18 |
1515–2145, 2145–0630, or 2400–0630 | 1515–2145, 2145–0630, and 2400–0630 | Every 2 h at 0000–0600, 0600–1400 |
| Nagashima 2017 | BL | DL |
EG: 12 CG: 12 |
1000–1600 | 0000–0800 | Every hour at 1800–0000 |
| Sadeghniiat-Haghighi 2011 | BL | RL |
EG: 47 CG: 47 |
0030–0050, 0230–0250 | 0600–1800, 1800–0600g | 2200, 2400, 0200, 0400 |
| Smith 2009 | Intermittent BL pulse and RL | RL |
EG: 9 CG: 10 |
0045–0400 | 2300–0700 | Every 30 min/day |
| Sunde 2020 | BL | SL |
EG: 36 CG: 36 |
2300–0500 | 2300–0700 | 2330, 0100, 0230, 0400, 0530 |
| Tanaka 2011 | BL | No |
EG: 61 CG: 61 |
0730–0800 | 0800–1700, and 1630–0830 | 1000, 1400 |
| Thorne 2010 | WL and wearing sunglasses | No |
EG: 10 CG: 10 |
1300–1400 | 1800–0600, or 1900–0700 | Every 4 h/day |
| Yoon 2002 | BL | RL |
EG: 12 CG: 12 |
0100–0500 and 0830–0930 | 2200–0800 | 4 times at 2400–0600 |
| Study | Illuminance (lux) | Treatment days | Tool | Outcome | ||
|---|---|---|---|---|---|---|
| Lee 2006 |
E: 3500 C: < 50 |
2 | RIA | Phase shift | ||
| Lee 2020 |
E: 430 C: < 1 |
1 | KSS and RIA | Sleepiness and phase shift | ||
| Lowden 2004 |
E: 2500 C: 300 |
15 | KSS and RIA | Sleepiness and phase shift | ||
| Nagashima 2017 |
E: > 3000 C: < 50 |
1 | RIA | Phase shift | ||
| Sadeghniiat-Haghighi 2011 |
E: 2500 C: 300 |
1 | SSS | Sleepiness | ||
| Smith 2009 |
E: 4100 C: < 50 |
8 | RIA | Phase shift | ||
| Sunde 2020 |
E: 900 C: 90 |
3 | KSS and ELISA | Sleepiness and phase shift | ||
| Tanaka 2011 |
E: 5444–8826 C: 0 |
30 | KSS | Sleepiness | ||
| Thorne 2010 |
E: 3000 C: 0 |
4 | RIA | Phase shift | ||
| Yoon 2002 |
E: NL 4000–6000 and SL 10,000 C: RL < 200 and SL 10,000 |
3 | VAS | Sleepiness |
BL bright light, DL dim light, WL white light, NL nocturnal light, SL sunlight, RL room light, E experimental group, C control group, No no treatment, NA not available, ELISA enzyme-linked immunosorbent assay, KSS Karolinska Sleepiness Scale, RIA Radioimmunoassay, SSS Standford Sleepiness Scale, VAS Visual Analog Scale.