Influence of shift work on rest-activity rhythms, sleep quality, and fatigue of female nurses.

Female nurses working rotating shifts must change their daily routines often, which affects their biological circadian rhythms and could cause sleep disorders and fatigue. The objective of this study was to compare the sleep-wake rhythms, sleep quality, and fatigue of female nurses working rotating shifts and fixed day shifts and to analyze the factors that influence their fatigue. Participants comprised a shift worker group of 101 nurses and a day worker group of 76 nurses. Following the collection of basic information of the nurses and their scores in the various constructs of the Pittsburg Sleep Quality Index (PSQI) and the Checklist Individual Strength (CIS) questionnaire, each nurse wore an actigraph for seven consecutive days to collect for analysis the sleep-wake rhythm parameter dichotomy index (I < O) and durations of continuous sleep and wake. Multivariable linear regression was then used to determine whether the influence of various variables on fatigue differed between the two groups. Results revealed that the sleep-wake rhythm parameter I < O of the day worker group was significantly higher than that of the shift worker group (t = 5.08, p < .001). The shift worker group exhibited significantly higher PSQI global scores (t = -2.00, p = .047), longer total sleep time (t = 2.07, p = .040), poorer habitual sleep efficiency (t = -3.06, p = .003), and greater use of sleeping medication (t = -2.90, p = .004) than did the day worker group. Multivariable linear regression was performed to analyze the important predictors of the CIS score in the two groups with body mass index, age, work experience, marital status, educational background, department of employment, shift type at the time of recruitment, sleep-wake rhythm parameter I < O, and quality of sleep as independent variables. Results indicated that in the shift worker group, the overall explanatory power (R2) of the multivariable linear regression model was 22.9% (F = 3.01, p = .003), and only the PSQI global score (ß = 0.33, p = .003) influenced the CIS score. In the day worker group, the various variables did not influence the CIS score in the multivariable linear regression model. Although the female nurses working rotating shifts spent more time in bed, their sleep-wake rhythms and sleep quality were poorer than those of the day worker group. Furthermore, the sleep quality of female nurses in the shift worker group had a significant impact on their fatigue. In other words, for female nurses who must work rotating shifts, sleep quality determines whether fatigue can be reduced. The shift-working nurses themselves should implement sleep management, such as avoiding disruptions to their sleep-wake rhythm and improving sleep quality, which should be effective strategies to reduce fatigue.

Differences in workday sleep fragmentation, rest-activity cycle, sleep quality, and activity level among nurses working different shifts.

Schedule changes associated with rotating shifts can interfere with the circadian rhythms of nurses and thereby affect their sleep duration, sleep quality, work efficiency, and work performance. The objectives of this study was to investigate differences in workday sleep fragmentation, rest-activity cycle, sleep quality, and activity level among nurses working different shifts. After filling out a basic information questionnaire and completing the Pittsburgh Sleep Quality Index (PSQI) questionnaire, participants were asked to wear an actigraph and keep sleep records for seven consecutive days. Data pertaining to wake after sleep onset (WASO), 24-hour autocorrelation coefficient (r24), and daytime activity mean was collected in order to investigate workday sleep fragmentation, rest-activity cycle, and daytime activity level. We obtained complete questionnaires and data from 191 nurses. Day- and evening-shift nurses had more regular workday rest-activity cycles than did night-shift nurses (F = 51.26, p < .001). After controlling for r24 coefficients, we determined that nurses who experienced greater workday sleep fragmentation had higher PSQI scores (ß = .18, p = .008). After controlling for WASO times, we determined that nurses who had more regular rest-activity cycles on workdays had lower PSQI scores (ß = - .16, p = .036). After controlling for shift type and WASO times, we determined that nurses with higher PSQI scores displayed lower activity levels (ß = - .21, p = .015) and those with higher r24 coefficients displayed higher activity levels (ß = .18, p = .040) on workdays. We then examined the causal path relationships. Among the shifts, only the day-shift nurses had a higher r24 (ß = -.59, p < .001) than did the night-shift nurses; WASO exerted a significant impact on PSQI scores (ß = .20, p = .002); r24 had a significant and negative influence on PSQI scores (ß = -.38, p < .001), and PSQI scores significantly and negatively influenced workday activity levels (ß = -.20, p = .006). This study determined that day- and evening-shift nurses enjoyed more regular and consistent rest-activity cycles than did night-shift nurses; nurses with greater workday sleep fragmentation and/or more irregular rest-activity cycles experienced poorer sleep quality; and nurses suffering from poorer sleep quality displayed lower daytime activity levels on workdays.

Enhanced sensitivities for the searches of neutrino magnetic moments through atomic ionization.

A new detection channel on atomic ionization for possible neutrino electromagnetic interactions is identified and studied. Significant sensitivity enhancement is demonstrated when the energy transfer to the target is of the atomic-transition scale. The interaction cross section induced by neutrino magnetic moments (µ(ν)) is evaluated with the equivalent photon method. A new limit of µ(ν)(ν[over ¯](e))<1.3×10(-11) µ(B) at 90% confidence level is derived by using current reactor neutrino data. Potential reaches for future experiments are explored. Experiments with sub-keV sensitivities can probe µ(ν) to 10(-13) µ(B). Positive observations of µ(ν) in this range would imply that neutrinos are Majorana particles.