Summary of findings 4. Morning bright light versus afternoon bright light for improving mood and alertness in daytime workers.
| Morning bright light versus afternoon bright light for improving mood and alertness in daytime workers | |||||
| Patient or population: daytime workers Setting: offices Intervention: morning bright light Comparison: afternoon bright light | |||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect with morning bright light (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | |
| Risk with afternoon bright light | Risk with morning bright light | ||||
| Alertness assessed with: visual analogue scale Scale from: 0 to 100 (better) follow‐up: 2 weeks | Mean 59 (SD 23) | Mean 66 (SD 25) | MD 7 higher (−10.18 lower to 24.18 higher) | 30 (1 RCT) | ⊕⊕⊝⊝ Low1,2 |
| Mood assessed with: SIGH‐SAD (≥ 50% reduction of SIGH‐SAD) follow‐up: 2 weeks | 426 per 1000 | 688 per 1000 (345 to 1376) | RR 1.60 (0.81 to 3.20) | 30 (1 RCT) | ⊕⊕⊝⊝ Low1,2 |
| Adverse events (frequency) follow‐up: 2 weeks | 712 per 1000 | 375 per 1000 (349 to 1000) | RR 0.53 (0.26 to 1.07) | 30 (1 RCT) | ⊕⊕⊝⊝ Low1,2 |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio; SIGH‐SAD: Structured Interview Guide for the Hamilton Depression Rating Scale‐Seasonal Affective Disorders Version. | |||||
| GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect. | |||||
1 We downgraded the level of evidence with one level, i.e. from high to moderate quality, due to risk of bias (the authors did not fully describe their randomisation method nor how or if they employed allocation concealment).
2 We downgraded the level of evidence with one level, i.e. from moderate to low quality, due to imprecision (a small sample size and a wide confidence interval including a null effect).