Perceptions of Sleep Quality, Fatigue, and Cognition Among Women Shift Workers.

OBJECTIVE: To explore the perceptions of sleep quality, levels of fatigue, and cognitive executive function in women shift workers. DESIGN: Qualitative, descriptive study of a sample of participants who participated in a cross-sectional, mixed-methods study. SETTING: Online focus groups. PARTICIPANTS: Women shift workers (N = 14) recruited from the southeastern United States. METHODS: Four focus groups were conducted using the Zoom online videoconferencing platform. Transcripts were coded inductively, and data were analyzed using a thematic analysis approach. RESULTS: Five major themes were developed from the data: Lots of Sleep Lost, Day Sleep Difficulties, Negative Consequences, Missing Out, and Not in My Own Thoughts. CONCLUSION: Shift work is associated with sleep loss, which has a negative impact on women's emotional, mental, and physical health. Further nursing science investigation into strategies to enable women to improve their sleep quality, sleep quantity, and social/domestic environment is warranted. Education to increase sleep knowledge and decrease accidents and errors that can result from insufficient sleep is vital.

Association Between Shift Work and Clean Room Environment on Self-reported Premenstrual Symptoms and Menstrual Pain in Taiwan.

Background: Limited research has delved into the effects of work characteristics on premenstrual symptoms (PMS) in women, which can influence work performance and overlook potential hazards for women in their work environments. This study aimed to investigate the impact of shift work and working in a clean room on premenstrual symptoms, menstrual status, and menstrual pain among employed females in an electronics manufacturer. Methods: A retrospective cohort study was conducted on menstruating female employees between August and December 2014, aged 18-55, who received regular employee health checks. Questionnaires were designed to collect information on demographics, personal lifestyle, menstrual status, menstrual pain scores, and self-reported premenstrual symptoms. Results: Among 7,193 participants, 18.6% reported moderate to severe menstrual pain affecting their work. Female workers who reported shift work showed an increased prevalence of moderate to severe premenstrual symptoms, including fatigue (RR = 1.20), somatic discomforts (RR = 1.04), diarrhea (RR = 1.04), and tension (RR = 1.05). Additionally, shift work was associated with an elevated risk of experiencing a moderate or significant impact of menstrual pain on work (RR = 1.03), menstrual irregularity (RR = 1.30), and high menstrual pain (RR = 1.23). Working in a clean room was associated with an increased risk of high menstrual pain (RR = 1.13). Subjects working shifts in a clean room had the highest pain scores compared to the other groups. Conclusion: This study underscores the association of work-related factors on PMS in female employees. Our findings contribute to a better understanding of premenstrual symptoms in female workers with different work characteristics, emphasizing the potential hazards of work-related factors on female employees.

Influence of shift work on sleep quality and circadian patterns of heart rate variability among nurses.

Background: Shift work implementation is essential for providing continuous patient care in hospitals. However, working in shifts on a routine basis may disrupt the circadian pattern and alter the sleep-wakefulness cycle in nurses. Stress due to shift work can influence the adaptability of the cardiovascular system, produce psychophysiological strain and deteriorate work performance in female nurses. Objective: This study investigated the effect of morning and night shift work on sleep quality and circadian patterns governing heart rate variability (HRV) in female nurses working in a tertiary care hospital. Methods: Thirty-eight healthy female nurses were recruited. Frequency and time domain parameters of HRV were recorded as markers of cardiac autonomic function. A student t-test was used to investigate differences in HRV between morning and night shift workers. Mann-Whitney non-parametric test was applied for the difference between Pittsburgh Sleep Quality Index (PSQI) scores in the two groups. Results: Standard deviation of the normal-to-normal interval (SDNN) (msec), total power (ms2) and high-frequency (HF) band power (ms2) were significantly reduced in night shift nurses than in morning shift nurses. The low-frequency (LF)/HF ratio was significantly increased in night shift nurses. The differences in standard deviation of the averages of NN intervals (SDaNN) (msec), root mean square of successive differences between adjacent NN intervals (RMSSD), mean NN, very low-frequency (VLF) band power (ms2) and LF band power (ms2) were not statistically significant. The global PSQI score was significantly higher among night shift workers than in morning shifts. Conclusion: Inadequate sleep can disrupt the body's ability to regulate heart rhythm and increase the risk of cardiovascular diseases and mortality. The research suggests a propensity for autonomic imbalance in night shift workers when compared to their counterparts on morning shifts.

Evaluating the impact of shift work on the risk of cardiometabolic disease: A Mendelian randomization study.

BACKGROUND AND AIMS: Evidence is increasingly suggesting that shift work is a risk factor for cardiometabolic disease. However, the causal relationship between shift work and cardiometabolic disease is not yet fully understood. In this study, we employed two-sample Mendelian randomization (MR) to investigate the causal relationship between shift work and the risk of cardiometabolic outcomes. METHODS AND RESULTS: Genome-wide association study (GWAS) statistics for shift work were obtained from the UK Biobank. Mendelian randomization analyses were conducted to explore the causal effects of shift work on cardiometabolic outcomes, using single-nucleotide polymorphisms (SNPs) as instrumental variables. The results suggested a causal effect between shift work and body mass index, body fat percentage, triglycerides, high-density lipoprotein, type 2 diabetes, hypertension, and cardiorespiratory fitness. After correcting for multiple tests, only body mass index and high-density lipoprotein showed significant associations. No causal effects were found between shift work and overweight, obesity, total cholesterol, low-density lipoprotein, fasting glucose, 2-h glucose, fasting insulin, coronary artery disease, myocardial infarction, heart failure, atrial fibrillation, or ischemic stroke. CONCLUSION: This MR study provides genetic evidence for a suggestive causal link between shift work and certain cardiometabolic outcomes. Our research may have the significance of providing insight into public hygiene to improve the understanding of shift work and cardiometabolic disease risk. Further experimental studies are needed to confirm our findings.

Effects of job demands, job resources, personal resources on night-shift alertness of ICU shift nurses: a cross­sectional survey study based on the job demands-resources model.

BACKGROUND: A positive work environment can enhance nursing safety and patient satisfaction while alleviating nurse stress. Conversely, a poor work environment can harm nurses' physical and mental health and compromise the quality of care, particularly in the high-intensity and shift-based setting of the ICU. OBJECTIVES: Based on the Job demands-resources (JD-R) model, this study examined the effects of job demands and job resources in the work environment, as well as personal resources, on the night-shift alertness of ICU shift nurses. METHODS: This cross-sectional correlational exploratory study, conducted from July to September 2022, recruited 291 ICU shift nurses from a hospital in Beijing, China. The Copenhagen Psychosocial Questionnaire (COPSOQ), the Self-resilience scale, the General Self-Efficacy Scale (GSES), and the Psychomotor Vigilance Task (PVT) were used to subjectively and objectively measure the job demands, job resources, personal resources, and night-shift alertness. SPSS 26.0 and Mplus 8.3 were used to analyze the data and construct the structural equation model. RESULTS: The night-shift reaction time was 251.0 ms (Median), indicating a relatively high level of alertness. Job demands were negatively correlated with both job resources (r=-0.570, P < 0.001) and personal resources (r=-0.462, P < 0.001), while a positive correlation existed between job resources and personal resources (r = 0.554, P < 0.001). The results show that increased job demands can lead to higher levels of nurse strain (ß = 0.955, P < 0.001), whereas job resources were found that it can decrease strain (ß=-0.477, P = 0.047). Adequate job resources can enhance motivation directly (ß = 0.874, P < 0.001), subsequently reducing reaction time (ß=-0.148, P = 0.044) and improving night-shift alertness among ICU shift nurses. CONCLUSION: Enhancing ICU shift nurses' work motivation through bolstering job resources can boost night-shift alertness. However, it is noteworthy that, in this study, neither strain nor individual resources significantly influenced nurses' night-shift alertness. This may be attributed to the complexity of the ICU environment and individual differences. Future research should explore the relationship between these factors and nurses' work alertness.

Night Shift Work Associates with All-Cause and Cause-Specific Mortality: A Large Prospective Cohort Study.

BACKGROUND: Health problems associated with shift work and night shift work are gaining increasing public attention. OBJECTIVE: To investigate the association between night shift work and the hazard of mortality. DESIGN: Prospective cohort study. PARTICIPANTS: A total of 283,579 individuals with paid employment or self-employment aged 37-73 years were included from the UK Biobank with a median follow-up period of 14.0 years. MAIN MEASURES: Participants were divided into day workers and shift workers, including the frequency of night shifts, to evaluate the association between baseline work schedules and all-cause and cause-specific mortality using the Cox proportional hazards model. Additionally, 75,760 participants with work histories were assessed for the association between average frequency and cumulative years of exposure to night shift work and all-cause and cause-specific mortality. KEY RESULTS: Compared with that of day workers, the adjusted hazard of all-cause mortality was increased by 12.0% (hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.07-1.18) in shift workers, particularly in those with no or rare night shifts (approximately 16.1%; HR, 1.16; 95% CI, 1.08-1.25) and those with irregular night shifts (approximately 9.2%; HR, 1.09; 95% CI, 1.00-1.19). Moreover, a non-linear relationship was identified between cumulative night shift years and all-cause and cause-specific mortality. Only individuals who worked night shifts for 20-30 years exhibited a substantially increased hazard of all-cause (HR, 1.52; 95% CI, 1.15-2.00) and cardiovascular disease (CVD; HR, 2.08; 95% CI, 1.16-3.71) mortality. CONCLUSIONS: Shift workers, particularly those with rare or irregular night shifts, exhibited an increased hazard of mortality. Additionally, participants who worked night shifts for 20-30 years exhibited a substantially increased hazard of all-cause and CVD mortality.

Effects and implementation of an intervention to improve sleep, fatigue and recovery among healthcare workers with night shifts: A pre- and post-test study.

BACKGROUND: Previous intervention studies among night workers mainly focused on single interventions and found inconclusive evidence for effectiveness. A comprehensive intervention approach that includes individual and environmental components has been argued as important. Gaining insight into contributing factors for the implementation of interventions for night workers and effectiveness is important to distinguish between theory and programme failure. OBJECTIVES: To evaluate the effects and implementation of the PerfectFit@Night intervention to improve sleep, fatigue and recovery of night workers in healthcare, using the RE-AIM framework, which assesses reach, effectiveness, adoption, implementation and maintenance of interventions. DESIGN: A prospective pre-post study design, with two measurements before and three and six months after the intervention. SETTING: Twelve different departments of a university hospital in the Netherlands. PARTICIPANTS: Healthcare workers working night shifts (n = 210). METHODS: PerfectFit@Night consisted of environmental (provision of a powernap bed and healthy food, and workshop healthy rostering) and individual elements (e-learning and sleep coaching) and was implemented for three months in a phased manner. Questionnaires, logbooks and interview data were used. Effects of the intervention on sleep, fatigue and recovery were evaluated with mixed-effects models, and implementation factors of reach, adoption, implementation and maintenance were evaluated. RESULTS: Night shift-related insomnia (-11 %-points, 95 % CI: -19 %, -4 % at three months), need for recovery (ß: -2.45, 95 % CI: -4.86, -0.03 at six months) and fatigue (OR: 0.46, 95 % CI: 0.25, 0.86 at six months) decreased significantly after the intervention. No changes were found for subjective sleep quality and sleep duration. Barriers and facilitators for implementation were identified for each intervention element at individual (e.g., dietary preferences), organisational (e.g., responsibilities at work) and workplace levels (e.g., location of power nap bed), and for the intervention itself (e.g., useful information in e-learning). Although satisfaction was high and continuation was preferred, embedding of the intervention in the daily routine was limited. Facilitators for future implementation include a positive attitude towards the intervention, clear guidelines regarding intervention elements, appointment of night workers as ambassadors, and suitable conditions in terms of work demands and for the intervention elements. CONCLUSIONS: The multi-faceted PerfectFit@Night intervention reduced insomnia, fatigue and need for recovery in night workers in healthcare. The most important facilitators to improve the implementation of PerfectFit@Night exist at the organisational level (e.g., positive attitude within the culture and suitable work demands). Combining effect and implementation evaluation is crucial to identify barriers and facilitators that hamper or enhance intervention effects. TRIAL REGISTRATION: The study was registered in the Netherlands Trial Register on 17 January 2021 (trial number NL9224).

Association and interaction effect of shift work and the risk for obstructive sleep apnea on diabetes mellitus in middle-aged Korean workers.

PURPOSE: To investigate the association of shift work and the risk for obstructive sleep apnea (OSA) with diabetes mellitus (DM), and the interaction effect of shift work and the risk for OSA on DM. METHODS: Data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2019-2021 were used. The participants were 3012 employees aged 40 to 59 years. Shift work was assessed using self-reporting questionnaires. The risk for OSA was assessed by STOP-BANG score. The distribution of demographic factors was calculated using the chi-square test. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression. An interaction effect between shift work and the risk for OSA on DM was evaluated using relative excess risk owing to interaction (RERI) and attributable proportion (AP) with 95% CIs. The synergic index (SI) was also calculated. RESULTS: Shift work and the risk for OSA were each significantly associated with DM. There was also a significant interaction effect between shift work and the risk for OSA on DM. The RERI was 0.543 (95% CI 0.205-1.361) and the AP was 0.230 (95% CI 0.145-0.342). The SI was 1.662 (95% CI 1.481-1.843). CONCLUSIONS: There was an association and a significant interaction effect of shift work and the risk for OSA on DM. The management of OSA in shift workers should be implemented to prevent DM.

Personalized sleep and nutritional strategies to combat adverse effects of night shift work: a controlled intervention protocol.

BACKGROUND: Working during the night interferes with the timing of normal daily activities and is associated with an increased risk of chronic diseases. Under controlled experimental conditions, interventions focusing on sleep and nutrition can mitigate the short-term adverse effects of shift work. However, it is unclear how these results translate to real-life, how they can be targeted to individual conditions, and how they relate to long-term health. Therefore, the current study aims to implement a personalized sleep and nutritional intervention among night shift workers in the field. METHODS: A non-blinded controlled intervention study is used, consisting of a run-in period, an intervention of 3 months, post-intervention measurements, and a follow-up after 12 months. Three study arms are included: sleep intervention, nutritional intervention, and control group (n = 25 each). Participants are healthy 18-60-year male night shift workers, with at least one year of experience in night shift work. Information from the run-in period will be used to personalize the interventions. The main outcomes are sleep measurements and continuous interstitial glucose levels. Furthermore, general health biomarkers and parameters will be determined to further evaluate effects on long-term health. DISCUSSION: This study aims to mitigate negative health consequences associated with night shift work by introducing two personalized preventive interventions. If proven effective, the personalized interventions may serve as practical solutions that can have a meaningful impact on the sustainable health and employability of night shift workers. This study will thereby contribute to the current need for high-quality data on preventative strategies for night shift work in a real-life context. TRIAL REGISTRATION: This trial has been registered under ClinicalTrials.gov Identifier NCT06147089. Registered 27 November 2023.

Humoral response to anti SARS-CoV2 vaccination at one and seven months is not different in shift workers and non-shift workers.

Since previous studies, mostly performed in healthy adults, show that sleep restriction around time of vaccination impairs antibody response and shift work affects sleep, aim of the study was to test the hypothesis that the antibody response to vaccination is impaired in shift workers, when compared to non-shift workers. Employees (n = 445; mean age 44 ± 11 years; 35 % men) of the Centro Cardiologico Monzino, IRCCS (Milan, Italy) were vaccinated against SARS-CoV2 in February 2021 with an mRNA-based vaccine. Antibody titers were assayed 1 and 7 months later. Differences between groups were assessed using ANOVA, after log-transformation of variables with right-skewed distribution. We report that the antibody titer was significantly higher in shift workers (33 % of employees) compared to non-shift workers at first assay [median (IQR): 2495 (1700; 4665) vs 2060 (1619; 2970) BAU/mL, p = 0.0123], as well as at the second one, and that this difference was abolished after adjustment for previous development of symptomatic COVID-19. Results were not affected by age or sex at birth. These results show that shift workers were able to mount an unimpaired antibody response to vaccination. Since vaccinations were performed during the pandemic urgency, our retrospective study has several limitations, nevertheless it underlines the need for large prospective, controlled studies on the effects of acute and chronic sleep restriction on response to vaccination in the general population and on the impact of shift work on immune response.