Actual and perceived sleep: associations with daytime functioning among postpartum women.

Sleep and wake have a homeostatic relation that influences most aspects of physiology and waking behavior. Sleep disturbance has a detrimental effect on sleepiness and psychomotor vigilance. The purpose of this study was to identify which actual or perceived sleep characteristics accounted for the most variance in daytime functioning among postpartum mothers. Seventy first-time postpartum mothers' actual sleep (actigraphically estimated: total sleep time, number of wake bouts, length of nocturnal wake, and sleep efficiency) and perceived sleep (self-reported: number of awakenings, wake time, and sleep quality) were measured along with their daytime functioning (Stanford Sleepiness Scale [SSS], Epworth Sleepiness Scale [ESS], Visual Analogue of Fatigue Scale [VAFS], and morning Psychomotor Vigilance Test [PVT]). Data were repeatedly collected from the same sample during postpartum weeks 2, 7, and 13. Four stepwise linear regressions were calculated for each postpartum week to examine which objective and/or subjective variable(s) accounted for the most variance in daytime functioning. The SSS and VAFS were both most consistently associated with perceived sleep quality. The ESS was most consistently associated with actual total sleep time. PVT performance was most consistently associated with estimates of actual and perceived sleep efficiency. Actual and perceived sleep profiles were differentially associated with specific daytime functions. These results from postpartum mothers may indicate that populations who experience specific forms of sleep disturbance (e.g. fragmentation and/or deprivation) may also experience specific daytime conditions.