Coping with shift work-related circadian disruption: A mixed-methods case study on napping and caffeine use in Australian nurses and midwives

The risk of premature cardiac contractions (PAC/PVC) related to caffeine consumption among healthcare workers: A comprehensive review

Background and Aims

Premature atrial contractions (PACs) and premature ventricular contractions (PVCs) are ectopic heart rhythm disorders with implications for cardiovascular health. This study explores the relationship between caffeine consumption and the risk of PACs and PVCs, with a focus on healthcare workers, such as doctors, nurses, pharmacists, and midwives, who often rely on caffeine to combat fatigue, especially during night shifts.

Methods

A thorough review was conducted through PubMed, Scopus, Google Scholar, and Web of Science, utilizing a combination of MeSH terms and keywords. Studies examining the link between caffeine consumption and PACs and PVCs, particularly in healthcare workers, were included.

Results

We found that caffeine shows various effects based on dosage and can impact arrhythmia risk. Individuals working long shifts, including healthcare professionals, are prone to increased caffeine intake, leading to higher cardiovascular risk. To mitigate these risks, tailored guidelines for caffeine consumption, flexible shift scheduling, and mental health support services are recommended. Promoting caffeine alternatives within healthcare institutions can be beneficial.

Conclusion

Although caffeine may have potential benefits, its drawbacks, particularly concerning cardiovascular health, may surpass its advantages, especially when consumed in high doses. A multidisciplinary approach is crucial for healthcare workers' well-being and quality of patient care. Further research is required to refine and support these recommendations.

The Effect of Commencing Rotating Shift Work on Diet and Body Composition Changes in Graduate Paramedics: A Longitudinal Mixed Methods Study

Objectives: Diet quality often changes as shift workers adjust to atypical work schedules, however, limited research exists examining the early effects of starting rotating shift work on diet and body composition. This study explored dietary behavior changes occurring in graduate paramedics during the first year of exposure to rotating shift work, and investigated dietary intake, diet quality and anthropometric changes over two years. Methods: Participants from a graduate paramedic cohort in Melbourne, Australia were approached after two years of shift work for study inclusion. Using a mixed method study approach, the qualitative component comprised individual in-depth interviews to explore perceived dietary behavior changes experienced over the first year of shift work. Interview transcripts were thematically analyzed and guided by the COM-B model (capability, opportunity, motivation, and behavior) and theoretical domains framework (TDF). Diet quality and dietary intake were quantitatively assessed by the Australian Eating SurveyTM at baseline, one year, and two years, along with body weight, waist circumference, and body mass index (BMI) to monitor changes. Results: Eighteen participants were included in the study. From the interviews, participants reported: 1. food choices are driven by wanting to fit in with coworker food habits, 2. food choices and mealtimes are unpredictable and 3. paramedics try to make healthy food choices but give in to less healthy options. While daily energy intake and diet quality scores did not differ in the first two years of shift work, daily energy from takeaway foods significantly increased (mean difference (MD): 2.96% EI; 95% CI: 0.44 - 5.48; p = 0.017) and increases in weight (MD: 2.96 kg; 95% CI: 0.89-5.04; p = 0.003), BMI (MD: 1.07 kg/m2; 95% CI: 0.26 - 1.87; p = 0.006) and waist circumference (MD: 5.07 cm; 95% CI: 1.25-8.89; p = 0.006) were also evident at two years. Conclusions: This study contributes new information on dietary changes and the current early trajectory of unintentional weight gain and takeaway reliance occurring within a graduate paramedic cohort over two years of shift work. To reduce the unintended metabolic consequences commonly observed with rotating shift schedules, workplaces could improve access to healthier food options and enable behavioral support/education to address nutrition-related health risks.

Work-related psychosocial challenges and coping strategies among nursing workforce during the COVID-19 pandemic: a scoping review

BACKGROUND

Nurses and midwives have been stretched by the COVID-19 pandemic amidst the heroic roles they have played during the peak of the COVID-19 pandemic. Nurses stood tall among their peers in the healthcare industry saving lives. The pandemic has had a toll on nurses physically, psychologically, and socio-economically. The numerous deaths have traumatized nurses coupled with the fear of possible infection. Nurses have seen their colleagues and loved ones lose their lives to the pandemic, nevertheless, they still render care to patients no matter the circumstances. Due to that, it is imperative to ascertain the extent to which nurses who are much needed in healthcare delivery have been affected by this pandemic. This scoping review used Arksey and O'Malley's review methodology to investigate the nature of work-related psychosocial challenges nurses encountered during the peak of the pandemic, noting the major contributors to the challenges and the coping strategies used to address them.

METHODS

We performed a scoping review and searched for articles from five databases including PUBMED, CINAHL, SCOPUS, Google Scholar, and Grey literature from December 2019 to December 2021. A total of 7,334 articles were retrieved for the study but 45 met the inclusion criteria.

RESULTS

Work-related psychosocial challenges identified included stress, burnout (emotional exhaustion and depersonalization), Post-Traumatic Stress Disorder, depression, sleeplessness, and anxiety. Factors that accounted for the challenges were inadequate personal protective equipment (PPEs), discomfort using the PPEs, extreme workload, and fatigue. Nurses experienced job insecurity, business closure, and separation from family and loved ones, and these contributed to their challenges. Strategies used to deal with the challenges centred on emotion-focused and problem-focused coping.

CONCLUSIONS

The study recommends regular counselling and support for all nurses working at the frontline to help them better cope with the devastating effects of the pandemic so that they could build resilience towards future pandemics.

Shiftwork sleep disorder and associated factors among nurses working at public hospitals in Harari Regional state and Dire Dawa Administration, Eastern Ethiopia: a cross-sectional study

BACKGROUND

Shiftwork sleep disorder is one of the most common health-related effects of Shiftwork, particularly among healthcare workers. It is a chronic condition that is directly related to a person's work schedule. In Ethiopia, although a mental health strategy is in place, little attention is given to studies that focus on shiftwork sleep disorders among nurses. This study aimed to determine the magnitude of shiftwork sleep disorder and associated factors among nurses working at public hospitals in Harari Regional State and the Dire Dawa Administration.

METHODS

Institutional based cross-sectional study was conducted from June 1-30, 2021 among 392 nurses selected by a simple random sampling technique. A structured interviewer-guided self-administered questionnaire was used for data collection. The International Classification of Sleep Disorders 3rd edition (ICSD-3), Bargen Insomnia Scale (BIS) and Epworth Sleepiness Scale were used to assess shift-work sleep disorder. The data were entered into EpiData and exported to SPSS for analysis. Bivariable logistic regression was used to see the association between the outcome and the explanatory variables. Bivariate and Multivariate analyses were performed, and AOR with 95% CI was used to measure the strength of the association. Those variables with a p-values of < 0.05 were considered as statistically significant.

RESULTS

In this study, the magnitude of shiftwork sleep disorder among nurses was 30.4% (95% CI: 25.4-34.5). Being female (AOR = 2.4, 95% CI: 1.3, 4.2), working an average number of nights > 11 per month in the last 12 months (AOR = 2.5, 95% CI: 1.3, 3.8), and khat use in the last 12 months (AOR = 4.9, 95% CI: 2.9, 8.7) were significantly associated with the shiftwork sleep disorder.

CONCLUSIONS

The study revealed that about one-third of the nurses had a shiftwork sleep disorder implying a high burden of the problem among nurses in the study setting, which endangers nurses, patients, and the healthcare system. Being female, working an average number of nights > 11 per month in the last 12 months, and khat use showed statistically significantly associated with the shiftwork sleep disorder. Early detection of shiftwork sleep disorder, having a policy on khat use and considering rest/recovery while scheduling work time should be addressed to prevent shiftwork sleep disorder.

The relationship between the emergency nurses' sleep quality and the sleep quality of their spouses: A cross-sectional descriptive-analytical study

Background and Aims

Due to the heavy working shifts, emergency nurses may have to sleep at unusual times of the day, affecting their spouse's sleep. This study proposed to detect the relationship between the woman emergency nurse's sleep quality and the sleep quality of their spouses.

Methods

This cross-sectional descriptive-analytical study has lasted for 4 months since June 21, 2020. The study population was all women nurses working at a hospital emergency department. The data was collected by a demographic questionnaire and Pittsburgh sleep quality index (PSQI) for nurses and their spouses. The data were analyzed by descriptive and inferential statistics.

Results

The prevalence of sleep quality disorder among female emergency department nurses and their husbands was 82.7% and 80.6%, respectively. The mean sleep quality score of female nurses and their husbands was 8.46 ± 4.43 and 6.50 ± 2.52, respectively. A strong and positive correlation was found between the PSQI score of female nurses and their husbands (p < 0.001). The regression model showed that increasing the body mass index (BMI) of female emergency nurses can decrease their sleep quality. However, increasing the BMI of female emergency nurses' spouses and their work experience in the emergency department can improve their sleep quality.

Conclusion

The sleep quality of female emergency department nurses was directly correlated with their husbands' sleep quality. Therefore, the sleep quality of nurses working in the emergency departments and their spouses should be examined periodically.

Association of healthy beverage index with circadian rhythm and quality of sleep among overweight and obese women: a cross-sectional study

PURPOSE

Circadian rhythm is a behavioral, physiological, and molecular change with a cycle length of approximately 24 h. Changes to the circadian rhythm can result in sleep difficulty. The healthy beverage index (HBI) is a holistic concept for evaluating the quality of overall beverage intake and its association with health-related outcomes in nutritional epidemiological studies. This study aimed to assess the relationship of HBI with circadian rhythm and sleep quality among overweight/obese women.

METHODS

The current study was conducted among 208 overweight and obese women between 18-48 years in Tehran, Iran. We evaluated potential HBI with a valid food frequency questionnaire. Following standard procedures, trained personnel assessed anthropometric measures, blood samples, and other baseline characteristics. The Pittsburgh Sleep Quality Index and the morning-eveningness questionnaire were applied to evaluate sleep quality and circadian rhythm respectively.

RESULTS

The mean (SD) BMI for this study was 30.8 (4.2) kg/m². We observed that subjects in the least tertile had significantly high levels of triglyceride (p = 0.04) and low-density lipoprotein (p = 0.009). High-density lipoprotein was significantly different across the tertiles (p = 0.003). After adjusting for potential covariates, subjects in the second tertile of HBI had 5.07 odds of having the worst quality of sleep as compared to those in the third tertile, p < 0.05. We also observed a significant inverse association between the HBI and the "moderately evening type" participants (OR 0.86; 95% CI 0.68-0.99; p: 0.02) after adjusting for potential confounders.

CONCLUSION

Healthy beverage consumption may have the potential of improving sleep quality among overweight and obese subjects.

LEVEL OF EVIDENCE

Level IV, evidence obtained from a descriptive study.

Bowel Health in U.S. Shift Workers: Insights from a Cross-Sectional Study (NHANES)

Working outside of regular daytime hours is increasingly common in current societies and poses a substantial challenge to an individual’s biological rhythm. Disruptions of the gastrointestinal tract’s circadian rhythm and poor dietary choices subsequent to shiftwork may predispose the shift workforce to an increased risk of gastrointestinal disorders, including constipation, peptic ulcer disease, and erosive gastritis. We investigated bowel health in a US population of shift workers, using data from the National Health and Nutrition Examination Survey, and compared bowel movement (BM) frequency and defecation patterns between 2007 day workers and 458 shift workers (representing 55,305,037 US workers). Using bivariate and multivariate logistic regression techniques, our results suggested no association between shiftwork status and BM frequency, bowel leakage of gas, and stool consistency. Constipation prevalence was high but comparable in both groups (6.90% vs. 7.09%). The low fiber intake observed in both groups (15.07 vs. 16.75 g/day) could play a potential role here. The two groups did not differ with regard to other nutrients that may influence BM frequency and stool consistency (e.g., carbohydrate or caffeine intake). Additional studies including food group analyses and fecal biomarkers are warranted for a better understanding of GI health in shift workers.

Nurses' experiences and preferences around shift patterns: A scoping review

Objective

To explore the evidence on nurses’ experiences and preferences around shift patterns in the international literature.

Data sources

Electronic databases (CINHAL, MEDLINE and Scopus) were searched to identify primary studies up to April 2021.

Methods

Papers reporting qualitative or quantitative studies exploring the subjective experience and/or preferences of nurses around shift patterns were considered, with no restrictions on methods, date or setting. Key study features were extracted including setting, design and results. Findings were organised thematically by key features of shift work.

Results

30 relevant papers were published between 1993 and 2021. They contained mostly qualitative studies where nurses reflected on their experience and preferences around shift patterns. The studies reported on three major aspects of shift work: shift work per se (i.e. the mere fact of working shift), shift length, and time of shift. Across all three aspects of shift work, nurses strive to deliver high quality of care despite facing intense working conditions, experiencing physical and mental fatigue or exhaustion. Preference for or adaptation to a specific shift pattern is facilitated when nurses are consulted before its implementation or have a certain autonomy to self-roster. Days off work tend to mitigate the adverse effects of working (short, long, early or night) shifts. How shift work and patterns impact on experiences and preferences seems to also vary according to nurses’ personal characteristics and circumstances (e.g. age, caring responsibilities, years of experience).

Conclusions

Shift patterns are often organised in ways that are detrimental to nurses’ health and wellbeing, their job performance, and the patient care they provide. Further research should explore the extent to which nurses’ preferences are considered when choosing or being imposed shift work patterns. Research should also strive to better describe and address the constraints nurses face when it comes to choice around shift patterns.

Do Rotating Night Shifts Change Nurses' Nutritional Status? A Cross-Sectional Study

OBJECTIVE

Shift work disrupts circadian rhythms through environmental factors such as disruption of the light-dark and rest-activity cycle. This study aims to evaluate the nutritional status, circadian phenotype, sleep quality, and anthropometric measurements in nurses working in rotating night shifts.

METHOD

The study included 44 nurses working in rotating night shifts. Physical activity records for 4 days and 24-hour dietary recalls for 7 days were taken. To evaluate the circadian phenotypes and sleep quality, the Morningness-Eveningness Questionnaire and the Pittsburg Sleep Quality Index were used, respectively.

RESULTS

Most nurses were evening chronotype and had poor sleep quality. Shift work was associated with higher daily energy intake and lower total daily energy expenditure (p < 0.05). On the night shifts, while fiber-rich foods such as beans and fruit consumption decrease, the consumption of fats, sweets, and cereals increases. While carbohydrates, total fat, and cholesterol intake were higher in only women on the night shift (p < 0.05), saturated fat and calcium intake were higher in all nurses (p < 0.05). While the water intake of the nurses was lower on the night shift (p < 0.05), tea intake was higher in women (p < 0.05). A correlation was found between total shift work duration, body mass index (r = 0.525), waist circumference (r = 0.577), waist-height ratio (r = 0.584), and body fat percentage (r = 0.513) (p < 0.001).

CONCLUSIONS

Nurses should be encouraged to ensure adequate water intake and to make healthy food choices during the night shift to maintain health and work performance.

The Health Behaviour of German Outpatient Caregivers in Relation to the COVID-19 Pandemic: A Mixed-Methods Study

The COVID-19 pandemic has affected outpatient caregivers in a particular way. While the German population becomes increasingly older, the number of people in need of care has also increased. The health and, thus, the health behaviour of employees in the outpatient care become relevant to maintain working capacity and performance in the long term. The aims of the study were (1) to examine the health behaviour and (2) to explore pandemic-related perceived change of health behaviour among outpatient caregivers during the COVID-19 pandemic. In a mixed-methods study, 15 problem-centred interviews and a web-based cross-sectional survey (N = 171) were conducted with outpatient caregivers working in Northern Germany. Interviewees reported partially poorer eating behaviour, higher coffee consumption, lower physical activity, skipping breaks more often and less sleep duration and quality during the pandemic. Some quantitative findings indicate the same tendencies. A majority of participants were smokers and reported higher stress perception due to the pandemic. Preventive behaviour, such as wearing PPE or hand hygiene, was increased among interviewees compared to the pre-pandemic period. Our findings indicate that the COVID-19 pandemic could negatively affect outpatient caregivers' health behaviour, e.g., eating/drinking behaviour and physical activity. Therefore, employers in outpatient care should develop workplace health promotion measures to support their employees in conducting more health-promoting behaviours during the COVID-19 pandemic.

The Health Behaviour of German Outpatient Caregivers in Relation to Their Working Conditions: A Qualitative Study

Ongoing demographic change is leading to an increasingly older society and a rising proportion of people in need of care in the German population. Therefore, the professional group of outpatient caregivers is highly relevant. Their work is characterised not only by interacting with patients in a mobile setting but also by working in shifts. Health behaviour under these specific working conditions is crucial for ensuring long-term work ability and performance. Little is known about the health behaviour of German outpatient caregivers and its potential impact on their work. The aims of the study were (1) to examine health behavioural patterns (nutrition, exercise, smoking, regeneration) of outpatient caregivers, (2) to illuminate their personal health-promoting behaviours, and (3) to identify potential work-related factors influencing their health behaviour. Fifteen problem-centred interviews were conducted with outpatient caregivers working in Northern Germany in the period January-April 2020. Interviews were analysed by using qualitative content analysis. Outpatient caregivers reported improvable nutrition and hydration, with simultaneous high coffee consumption, low physical activity, poor regeneration (breaks and sleep quality), and good personal health-promoting behaviour (e.g., back-friendly habits), although the majority were smokers. Barriers to the implementation of health-promoting behaviours were a high perception of stress due to increased workload and time pressure, while aids to better health-promoting behaviour were described as being social support and personal resources. The respondents perceived their working conditions as potentially influencing their health behaviour. On the basis of their descriptions, various practice-relevant strategies were derived. The data explore a potential need for outpatient care services to develop interventions on behavioural and structural levels that can help create healthier working conditions for their employees so these caregivers can adopt better health behaviours.

Demographics, sleep, and daily patterns of caffeine intake of shift workers in a nationally representative sample of the US adult population

STUDY OBJECTIVE

Caffeine is the most widely consumed stimulant in the world, and sociodemographic factors including occupation are associated with intake. Shift work, required in various occupations, is associated with poor sleep, inadequate diet, and adverse health effects. Using a large nationally representative database, demographics, sleep, and caffeine intake of US adults working various shifts were assessed.

METHODS

The 24-hour dietary recall data from NHANES 2005-2010 (N = 8,500) were used to estimate caffeine intake from foods and beverages. Work shifts were self-reported as follows: regular day shift; evening shift; night shift; rotating shift; or other shift. Regression analyses assessed associations of shift work with caffeine intake after adjustment for sociodemographic factors.

RESULTS

Approximately 74% of employed adults were day-shift workers and 26% were nonday-shift workers. Night-shift workers slept for 6.25 ± 0.09 hours per day, somewhat less than day-shift workers who only slept 6.83 ± 0.02 hours (p < .0001). Mean 24-hour weekday caffeine intake of evening-, night-, and rotating-shift workers (217 ± 23, 184 ± 19, and 206 ± 15 mg, respectively) was similar (p > .3) to day-shift workers (203 ± 5 mg). Regardless of work schedule, individuals consumed the most caffeine during morning hours. Evening- and night-shift workers reported consuming 36%-46% less caffeine during their work hours and 72%-169% more during nonwork hours than day-shift workers (p < .01).

CONCLUSIONS

Total daily caffeine intake of shift workers is similar to nonshift workers; most caffeine is consumed in the morning regardless of shift. Because shift workers consume less caffeine during regular work hours and more during nonwork hours than day workers, they may be using caffeine to, in part, optimize off-duty alertness.

Sleep complaints in former and current night shift workers: findings from two cross-sectional studies in Austria

Sleep impairment is highly prevalent in night shift workers, but evidence on the association of former night shift work (NSW) and its metrics (duration and frequency) in relation to sleep complaints is lacking. We evaluated the association of former and current NSW with chronic insomnia or circadian rhythm sleep disorder in a sample of the general worker (GW) population and in hospital workers (HW) in Austria. Information on sleep, NSW history, sociodemographic, and lifestyle factors was collected through an online cross-sectional survey in a representative sample of GW (N= 1,004) and a sample of HW (N= 799) between 2017 and 2019. Multi-variable adjusted logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for various measures of sleep (including chronic insomnia, daytime sleepiness, sleep duration, napping habits) and doctor-diagnosed chronic insomnia across NSW exposure (never night shift work; ever; ever/former; ever/current) and related metrics (cumulative duration, average frequency), compared to never NSW. Effect modification by chronotype and daytime napping was investigated. Former NSW was associated with higher odds of chronic insomnia in both samples (GW: OR = 2.28, 95% CI = 1.07-4.83; HW: OR = 1.17, 95% CI = 0.60-2.27). Chronic insomnia odds tended to increase among current night shift workers (HW: OR = 1.50, 95% CI = 0.79-2.83), compared to day workers. Higher NSW frequency (shifts/month) was associated with higher chronic insomnia odds in former night shift workers in both samples (GW: OR_{per shift/month} = 1.06, 95% CI = 1.00-1.12; HW: OR_{per shift/month} = 1.12, 95% CI = 1.00-1.25). Former NSW was also associated with increased daytime sleepiness among GW (OR = 2.26, 95% CI 1.28-3.99). Associations were more pronounced among early chronotypes and participants who reported no daytime naps. Our results suggest that NSW is associated with chronic insomnia even in the years after cessation of involvement in working it.

Caffeine and high energy drink use and knowledge by nurses in three countries

AIM

The purpose of this study was to examine nurses' use and knowledge of caffeine and high energy drinks (HED) in three countries.

METHODS

Nurses in each country completed a survey on caffeine and HED use and knowledge.

RESULTS

In a sample of 182 nurses, caffeine use was high with 92% of nurses in Korea, 90.8% in Italy and 88.1% in the United States (US) having at least one cup of coffee a day while 64% of Koreans and 11.9% of those in the US had at least one HED per day. In Korea 68% of nurses (Italy 63.1% and 35.8% US) had at least one cup of caffeinated tea per day. Most agreed there is a need to educate nurses about HED, which contain high amounts of caffeine. Over half of nurses in Korea (58%) and the US (56.7%) said their colleagues consume HED at work.

CONCLUSION

Findings of this study indicate many nurses are consuming caffeine at work and there is a need for education. It is unclear how caffeine affects nurses' clinical performance, which raises the issue of patient safety. Further research is needed regarding safe amounts of caffeine while nurses are on the job as well as an understanding of how HED additives may affect the well-being and clinical care of nurses.

A Solution to After-Hours Fatigue and Surgical Backlog

After-hours surgery represents a novel solution that can effectively combat surgical fatigue of care teams in addition to addressing the high volume of surgical backlog associated with the repercussions of the COVID-19 pandemic. This commentary seeks to rationalize how successful employment of a dedicated after-hours surgical team and protocol has tremendous potential for increased efficiency while maintaining good surgical outcomes in patients.

Vigilance and sleepiness in nurses working 12-hr shifts and their coping strategies

AIM

To describe the progression of vigilance and sleepiness over the shift and the coping strategies of nurses working 12-hr day or night shifts.

BACKGROUND

The spread of 12-hr shift work in nursing raises the question of whether sufficient vigilance can be maintained to ensure quality of care.

METHOD

18 nurses working 12-hr shifts filled out a Karolinska Sleepiness Scale questionnaire and a Brief Psychomotor Vigilance Test, at the beginning of the shift and then every 3 hr. Coping strategies and quality of care were assessed on self-administered questionnaires, filled out at 3 hr, 6 hr, 9 hr and 12 hr after the start of the shift.

RESULTS

The present investigation did not show significantly excessive sleepiness or vigilance impairment or poor self-perception of quality of work during 12-hr nursing work shifts, although Psychomotor Vigilance Test results gradually deteriorated slightly over duty time (from start to end of shift). Certain coping strategies were preferred such as 'having a nap' later in the night shift.

CONCLUSION

Attention needs to be paid to the health status of nurses working 12-hr shifts, with regular medical monitoring by the occupational health service.

IMPLICATIONS FOR NURSING MANAGEMENT

Coping strategies to maintain sufficient vigilance to ensure quality of care should be facilitated.

The dynamic relationship between daily caffeine intake and sleep duration in middle-aged and older adults

The effect of caffeine on sleep has been well documented. However, most studies examined this relationship in laboratories or used a cross-sectional design analysing between-person differences. This study investigated the within-person relationship between caffeine intake and sleep duration at home. In a national database, 377 participants (aged 35-85 years) completed a 7-day diary study. Sleep duration was measured by Actigraphy and caffeine intake was self-reported in sleep logs. Three analytic strategies were used. The average sleep duration and the average caffeine intake were not significantly correlated. Multilevel regressions using daytime caffeine intake to predict night-time sleep, and using night-time sleep to predict next day caffeine intake, also did not detect any significant effect. Then dynamical systems analysis was performed, where the daily change rate and change tendency of caffeine and sleep were estimated, and the relationship among these momentums was examined. Results revealed a significant effect of sleep duration on the change tendency of caffeine use: a shorter sleep duration predicted a stronger tendency to consume caffeine, and this phenomenon was only found in middle-aged adults (aged 35-55 years) not in older adults (aged 55+). This study did not detect any effect of daily caffeine intake on sleep duration, implying that habitual use of caffeine in real life may not coincide with laboratory findings, and that using caffeine to compensate for sleep loss is the habit of middle-aged adults, not the elderly. The advantage of using a dynamic approach to analyse interrelated processes with uncertain time lags is also highlighted.

How Do Nurses Cope with Shift Work? A Qualitative Analysis of Open-Ended Responses from a Survey of Nurses

Nurses are frequently required to engage in shift work given the 24/7 nature of modern healthcare provision. Despite the health and wellbeing costs associated with shift work, little is known about the types of coping strategies employed by nurses. It may be important for nurses to adopt strategies to cope with shift work in order to prevent burnout, maintain wellbeing, and ensure high quality care to patients. This paper explores common strategies employed by nurses to cope with shift work. A workforce survey was completed by 449 shift working nurses that were recruited from a major metropolitan health service in Melbourne, Australia. Responses to open-ended questions about coping strategies were analysed using the framework approach to thematic analysis. Four interconnected main themes emerged from the data: (i) health practices, (ii) social and leisure, (iii) cognitive coping strategies, and (iv) work-related coping strategies. Although a range of coping strategies were identified, sleep difficulties often hindered the effective use of coping strategies, potentially exacerbating poor health outcomes. Findings suggest that in addition to improving nurses' abilities to employ effective coping strategies on an individual level, workplaces also play an important role in facilitating nurses' wellbeing.

Temporal pattern of eating in night shift workers

Understanding shift workers dietary intake patterns may inform interventions targeted at lowering chronic disease risk. This study examined the temporal distribution of food intake as shift workers rotate between night shifts, day shift and/or days off to identify differences in energy intake, eating frequency, and adherence to dietary guidelines by shift type (night shift vs. day). Night shift (NS) workers completed a four-day food diary that included a minimum of two night shifts and one-day shift (DS)/day off (DO), recording all food, beverages and time of consumption. Comparisons were between shift types, using ANOVA for continuous data and generalized estimating equations for count data, data reported as mean (SE). When comparing NS and DSDO, there were no differences in energy intake (24 h) (8853 (702) vs. 9041 (605) kJ, n = 22) or adherence to dietary guidelines. There was no difference between the number of eating occasions on NS and DSDO (5.6(0.3) vs 5.1(0.6) occasions) but less energy per eating occasion at night (1661(125) vs 1933(159) kJ). When working NS compared with DSDO there was higher total sugar (%E, 19.1(2.0) vs 15.0(2.4)) and lower saturated fat (%E, 13.8(1.2) vs 15.7(1.3)). Further, DSDO were characterized by a pattern of three main meals and a prolonged fasting period. It is important to determine if reducing eating occasions and providing opportunities for fasting improves metabolic health.

23rd International Symposium on Shiftwork and Working Time: Towards a Global Consensus

The Working Time Society (WTS), and the International Commission on Occupational Health (ICOH) Scientific Committee on Shiftwork and Working Time, are twin organisations focused on conducting research, and informing practice, regarding the impact of work hours in general, and shiftwork in particular, on the efficiency, productivity, safety, well-being, health, and biological rhythms, of employees. Every 2-3 years since 1969, the WTS and ICOH have conducted a series of international symposia in Europe, Asia, Australia, North America, and South America. The purpose of these symposia is to provide a forum for the exchange of knowledge, and the discussion of contested issues, with researchers, employee representatives, regulators, and employers. The most recent symposium in this series - the 23rd International Symposium on Shiftwork and Working Time, entitled "Toward a Global Consensus" - was held on 19-23 June 2017, at Yulara, Australia, near Uluru. Since 2004, Chronobiology International has released a special issue after each symposium, and that tradition continues with a special issue that includes 17 contributions based on a selection of the 128 papers that were presented at the most recent symposium. Here, we provide an overview of the papers that comprise the special issue, and we briefly comment on the implications of the findings for shiftworkers and their employers.

Burnout, Sleep, and Sleepiness during Day and Night Shifts in Transition from 8- to 12-Hour Shift Rosters among Airline Ground Crew Managers

Organizational changes in shift scheduling provide rare opportunities for field studies aimed at investigating the effects of such changes on health and wellbeing. We studied the effects of a transition from 8-hour (8-h) to 12-hour (12-h) shift rosters in 39 airline ground crew managers on burnout, sleep quality, and sleepiness. Assessments were collected during the 8-h and were repeated three months after the transition to 12-h shift rosters. These assessments included the Shirom-Melamed Burnout Measure (SMBM), the Pittsburgh Sleep Quality Index (PSQI), actigraphy, the Karolinska Sleepiness Scale (KSS) completed hourly during one day and two night shifts, and caffeine intake. Findings demonstrated lower burnout, improved sleep quality, improved quality of naps, and increased afternoon sleepiness during the 12-h day shift. Napping was reported during 12-h night shifts by 36% of the sample. In nappers, increased night shift sleepiness was associated with increased caffeine intake on 8- and 12-h shifts. In non-nappers, increased night shift sleepiness was associated with decreased caffeine intake on the 8-h shift only. Change in shift length affects other structural and behavioral parameters in the workplace, making it challenging to isolate distinct characteristics of the two rosters and their relative effects on study outcomes. Individual differences in adaptation to shiftwork may also play a role.

Self-regulation and social behavior during sleep deprivation

An emerging literature is specifically focusing on the effects of sleep deprivation on aspects of social functioning and underlying neural changes. Two critical facets of social behavior emerge that are negatively impacted by sleep deprivation-self-regulation, which includes behavioral and emotional regulation, and social monitoring, which includes perceiving and interpreting cues relating to self and others. Sleep deprived individuals performing tasks with social components show altered brain activity in areas of the prefrontal cortex implicated in self-control, inhibition, evaluation, and decision-making, in proximity to mesocorticolimbic pathways to reward and emotional processing areas. These cognitive changes lead to increased reward seeking and behaviors that promote negative health outcomes (such as increased consumption of indulgence foods). These changes also lead to emotional disinhibition and increased responses to negative stimuli, leading to reductions in trust, empathy, and humor. Concomitant attentional instability leads to impaired social information processing, impairing individual and team performance and increasing likelihood of error, incident, and injury. Together, changes to reward seeking, the foundational components of social interaction, and interpretation of social cues, can result in unpleasant or deviant behavior. These behaviors are perceived and negatively responded to by others, leading to a cycle of conflict and withdrawal. Further studies are necessary and timely. Educational and behavioral interventions are required to reduce health-damaging behaviors, and to reduce emotionally-laden negative interpretation of sleep-deprived exchanges. This may assist with health, and with team cohesion (and improved performance and safety) in the workplace and the home.