Table 2 Multilevel, linear mixed models of the relationship between menstrual phase, covariates, and sleeping WST
Model 1Model 2Model 3Model 4Model 5Model 6Model 7Model 8
Cycle phase
MenstrualReferenceReferenceReferenceReferenceReferenceReferenceReferenceReference
Follicular−0.03 (0.03)−0.01 (0.03)−0.03 (0.03)−0.02 (0.00)−0.03 (0.03)−0.03 (0.03)−0.03 (0.03)−0.03 (0.03)
Fertile−0.13§ (0.02)−0.12§ (0.01)−0.13§ (0.02)0.13§ (0.00)−0.12§ (0.01)−0.13§ (0.02)−0.13§ (0.02)−0.13§ (0.02)
Early-luteal0.24§ (0.02)0.24§ (0.02)0.24§ (0.02)0.24§ (0.00)0.24§ (0.02)0.24§ (0.02)0.24§ (0.02)0.23§ (0.02)
Late-luteal0.37§ (0.03)0.38§ (0.03)0.37§ (0.03)0.37§ (0.00)0.37§ (0.01)0.37§ (0.03)0.37§ (0.03)0.37§ (0.03)
Meal1
Small or no foodReference
Medium-sized−0.02* (0.01)
Large−0.03‡ (0.01)
Body mass index (kg/m2)−0.05§ (0.01)
Coffee1
No coffeeReference
> =1−0.01 (0.01)
Exercise1
No exerciseReference
<60 min0.01 (0.01)
>60 min0.02 (0.01)
Sexual intercourse1−2.30† (0.01)
Alcohol1
No alcoholReference
1–4 units0.00 (0.01)
≥5 units0.06‡ (0.02)
Age (years)0.02 (0.01)
Spotting−0.01 (0.02)
  • Unstandardized b-coefficient values reported with S.E.M. in parentheses.

  • 1 Within 3 h preceding the onset of sleep; *, †, ‡, § refer to P<0.10, 0.05, 0.01, 0.001, respectively.