Table 1.
Multilevel mixed effects regression on effect of how sleep deprived people are perceived with respect to attractiveness, health, and tiredness
| Factors observed | Mean (SE) | Fixed effects* | SD (SE) random effects† | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Normal sleep | Sleep deprivation | z score | P value | Observer | Face | Residual | |||
| Health | 68 (2) | 63 (2) | −8.4 | 0.001 | 13 (1) | 7 (1) | 13 (0) | ||
| Attractiveness | 40 (2) | 38 (2) | −3.8 | 0.001 | 11 (1) | 6 (1) | 11 (0) | ||
| Tiredness | 44 (3) | 53 (3) | 12.4 | 0.001 | 10 (1) | 11 (2) | 18 (2) | ||
*Wald test.
†Evaluated using likelihood ratio test. Observers’ perceptions were rated using visual analogue scales of 100 mm, with 100 as the highest score. P=0.001 for all random effects.