Mothers with depressed mood: help-seeking from husbands and child-rearing behaviors.

BACKGROUND: Mothers with depressed mood tend not to seek help or support from others. Yet, there is no research providing a detailed examination of the processes that mothers with depressed mood undergo while seeking child-rearing support from their husbands. This study aimed to clarify the processes that mothers with depressed mood go through in seeking child-rearing support from their husbands and performing child-rearing duties. METHODS: The participants were 10 mothers living in Japan who had given birth within the past three years and were suspected of having depression after screening using the Edinburgh Postnatal Depression Scale. Semi-structured interview data were analyzed based on the grounded theory. RESULTS: The responses revealed that the mothers felt as though they had insufficient time for themselves, which impelled them to seek support from their husbands, consequently leading them to conclude either that child-rearing and housework are difficult or that child-rearing can be managed some way or another. CONCLUSION: When the husbands fully cooperated in child-rearing or demonstrated their willingness to cooperate in child-rearing, despite difficulty, the wives accepted their child-rearing support. On the other hand, if the husbands did not recognize their wives' efforts, the wives did not accept their support, even if they had helped with child-rearing. In this way, the wives re-evaluated their relationship with the husbands based on their husbands' attitudes toward child-rearing.

Experiences and perceptions of people living with schizophrenia in Japan: A qualitative study.

This descriptive study used a qualitative inductive approach to investigate the subjective experiences and perceptions of people with schizophrenia living in the community during times of difficulty and how they coped. We conducted semi-structured interviews with nine community-dwelling people with schizophrenia and used the KJ method developed by Kawakita Jiro to structure the data obtained. We identified 10 symbols with his method: bewilderment at the onset; helplessness and longing for death; solitude linked to death; precarious daily life; relationships at risk; fear of being stigmatized; pillars of emotional support; will to overcome; hope to never give up; and living with the illness. The results suggest that community mental health nurses should provide support so their patients can continue to have pillars of emotional support and the will to overcome difficulties, as well as continue to use their coping methods, even when experiencing many difficulties. It is important that nurses understand and share in their patients' difficult experiences and hopes when providing support toward their recovery.

The role of online ethics consultation on mental health.

BACKGROUND: Nurses experience moral distress when they cannot do what they believe is right or when they must do what they believe is wrong. Given the limited mechanisms for managing ethical issues for nurses in Japan, an Online Ethics Consultation on mental health (OEC) was established open to anyone seeking anonymous consultation on mental health practice. RESEARCH OBJECTIVE: To report the establishment of the Online Ethics Consultation and describe and evaluate its effectiveness. ETHICAL CONSIDERATIONS: The research was conducted in accordance with the Declaration of Helsinki. RESEARCH DESIGN: This evaluation describes the outcomes of 5 years of operation of the Online Ethics Consultation on mental health in Japan. PARTICIPANTS: The Online Ethics Consultation received 12 emails requesting consultation. Consultees included mental health nurses, psychiatrists, and service users. FINDINGS: The most common questions directed to the service were about seclusion and physical restraint. Response time from receipt of email to sending a reply was between 1 and 14 days. Despite the disappointing number of consultations, feedback has been positive. DISCUSSION: The Online Ethics Consultation was established to assist morally sensitive nurses in resolving their ethical problems through provision of unbiased and encouraging advice. Mental health care in Japan has been less than ideal: long-term social hospitalization, seclusion, and restraint are common practices that often lead to moral distress in nurses and the questions received reflected this. The head of the Online Ethics Consultation sent a supportive, facilitative response summarizing the opinions of several consultants. CONCLUSION: This study provides key information for the establishment of an online ethics resource the adoption of which has the potential to improve the experience of nurses, allied health and clients of mental health services. This paper has implications for services concerned with improving patient care, managing nurses' moral distress, building ethics into decision-making.

Analysis of the emotional experiences of Japanese Alcoholics Anonymous members striving for sobriety.

BACKGROUND: Japan's tolerance of alcohol consumption and intoxication pose extreme difficulties for community-dwelling alcoholics who wish to abstain from alcohol and maintain sobriety. Emotional problems triggered in daily life can easily lead to relapse, especially after abstinence. Alcoholics Anonymous places great emphasis on dealing with attendees' emotional experiences. However, the specific nature of this support is not well understood. Therefore, this study aimed to elucidate the emotional experiences of AA members who strive for sobriety while attending AA and to identify suggestions for new methods of support. METHODS: The present study employed an interview method. Data were analyzed using the KJ Method, which was developed by Japanese cultural anthropologist Jiro Kawakita. Study participants were 36 men chosen from AA groups in the Kanto and Kyushu regions of Japan. RESULTS: Long-term abstinence was achieved through the following process: 1) gaining objectivity, 2) striving to maintain an attitude of acceptance, and 3) remaining devoted to discipline for one's goals, thereby 4) recovering one's contradictory self. This was an unending process that unfolded as the individual tasks affected each other. To facilitate this process, AA members dealt with risk cues that destabilized post-cessation emotional balance while making daily efforts to regulate their own emotions. CONCLUSIONS: To maintain sobriety, AA members strove to regulate their emotions. By doing so, they experienced personal growth and attained a life in which they did not require alcohol (i.e., sobriety). The present study indicated that Japanese nursing and health care workers should be willing to learn from AA members, such as by understanding the 12-step culture. The data also suggest the need to create environments conducive to AA activities, from which many alcoholics derive emotional support.

Impact of moral sensitivity on moral distress among psychiatric nurses.

BACKGROUND: Moral distress occurs when one knows the right thing to do, but institutional constraints make it nearly impossible to pursue the right course of action. Moral distress was found to cause negative feelings, burnout, and/or resignation. Not only external factors such as lack of staff but also internal ones affect moral distress. Moral sensitivity, which is thought of as an advantage of nurses, could effect moral distress, as nurses being unaware of existing ethical problems must feel little distress. OBJECTIVES: To examine the impact of moral sensitivity on moral distress among psychiatric nurses, and affirm the hypothesis that nurses with higher moral sensitivity will suffer moral distress more than nurses with less moral sensitivity in two different samples. ETHICAL CONSIDERATION: The study obtained ethical approval from the Research Ethics Committee of the Faculty of Medicine at Mie University (# 1111, 20.4.2010), and by the Turku University Ethics Board (29.5.2012). Permissions to undertake the study was obtained from the in two hospital districts and in one city (§ 48/4.10.2012, § 63/4.9.2012, 51/2012 27.8.2012). Informed consent was not formally obtained, because the questionnaire was anonymously reported by the participants who volunteered to answer. The participants responded voluntarily and anonymously. METHODS: An anonymous questionnaire containing the Revised Moral Sensitivity Questionnaire and the Moral Distress Scale for Psychiatric nurses was conducted to 997 nurses in 12 hospitals in Japan, and 974 nurses in 10 hospitals in Finland after obtaining of approval by research ethics committees. Data were analyzed using a multi-group structural equation model analysis. FINDINGS: A set of analyses imply that the association of moral sensitivity with moral distress is significant and similar between Japan and Finland, whereas the factor structures of moral sensitivity and moral distress may be partially different. DISCUSSION: The result of this study may indicate that nurses with high moral sensitivity can sense and identify moral problems, but not resolve them. Therefore, supporting nurses to solve ethical problems, not benumbing them, can be important for better nursing care and prevention of nurses' resignation. CONCLUSION: Moral sensitivity and moral distress were positively correlated among psychiatric nurses in both Japan and Finland, although the participating nurses from the two countries were different in qualification, age, and cultural background. Nurses with high moral sensitivity suffer from moral distress.

Job Stress Factors Affect Workplace Resignation and Burnout among Japanese Rural Physicians.

Shortage of healthcare workers is a global problem. It is important to clarify factors, including job stress, that influence workplace resignation and factors that cause burnout among rural physicians. The study was designed as a cross-sectional questionnaire survey. We sent questionnaires to town or village hospitals and clinics (n = 1,898) in Hokkaido, Tohoku, Shikoku, and Kyushu and Okinawa. The number of participants was 509. Of these 7.7% were female and 21.6% were < 50 years. Internal or general medicine physicians were asked about personal and job factors, job stress based on the demand-control-support model, intention to resign from current position, and burnout evaluated using the Maslach Burnout Inventory-General Survey. Overall, 10.4% of the participants intended to resign, and 21.8% was defined as burnout positive. In the multivariate logistic regression analysis, dissatisfaction with income (OR, 3.63; 95% CI, 1.63-8.10), having one's hometown in another town or village in the same prefecture (OR, 3.53; 95% CI, 1.18-10.62) were significantly related to intention to resign, while high job control (OR, 0.72; 95% CI, 0.58-0.88) had a significantly protective effect. In the multivariate analysis, high job demand (OR, 1.48; 95% CI, 1.28-1.72) was significantly related to burnout, and high job control (OR, 0.66; 95% CI, 0.55-0.78) and high support from co-workers (OR 0.88, 95% CI, 0.78-1.00) had a significantly protective effect. Improving job stress factors, especially job control, and taking into consideration physicians' hometown and income may be important factors to prevent resignation from a current position and burnout among Japanese rural physicians.

Development of the salt-reduction and efficacy-maintenance program in Indonesia.

We conducted a randomized, controlled trial to examine the effects of a salt-reduction and efficacy-maintenance program on the improvement and maintenance of self-care and self-efficacy in reducing the salt intake of older people with high blood pressure. A total of 51 participants with hypertension/prehypertension in Indonesia were randomly assigned to a control group or one of two intervention groups: salt-reduction training or salt-reduction and efficacy-maintenance. The salt-reduction and efficacy-maintenance group received educational training and a maintenance meeting; the participants' knowledge, attitudes, self-care practices, and self-efficacy significantly improved after training and were maintained after the maintenance meeting. Participants in the salt-reduction training group showed significant effects for the same variables; however, their food salt concentrations rebounded after the maintenance meeting. No significant improvement was found in the control group. The salt-reduction and efficacy-maintenance group participants reported positive effects of salt reduction and different practices based on who prepared their meals. The salt-reduction and efficacy-maintenance group program was effective in improving and maintaining knowledge, attitudes, and self-efficacy of salt-reduction practices and could be applied with community-dwelling older people with high blood pressure.

[Relationships between ignoring instructions and response bias when completing questionnaires].

Certain participants are insincere, or careless when they respond to questionnaires. To identify such participants, we included three items in a questionnaire that instructed participants to choose a particular response category. Nurses (N = 1,000) responded to this questionnaire in a Web survey. One-hundred-twenty participants failed to follow the instructions for at least one item (non-followers). Analyzing their responses indicated the following: (a) non-followers were more likely to give identical, or midpoint responses; (b) the correlations between their responses to regular and reversed items were low or positive, and their responses to scales containing reversed items tended to show lower internal consistency; and finally, (c) the mean scores of non-followers were closer to the midpoint of the scale, regardless of whether the scale included reversed items. One reason that including reversed items lead to lower internal consistency could be because participants occasionally missed responding to these items. However, the results suggested that non-followers were not diligent in responding to regular items, and merely deleting reversed items from scales will be insufficient to ensure accurate results.

How nursing students' perceptions of people with psychiatric disabilities change when using the strengths model during practicums: A qualitative research study.

BACKGROUND: The Strengths Model, a framework grounded in the belief that everyone has an inherent capability to cope with challenges, is designed to support the hopes and aspirations of people with psychiatric disabilities, guiding them toward their desired self-image. The model originally gained attention in the field of social welfare and has since become popular in the field of community mental health. There is an increasing demand for nurses to understand and implement this model in the support they provide. OBJECTIVES: To clarify how implementation of the Strengths Model in nurse education impacts students' perceptions of their clients with psychiatric disabilities. DESIGN: Qualitative descriptive study informed by Grounded Theory. SETTING: Public university nursing practicum. PARTICIPANTS: Sixteen fourth-year students undertaking a practicum using the Strengths Model. METHODS: Semi-structured interviews. RESULTS: The core concept identified was that people with psychiatric disabilities uncover their own inherent strengths. Students began their engagement by listening to clients' dreams and goals. Then, three processes were identified that led to the outcome of students seeing clients in terms of their limitations, while one process was identified that led to the alternate desirable outcome of students developing a sense of respect for clients. CONCLUSIONS: These findings indicate that the process leading to students developing a sense of respect for clients with psychiatric disabilities involved three interrelated factors: students listening to clients' dreams and goals, both parties working together to discover the clients' dreams, and clients uncovering their own inherent strengths and then leveraging them. Incorporating the Strengths Model, which takes a person-centric approach to support the agency of people with psychiatric disabilities, into nurse education has the potential to foster healthcare professionals who respect people with psychiatric disabilities, see them on an equal footing, and consider themselves partners in facilitating the recovery journey.

Efficacy of a group-based parenting program on stress and self-efficacy among Japanese mothers: a quasi-experimental study.

Early child development and the impact of parenting on later life are of global concern. The rise in child abuse and maltreatment in Japan suggests that measures to increase self-efficacy and reduce stress would benefit Japanese parents. In this study, we explored if Japanese parents attending a 123Magic parenting program reported reduced stress and enhanced self-efficacy. Questionnaire data were collected from 49 mothers attending a parenting program conducted in public nursery schools in one prefecture in Japan. There were significant changes in parenting self-efficacy scores (P < 0.001) and parenting stress scores (P < 0.01). Focus groups with 16 parents also found that there were benefits to parents in terms of increased confidence and less stress. The findings provide support for the role of public health nurses in delivering group-based parenting support in Japan.

Stressor Scale for Clinical Research Coordinators: development and psychometric testing.

AIM: This article is a report of the development and psychometric testing of the Stressor Scale for Clinical Research Coordinators. BACKGROUND: Job stress is viewed as a situation where working conditions interact with individual worker characteristics and result in disruption of psychological or physiological homeostasis. Clinical research coordinators, also known as research nurses, are professionals who play a central role in clinical trials. They face various problems associated with their responsibilities; however, few studies have reported on their stress. To manage their stress, it is necessary to identify the sources of stress (i.e. stressors). METHOD: The 56-item preliminary instrument was developed based on literature review and expert discussions. A total of 589 clinical research coordinators in 186 hospitals in Japan were surveyed in 2011. Statistical analyses on construct and concurrent validity, internal consistency, and test-retest reliability were performed. RESULTS: A six-factor solution with 23 items was selected using exploratory factor analysis: 'quantitative workload', 'conflict with investigators', 'ambiguity of work', 'conflict with other clinical research coordinators and with supervisors', 'demands from an affiliate other than the hospital', and 'difficulty in caring for trial participants'. Confirmatory factor analysis affirmed construct validity, with a demonstrated acceptable fit between the factor structure and the observed data. All factors had significant correlations with burnout and psychological distress, which indicated acceptable concurrent validity. Cronbach's alpha coefficients ranged from 0·73-0·82. Intra-class correlation coefficients indicated almost satisfactory test- retest reliability. CONCLUSION: Our new instrument has acceptable validity and reliability for evaluating job stressors for clinical research coordinators.

Resident Burnout and Work Environment.

Objective We examined the prevalence of burnout among resident doctors and its relationship with specific stressors. Method We conducted a nationwide, online, cross-sectional survey in Japan with 604 resident doctors in 2018-2019. Materials Participants completed the Maslach Burnout Inventory-General Survey to evaluate burnout and provided details of their individual factors and working environmental factors. Chi-square tests and t-tests were conducted for categorical and continuous variables, respectively. The association between burnout and resident-reported causes of stress, ways of coping with stress, number of times patient-safety incidents were likely to occur, and individuals who provide support when in trouble was analyzed using logistic regression analyses after controlling for confounding variables. Results A total of 28% met the burnout criteria, 12.2% were exhausted, 2.8% were depressed, and 56.9% were healthy. After adjusting for sex, postgraduate years, type of residency program, marital status, number of inpatients under residents' care, number of working hours, number of night shifts, number of days off, and resident-reported causes of stress - excessive paperwork [odds ratio (OR): 2.24, 95% confidence interval (CI): 1.32-3.80], excessive working hours (OR: 2.75, 95% CI: 1.24-6.04), low autonomy (OR: 3.92, 95% CI: 2.01-7.65), communication problems at the workplace (OR: 2.24, 95% CI: 1.05-4.76), complaints from patients (OR: 6.62, 95% CI: 1.21-36.1), peer competition (OR: 2.22, 95% CI: 1.25-3.93), and anxiety about the future (OR: 2.13, 95% CI: 1.28-3.56) - were independently associated with burnout. The burnout group had more reported patient-safety incidents that were likely to occur per year (>10) (OR: 2.65, 95% CI: 1.01-6.95) and a lack of individuals who could provide support when in trouble (OR: 1.83, 95% CI: 1.01-3.34) than the non-burnout group. Conclusion This study described the prevalence of burnout among residents who responded to our survey. We detected an association between burnout and resident-reported causes of stress, patient-safety incidents, and a lack of individuals who provide support when in trouble. Further interventional studies targeting ways to reduce these concerns are warranted.

Health care worker burnout after the first wave of the coronavirus disease 2019 (COVID-19) pandemic in Japan.

OBJECTIVES: To determine the prevalence of burnout according to job category after the first wave of COVID-19 in Japan and to explore its association with certain factors. METHODS: An online cross-sectional survey of health care workers (HCWs) from June 15 to July 6, 2020, was conducted at a tertiary hospital in Tokyo, Japan. Demographic characteristics, results of the Japanese version of the Maslach Burnout Inventory-General Survey, types of anxiety and stress, changes in life and work after the peak of the pandemic, and types of support aimed at reducing the physical or mental burden, were determined. RESULTS: Of 672 HCWs, 149 (22.6%) met the overall burnout criteria. Burnout was more prevalent in women (OR, 3.11; 95% CI, 1.45-6.67, P = .003), anxiety due to unfamiliarity with personal protective equipment (PPE) (OR, 1.98; 95% CI, 1.20-3.27, P = .007), and decreased sleep duration (OR, 1.96; 95% CI, 1.20-3.20, P = .008). Conversely, participants who felt that the delivery of COVID-19-related information (OR, .608; 95% CI, .371-.996, P = .048) and PPE education opportunities (OR, .484; 95% CI, .236-.993, P = .048) and messages of encouragement at the workplace (OR, .584; 95% CI, .352-.969; p = .037) was helpful experienced less burnout. CONCLUSIONS: There is a need to focus on the above factors to maintain the mental health of HCWs. The delivery of COVID-19-related information and educational interventions for PPE and messages of encouragement at the workplace may be needed to reduce the mental burden.

Moral distress experienced by psychiatric nurses in Japan.

This study aimed to: (1) develop and evaluate the Moral Distress Scale for Psychiatric nurses (MDS-P); (2) use the MDS-P to examine the moral distress experienced by Japanese psychiatric nurses; and (3) explore the correlation between moral distress and burnout. A questionnaire on the intensity and frequency of moral distress items (the MDS-P: 15 items grouped into three factors), a burnout scale (Maslach Burnout Inventory - General Survey) and demographic questions were administered to 391 Japanese psychiatric nurses in 2007-2008. These nurses experienced relatively low levels of moral distress despite the fact that they were commonly confronted by morally distressing situations. All the circumstances in which the participants experienced moral distress were included in the 'low staffing' factor, which reflects the characteristics of Japanese psychiatric care. The frequency score of the low staffing factor was a significant predictor of burnout.

Burnout Study of Clinical Nurses in Vietnam: Development of Job Burnout Model Based on Leiter and Maslach's Theory.

PURPOSE: This study aimed to create a Vietnamese version of both the Maslach Burnout Inventory-General Survey (MBI-GS) and Areas of Worklife Scale (AWS) to assess the burnout state of Vietnamese clinical nurses and to develop a causal model of burnout of clinical nurses. METHODS: We conducted a descriptive design using a cross-sectional survey. The questionnaire was hand divided directly by nursing departments to 500 clinical nurses in three hospitals. Vietnamese MBI-GS and AWS were then examined for reliability and validity. We used the revised exhaustion +1 burnout classification to access burnout state. We performed path analysis to develop a Vietnamese causal model based on the original model by Leiter and Maslach's theory. RESULTS: We found that both scales were reliable and valid for assessing burnout. Among nurse participants, the percentage of severe burnout was 0.7% and burnout was 15.8%, and 17.2% of nurses were exhausted. The best predictor of burnout was "on-duty work schedule" that clinical nurses have to work for 24 hours. In the causal model, we also found similarity and difference pathways in comparison with the original model. CONCLUSION: Vietnamese MBI-GS and AWS were applicable to research on occupational stress. Nearly one-fifth of Vietnamese clinical nurses were working in burnout state. The causal model suggested a range of factors resulting in burnout, and it is necessary to consider the specific solution to prevent burnout problem.

Work-family conflict as a mediator between occupational stress and psychological health among mental health nurses in Japan.

BACKGROUND: Occupational stress among mental health nurses may affect their psychological health, resulting in reduced performance. To provide high-quality, sustainable nursing care, it is necessary to identify and control the factors associated with psychological health among mental health nurses. The purpose of this study was to examine the role of work-family conflict (WFC) in the well-known relationship between occupational stress and psychological health among mental health nurses in Japan. METHODS: In this cross-sectional study, data were gathered from 180 mental health nurses who had a coresident child or were married. Data from the Work-Family Conflict Scale, the Generic Job Stress Questionnaire, the Maslach Burnout Inventory-General Survey, and the Center for Epidemiologic Studies for Depression Scale were obtained via self-report questionnaires. The effects of occupational stress and WFC on psychological health were explored by hierarchical linear regression analysis. RESULTS: The relationship between emotional exhaustion and occupational factors, including quantitative workload and the variance in workload, disappeared with the addition of WFC (each work interference with family [WIF] or family interference with work [FIW]). The relationship between emotional exhaustion and mental demands disappeared only with the addition of WIF. The relationship between depressive symptoms and variance in workload disappeared with the addition of WFC (each WIF or FIW). CONCLUSION: Our findings may encourage hospital administrators to consider the risks of medical staff WFC. Furthermore, longitudinal investigations into the factors associated with WFC are required for administrative and psychological interventions.

Cross-sectional survey of workload and burnout among Japanese physicians working in stroke care: the nationwide survey of acute stroke care capacity for proper designation of comprehensive stroke center in Japan (J-ASPECT) study.

BACKGROUND: Burnout is common among physicians and affects the quality of care. We aimed to determine the prevalence of burnout among Japanese physicians working in stroke care and evaluate personal and professional characteristics associated with burnout. METHODS AND RESULTS: A cross-sectional design was used to develop and distribute a survey to 11 211 physicians. Physician burnout was assessed using the Maslach Burnout Inventory General Survey. The predictors of burnout and the relationships among them were identified by multivariable logistic regression analysis. A total of 2724 (25.3%) physicians returned the surveys. After excluding those who were not working in stroke care or did not complete the survey appropriately, 2564 surveys were analyzed. Analysis of the participants' scores revealed that 41.1% were burned out. Multivariable analysis indicated that number of hours worked per week is positively associated with burnout. Hours slept per night, day-offs per week, years of experience, as well as income, are inversely associated with burnout. Short Form 36 mental health subscale was also inversely associated with burnout. CONCLUSIONS: The primary risk factors for burnout are heavy workload, short sleep duration, relatively little experience, and low mental quality of life. Prospective research is required to confirm these findings and develop programs for preventing burnout.

Academic report on burnout among Japanese nurses.

AIM: Japanese nurses have increasingly experienced "burnout" in the past several years. Studies on Japanese nurses are required in order to explore how to prevent nursing burnout. The objectives of this report were to: (i) introduce the concept, definition, and measurement of burnout; (ii) look at an overview of the prevalence, possible causes, and consequences of burnout among Japanese nurses; and (iii) explore how to prevent burnout among nurses. METHODS: The authors and co-researchers have been studying burnout among Japanese workers for more than 15 years. Therefore, previously performed studies were reviewed and summarized. RESULTS: In Japan, approximately 36% of human services professionals, such as nurses, were burned out compared to 18% of civil servants, and 12% of company employees. It was quite obvious that nurses are prone to burnout. The possible causes and consequences of burnout among Japanese nurses were reviewed. Excessive workloads and interpersonal conflict in the workplace were possible causes of burnout among Japanese nurses. The consequences of nurse burnout are potentially very serious, including medical accidents/errors. Issues to prevent nursing burnout were then reviewed. Enhancement of cognitive coping skills for female nurses and problem-solving skills for male nurses could contribute to prevention of burnout in nurses. CONCLUSION: The authors' previous study revealed that the new model of the organizational context of burnout developed by Leiter and Maslach could be applied to Japanese. Further examination is needed. This report supports the call to scale up burnout prevention strategy for Japanese nurses.

Effects of fatigue on immune function in nurses performing shift work.

OBJECTIVES: We investigated the effects of fatigue on NK cell function and lymphocyte subpopulations in nurses performing shift work using a longitudinal design. METHODS: Fifty-seven female nurses engaged in shift work at a hospital in Japan were selected for our study cohort. The hospital used a counterclockwise rotating three-shift system. Night shifts followed day shifts after a seven-hour interval. Immune parameters measured at the beginning of the day shift through to the end of the night shift were compared between two groups stratified by their level of fatigue. Statistical differences were evaluated after adjusting for baseline immune values and other demographic features. RESULTS: Subjective feelings of fatigue increased progressively from the beginning of day shifts to the end of night shifts. From the beginning of day shifts to the end of night shifts, NK cell activity and CD16(+)CD56(+) lymphocytes decreased, while CD3(+) and CD4(+) lymphocytes increased. The group with the greater increase in fatigue showed a larger decrease in NK cell activity and a larger increase in CD4(+)lymphocytes when compared with the group reporting less fatigue. These findings did not change after adjusting for demographic factors and sleep hours. CONCLUSION: Our data suggest that shift work has deleterious effects on NK cell function and that the effects depend on the degree of fatigue. Proper management of shift work may lessen fatigue in workers and also ameliorate many health problems experienced by shift workers.