Actigraph estimates of the sleep of Australian midwives: the impact of shift work.

Midwives often work night and rotating shift schedules, which can lead to sleep disturbances, increased fatigue, and greater likelihood of accidents or errors. This study investigated the sleep of midwives (n = 17) in an Australian metropolitan hospital. Midwives completed work and sleep logbooks and wore wrist actigraphs for 28 days. Midwives worked combinations of morning, afternoon, and/or night shifts on constant (n = 6) or rotating schedules (n = 11). They obtained less than recommended amounts of sleep, getting only 6-7 hr per 24-hr period. Morning shifts were associated with the lowest sleep durations, lowest subjective sleep quality, and highest postsleep fatigue ratings. Despite the significantly higher amount of wake after sleep onset (51 min), the sleep before afternoon shifts had significantly lower postsleep fatigue ratings and was rated as significantly higher quality than sleep before other shifts or days off. Those who were married or living with a partner reported significantly more sleep and lower postsleep fatigue than those who were separated or divorced (p < .05). Seventy-one percent of midwives took naps, primarily before night shifts, with nearly 40% of nightshifts preceded by a nap. Average nap durations were nearly 1.5 hr. Midwives reported feeling moderately to very physically or mentally exhausted on 22-50% of all shifts and days off. Exhaustion was most common on night shift. This study suggests that midwives may be suffering from chronic sleep loss and as a consequence may be at risk of impairments in functioning that accompany fatigue.

The relationship between subjective and objective sleepiness and performance during a simulated night-shift with a nap countermeasure.

The aim of the present study was to investigate the relationship between perceived and actual sleepiness and performance during a simulated night-shift that included a 30-min night-nap as an on-duty sleepiness countermeasure. Twenty-four healthy young adults (nine males, fifteen females) participated in a repeated measures design comprising two experimental conditions: no night-nap and 30-min night-nap. Both groups were given a 2-h prophylactic afternoon sleep opportunity (1500-1700 h). Measures of subjective sleepiness (Stanford Sleepiness Scale, Karolinska Sleepiness Scale and Visual Analogue Scale), objective sleepiness (sleep latency tests), objective performance (Symbol-Digit Substitution Task) and reaction time (Psychomotor Vigilance Task) were taken before the night-nap (0230 h) and at several intervals post-nap. Time-series correlation analyses indicated that subjective sleepiness was less correlated with objective sleepiness and objective performance when participants were given a 30-min night-nap. However subjective sleepiness and reaction time performance was strongly correlated in both conditions, and there was no significant difference between the nap and no-nap conditions. Consistent with previous research, results of the present study indicate that subjective and objective indicators of sleepiness and performance may not always correspond, and this relationship may be reduced by the inclusion of a night-nap.