O presente estudo trata da organização dos horários de trabalho em turnos fixos, analisando seu impacto na qualidade do sono, na utilização do tempo livre pelo trabalhador e de aspectos relacionados à sua percepção quanto à saúde. A pesquisa foi realizada com auxiliares do setor de impressão e acabamento de uma gráfica e editora localizada na cidade industrial, em Curitiba no estado do Paraná. Para avaliar a qualidade do sono, das relações sociais e da saúde, utilizou-se a versão traduzida do Standard Shiftwork Index (SSI) (JAFFE; SMOLENSKI; WUN, 1996). Para a identificação do cronotipo (vespertinidade/matutinidade) foi utilizado o questionário de Horne e Ostberg (1976). Os resultados demonstraram não haver diferenças significativas entre os três turnos quando comparados os valores médios dos escores de cada constructo, com exceção para as atividades sociais e familiares. Quando analisadas separadamente, cada questão do SSI referente ao sono, algumas tendências indicaram que quando o cronotipo é relacionado com o turno de trabalho, existem percepções diferentes quanto à qualidade do sono. Foi constatado também nos três turnos um anseio dos trabalhadores por um dia a mais de folga na semana, pois o descanso semanal não é suficiente para reparar a fadiga ocasionada pelo trabalho, principalmente para os trabalhadores do terceiro turno. / The present study analyses the organization of work shifts and their impact on sleep quality, on free time allowed by the work shift for social and family activities, and on specific health aspects perceived by the worker. The subjects of the study were workmen at a printing and publishing company in Curitiba´s Industrial District. In order to evaluate the quality of sleep, social relations, and health, the translated version of the Standard Shiftwork Index (SSI) (JAFFE; SMOLENSKI; WUN, 1996) was employed. The chronotype (evening / morning) was evaluated by use of the Horne and Ostberg (1976) questionary. Results showed no meaningful differences between the three shifts, when comparing average values of the scores for each construct, except for social and family activities. When each SSI sleep related question was analysed separately, there were trends which indicated that when the chronotype is related to work shift, there are different perceptions of sleep quality. A common wish of the workpeople in all three shifts is one extra day off during the week, since it is felt that the weekly rest is not enough to repair work related fatigue, especially for those in the third shift.

O presente estudo trata da organização dos horários de trabalho em turnos fixos, analisando seu impacto na qualidade do sono, na utilização do tempo livre pelo trabalhador e de aspectos relacionados à sua percepção quanto à saúde. A pesquisa foi realizada com auxiliares do setor de impressão e acabamento de uma gráfica e editora localizada na cidade industrial, em Curitiba no estado do Paraná. Para avaliar a qualidade do sono, das relações sociais e da saúde, utilizou-se a versão traduzida do Standard Shiftwork Index (SSI) (JAFFE; SMOLENSKI; WUN, 1996). Para a identificação do cronotipo (vespertinidade/matutinidade) foi utilizado o questionário de Horne e Ostberg (1976). Os resultados demonstraram não haver diferenças significativas entre os três turnos quando comparados os valores médios dos escores de cada constructo, com exceção para as atividades sociais e familiares. Quando analisadas separadamente, cada questão do SSI referente ao sono, algumas tendências indicaram que quando o cronotipo é relacionado com o turno de trabalho, existem percepções diferentes quanto à qualidade do sono. Foi constatado também nos três turnos um anseio dos trabalhadores por um dia a mais de folga na semana, pois o descanso semanal não é suficiente para reparar a fadiga ocasionada pelo trabalho, principalmente para os trabalhadores do terceiro turno. / The present study analyses the organization of work shifts and their impact on sleep quality, on free time allowed by the work shift for social and family activities, and on specific health aspects perceived by the worker. The subjects of the study were workmen at a printing and publishing company in Curitiba´s Industrial District. In order to evaluate the quality of sleep, social relations, and health, the translated version of the Standard Shiftwork Index (SSI) (JAFFE; SMOLENSKI; WUN, 1996) was employed. The chronotype (evening / morning) was evaluated by use of the Horne and Ostberg (1976) questionary. Results showed no meaningful differences between the three shifts, when comparing average values of the scores for each construct, except for social and family activities. When each SSI sleep related question was analysed separately, there were trends which indicated that when the chronotype is related to work shift, there are different perceptions of sleep quality. A common wish of the workpeople in all three shifts is one extra day off during the week, since it is felt that the weekly rest is not enough to repair work related fatigue, especially for those in the third shift.

O presente estudo trata da organização dos horários de trabalho em turnos fixos, analisando seu impacto na qualidade do sono, na utilização do tempo livre pelo trabalhador e de aspectos relacionados à sua percepção quanto à saúde. A pesquisa foi realizada com auxiliares do setor de impressão e acabamento de uma gráfica e editora localizada na cidade industrial, em Curitiba no estado do Paraná. Para avaliar a qualidade do sono, das relações sociais e da saúde, utilizou-se a versão traduzida do Standard Shiftwork Index (SSI) (JAFFE; SMOLENSKI; WUN, 1996). Para a identificação do cronotipo (vespertinidade/matutinidade) foi utilizado o questionário de Horne e Ostberg (1976). Os resultados demonstraram não haver diferenças significativas entre os três turnos quando comparados os valores médios dos escores de cada constructo, com exceção para as atividades sociais e familiares. Quando analisadas separadamente, cada questão do SSI referente ao sono, algumas tendências indicaram que quando o cronotipo é relacionado com o turno de trabalho, existem percepções diferentes quanto à qualidade do sono. Foi constatado também nos três turnos um anseio dos trabalhadores por um dia a mais de folga na semana, pois o descanso semanal não é suficiente para reparar a fadiga ocasionada pelo trabalho, principalmente para os trabalhadores do terceiro turno. / The present study analyses the organization of work shifts and their impact on sleep quality, on free time allowed by the work shift for social and family activities, and on specific health aspects perceived by the worker. The subjects of the study were workmen at a printing and publishing company in Curitiba´s Industrial District. In order to evaluate the quality of sleep, social relations, and health, the translated version of the Standard Shiftwork Index (SSI) (JAFFE; SMOLENSKI; WUN, 1996) was employed. The chronotype (evening / morning) was evaluated by use of the Horne and Ostberg (1976) questionary. Results showed no meaningful differences between the three shifts, when comparing average values of the scores for each construct, except for social and family activities. When each SSI sleep related question was analysed separately, there were trends which indicated that when the chronotype is related to work shift, there are different perceptions of sleep quality. A common wish of the workpeople in all three shifts is one extra day off during the week, since it is felt that the weekly rest is not enough to repair work related fatigue, especially for those in the third shift.

O trabalho noturno e a alternância de turnos são identificados como fatores de maximização de efeitos negativos na saúde do trabalhador, como o estresse e a fadiga, por dificultarem a adaptação do ritmo circadiano do cortisol ao de trabalho. Objetivo: investigar o efeito do esquema de trabalho em turnos fixo e alternante e noturno de enfermeiros nos índices de estresse ocupacional e fadiga e na expressão circadiana do cortisol salivar. Método: estudo observacional de corte transversal e abordagem quantitativa dos dados estruturado com base no referencial teórico de Cooper. Realizado com 104 enfermeiros das Unidades de Emergência e Bloco Cirúrgico de hospital de ensino público do Estado de São Paulo e outro de Minas Gerais, no período de janeiro a março de 2017. Índices de estresse e fadiga foram mensurados por meio da aplicação de dois instrumentos: o Inventário de Estresse em Enfermeiros e a Escala de Avaliação de Fadiga, ambos validados para utilização no Brasil. A quantificação do cortisol salivar foi realizada por meio da técnica de ELISA. O projeto foi aprovado pelo Comitê de Ética em pesquisa sob protocolo. 55695416.7.0000.5393. Resultados: 66,67% dos enfermeiros trabalhavam em esquema de turnos alternantes e 39,39% eram fixos no turno matutino. Constatou-se 50,8% apresentaram alto índice de estresse e 46,03% fadiga. Não foram observadas associações estatisticamente significativas entre índices de cortisol salivar, turno de trabalho, esquema de turno fixo ou alternante, estresse e fadiga. Entretanto, profissionais de enfermagem de unidades críticas que trabalhavam em esquema de turnos alternante e matutino apresentaram tendência a mais altos índices de estresse e fadiga e menor secreção de cortisol ao longo do dia de trabalho do que aqueles dos turnos fixo e noturno. A fadiga mostrou-se significativa e positivamente correlacionada com a secreção total de cortisol no período da manhã. Conclusão: Os achados do presente estudo fornecem evidências de uma dessincronização do eixo HipotálamoHipófise-Adrenal em enfermeiros dos turnos alternante e matutino e, consequentemente, maior susceptibilidade destes ao desenvolvimento de doenças cardíacas, metabólicas e imunológicas / Night-work and shiftwork are identified as maximizing negative effects on worker health, such as stress and fatigue, by making it difficult to adapt the circadian rhythm of cortisol to work. Objective: to investigate the effect of the fixed and alternating and nocturnal shifts of nurses on the occupational stress index, fatigue and circadian expression of salivary cortisol. Method: observational, cross-sectional and quantitative study based on Cooper\'s theoretical framework. Performed with 104 nurses from the emergency units and surgical center of a public teaching hospital in the State of São Paulo and another from Minas Gerais, from January to March, 2017. Stress and fatigue indexes were measured using two instruments, the Nurses\' Stress Inventory and the Fatigue Assessment Scale, both of which were validated and salivary cortisol quantification was performed by ELISA assay. The project was approved by the Research Ethics Committee under protocol. 55695416.7.0000.5393. Results: 66.67% of the nurses worked on alternating shifts and 39.39% were fixed on the morning shift. It was found that 50.8% of the nurses had a high stress index and 46.03% presented fatigue. There were no statistically significant associations between salivary cortisol index, shiftwork, fixed or alternating shift scheme, stress and fatigue. However, nursing professionals from critical units who worked in an alternating and morning shift schedule showed a trend towards higher levels of stress and fatigue and lower cortisol secretion throughout the workday than fixed and night shift workers. Fatigue was significantly and positively correlated to overall morning cortisol. Conclusions: The findings of the present study provide evidence of a hypothalamic-pituitary-adrenal axis desynchronization in nurses of the alternating and morning shift and, consequently, a greater susceptibility of these to the development of cardiac, metabolic and immunological diseases

Background: Most likely given the increase in sick leave absence with mental health issues as the dominant cause, the Swedish Work Environment Agency has released a new regulation regarding the organisational and psychosocial work environment. Shiftwork has been given special attention. Nurses often perform shiftwork and are one of the professions most vulnerable to work stress, ill health and burnout syndrome. Swedish municipalities has therefore initiated an organisational change to implement a schedule model that considers research on work health, but also to solve staffing issues and keep the budget in balance. Assistant nurses have taken to social and traditional media to raise objections to these new schedules.  Objectives: The aim is to examine how discursive practices are used in opinion texts to argue against the organisational change within Swedish municipalities through looking at the narrative structure of the texts and how the nurses’ identities are made relevant in the text.  Methods: A discursive psychological analysis that examines the way language is used to establish the definition of the situation and gain control over the narrative. Data sources included 27 opinion texts from Swedish media newspapers that were publicly available. Results: Three themes were identified: the structure of the narrative, the issue of money and the construction of the nurses. The structure of narrative drew on two linguistic trends: pseudo-academic language and emotive language to describe the situation at hand. In the issue of money they attributed saving money and greed as behind the implementation of the new schedule model, rather than concern over the staff’s welfare. In contrast they constructed themselves as being humble, reasonable and caring about the care receivers. Conclusions: The assistant nurses used language in the opinion texts to take control over the narrative by drawing on aspects relating to health, attributions of motive for the implementation of this organisational change and constructing themselves as being reasonable, humble and caring for the care receivers in contrast to a calculating, greedy employer who cares only about money. The nurses’ working environment is constructed as impacting on the well-being of care-receivers. The nurses position themselves against discourses relating to cost efficiency, rationalisation, and emphasis on administration.

The operational work of air traffic controllers (ATCOs) is characterized by continuous and demanding cognitive tasks. Duties include ensuring a safe and efficient movement of aircraft, often operating in a 24/7 system necessitating shift-based work schedules. However, the nature of shift work introduces significant challenges related to fatigue and its potential impact on performance and safety. Fatigue is a complex physiological and psychological phenomenon originating from multiple factors such as prolonged wakefulness, inadequate sleep, and disruption to circadian rhythms. Those aspects are mainly influenced by working times, shift work, and the shift system itself. Fatigue can impair cognitive functions, including attention, reaction time, decision-making, and memory recall – critical abilities for ATCOs. Organizations and regulators are mandated to develop approaches aimed at reducing fatigue and the associated risks. Currently, fatigue is often managed through a compliance-based approach, which prescribes strict duty time limitations. However, this method oversimplifies fatigue as a non-issue in the workplace, merely because these limitations are adhered to. Recognizing the inaccuracy of this approach, a risk-based approach has been introduced. The approach acknowledges that varying degrees of fatigue risks may be present throughout a shift. This psychologically more accurate perspective has driven a change towards the fatigue risk management system (FRMS). A given shift system has a major influence on fatigue and is critical for any FRMS introduction. The actual shift design and scheduled roster can vary between industries and among air traffic control (ATC) organizations. Heterogenous shift systems differ in terms of fixed or irregular rotation, rotation direction, shift length, recovery times, minimum time between consecutive shifts, and maximum of worked hours per week or month. The impact of these factors on fatigue is, however, underexplored in ATC. A critical consideration of the shift system is indicated. For this dissertation, an irregular and preference-based shift system was investigated. Irregular shift systems, as opposed to fixed shift schedules, offer more variability in the distribution of work shifts over a roster period. The shift combinations do not follow a fixed order. Preference-based shift systems allow workers to request individualized rosters, encompassing their preferred shift types and duty days for the roster period. Particularly with regard to an irregular and preference-based shift system in ATC, there is a lack of systematically obtained fatigue data. The aim of this dissertation is to enhance the understanding of fatigue in an irregular and preference-based shift system in ATC. The shift system was investigated with a focus on fatigue dynamics and their relation to shift types, rostering factors, and night shift design as well as the consistency of subjective and objective fatigue data. In order to understand fatigue in the given irregular shift system, two field studies were conducted at different points in time, using a widely identical methodological approach. Both studies were conducted at an area control center. Fatigue was measured with a subjective and an objective method over a three-week period in all operational shifts at three key timepoints: beginning, middle, and end of the shift. Study 1 covered all four shift types (including morning, evening, and two night shifts) and investigated the differences within and between shift types. Moreover, the influence of the rotation direction and time between shifts was investigated. The results revealed a positive association between time on shift and objective fatigue. Objective fatigue increased significantly in the first half of all shifts, but then maintained at a certain level. However, this effect was moderated by the time of day, with night shifts resulting in overall increased objective fatigue in the middle and end of shifts compared to day shifts. Subjective fatigue increased over time only for the evening and one night shift type. Comparisons between shift types mostly showed higher subjective fatigue during night shifts compared to day shifts. Time on shift appeared to be the most relevant fatigue factor for day shifts, while the time of day was more relevant for night shifts. Individuals working the night shift had a longer continuous duty time, which likely explains the association with fatigue, even though task demands tend to be lower at night. Considering the rostering factors, shift combinations that had less than 11 hours between shifts (quick returns) and a counterclockwise rotation direction were associated with increased fatigue at the beginning of the subsequent duty. Interestingly, this effect diminished as the shifts proceeded. Analyses of the sleep quantity prior the shifts showed differences between all shift types, with the shortest sleep duration before morning shifts and longest prior to evening shifts. Discrepancies between subjective and objective fatigue were found. Study 2 focused on night shifts. A single split night shift arrangement was given. The arrangement included two mirrored night shift types (NA and NB), with sleep and operational phases alternating mid-shift. Both shifts commenced at 10 p.m., with NA starting operational work while NB begun with a sleep phase and being on-call. Around 3 a.m., NB took over from NA and continued operational work until the end of the shift at 7 a.m., while NA had the opportunity to sleep from 3 a.m. onwards and remaining on-call. In addition to the measurements at the key timepoints, subjective fatigue data was collected at four times during the operational work phase. The investigation of the split night shift arrangement showed that, regardless of the night shift type (NA or NB), there was a main effect of time on shift for both subjective and objective fatigue. Comparisons between both night shift types revealed minimal differences. Subjective higher fatigue was observed at the beginning of the shift for NB, although this effect was not observed for objective fatigue. Analysis of sleep duration prior to operational work revealed different preparation mechanisms among participants depending on the type of night shift worked. Specifically, the analysis showed that the average sleep duration prior to the shift was more than one hour shorter for NB compared to NA. However, the cumulative sleep duration prior to the operational work phase was longer for NB, as they achieved an average of three hours and 46 minutes of on-shift sleep. Again, discrepancies between subjective and objective fatigue were found. The objective of enhancing the understanding of fatigue in an irregular and preference-based shift system in ATC has been achieved. A positive association between time on shift and fatigue was found across both studies, predominantly in the first shift half. The results emphasize the crucial role of rostering in subjective and objective fatigue. The revealed discrepancies between self-evaluated (subjective) and performance-based (objective) fatigue might lead to safety risks, as individuals are not aware of reduced performance capabilities due to fatigue and they may request inadequate shift combinations. The interaction of fatigue with secondary factors is discussed, highlighting considerations when implementing an FRMS.

Objetivos. Este estudo teve como objetivos avaliar a capacidade para o trabalho, a estrutura temporal do sono, da 6-sulfatoximelatonina e do cortisol em trabalhadores em turnos da área de enfermagem. Métodos. Foram realizados dois estudos. Um estudo transversal para analisar a capacidade para o trabalho e o envelhecimento funcional precoce, através de questionários de condições de vida e trabalho e sintomas de saúde, da qual participaram 696 profissionais da área de enfermagem. E um cronobiológico com 19 trabalhadores do sexo feminino. Neste foram avaliados: o ciclo vigília-sono, através de actígrafos e protocolos diários de atividades; as concentrações da 6-sulfatoximelatonina e do cortisol; e a ritmicidade circadiana (avaliada utilizando a metodologia do ajuste dos parâmetros ritmométricos pela curva cosseno, método cosinor). Foi realizada coleta de urina em dois períodos de 4 dias consecutivos (com dias de trabalho e de folga,) para os trabalhadores noturnos, submetidos a turnos de 12 horas seguidas de 36 horas de descanso; e em um período de 8 dias consecutivos para os trabalhadores diurnos (6 dias de trabalho e 2 de folga). O grupo de 19 pessoas também foi analisado segundo a maior e menor tolerância ao trabalho em turnos. A tolerância ao trabalho em turnos foi avaliada utilizando 9 indicadores de saúde (escore de sonolência e fadiga, escore de concentração e atenção, escore da fadiga projetada sobre o corpo, escore geral da fadiga, SRQ20, escore de insônia, sonolência no trabalho, escore de problemas de sono) e disponibilidade do tempo livre. Resultados. A idade média da população era de 34,9 anos (dp + 9,5 anos), e esta era predominantemente feminina (87,8%), sendo que 40,6% começou a trabalhar antes dos 18 anos. As variáveis ligadas à capacidade para o trabalho inadequada foram: 1) sócio-demográficas: ter a responsabilidade pela renda familiar sozinho (OR=1,922), ter filhos ou menores sob a guarda (OR=1,558) e ter menos de 40 anos (OR=1,400). 2) ligadas ao trabalho: referir desconforto térmico (OR=1,548), referir ter sofrido abuso verbal pelo menos duas vezes no último ano (OR=1,670). 3) variáveis ligadas à saúde foram referir obesidade (OR=2,714), doenças de sono (OR=1,681), e fadiga (OR>3,771). No segundo estudo, as trabalhadoras noturnas apresentaram maior duração, e também melhor qualidade de sono noturno. Estas também referiram níveis de alerta significantemente mais elevados quando puderam cochilar durante o turno de trabalho. Foi encontrada uma grande variabilidade nos parâmetros rítmicos ao longo dos dias de trabalho e de folga. As concentrações médias de 6-sulfatoximelatonina e cortisol das trabalhadoras noturnas foram estatisticamente menores do que as encontradas em trabalhadores diurnos (p<0,001). Quando as trabalhadoras foram classificadas como mais e menos tolerantes ao trabalho em turnos, as trabalhadoras noturnas menos tolerantes referiram menor qualidade de sono e menores níveis de alerta. As concentrações médias de 6-sulfatoximelatonina e cortisol ao longo dos dias de trabalho e de folga variaram de modo distinto nos grupos de trabalhadoras mais e menos tolerantes ao trabalho em turnos. Conclusões. A capacidade de trabalho inadequada é resultado da associação de variáveis de múltiplas naturezas, tais como condições de vida e trabalho, hábitos e estilos de vida e à organização do trabalho. O cochilo durante o turno noturno de trabalho mostrou ser efetivo na manutenção dos níveis de alerta durante o trabalho noturno. As trabalhadoras noturnas apresentaram menores concentrações médias de 6-sulfatoximelatonina quando comparadas as trabalhadoras diurnas, o que pode estar relacionado à exposição à luz durante o turno noturno de trabalho. As trabalhadoras noturnas apresentaram menores concentrações de cortisol quando comparadas as trabalhadoras diurnas, o que pode estar relacionado à maior fadiga referida por estas trabalhadoras. Os ritmos de 6-sulfatoximelatonina e cortisol têm comportamentos diferentes nos grupos de trabalhadoras mais e menos tolerantes ao trabalho em turnos, mas nenhum padrão pode ser definido, uma vez que existe uma grande variabilidade individual. / Objectives. The aim of this study was to evaluate work ability and biological rhythms of health care shiftworkers. Methods. To evaluate the work ability it was designed an epidemiological approach using a comprehensive questionnaire which included working and living conditions and health symptoms. 696 health care shiftworkers participated in this study. A sub sample of 19 female registered nurses and nurse aides/technicians were invited and agreed to participate in the chronobiological evaluation. Workers answered daily logs and wore actigraphs (Ambulatory Monitoring) to monitor activity and evaluate rest and waking periods along data collection. Urine samples were collected and voided volumes were measured during two periods of four consecutive days (working days and days off) of night workers, submitted to 12 hour night shifts followed by 36 hour off, and during one period of 8 consecutive days (six working days and two days off). It was also evaluated the 6-sulphatoxymelatonin and cortisol concentration, and their circadian rhythmicity using the Cosinor method. These 19 nurses were evaluated as more or less tolerant to shiftwork. The tolerance to shiftwork was evaluated by 9 health scores(dull and sleepy score, decline of working motivation, projection of fatigue to some parts of the body, general fatigue score, Self-Report Questionnaire (SRQ-20 score), insomnia score, sleepiness score, sleep disturbances score) and availability of free time. Results. Mean age of the respondents was 34.9 years, most of them female (87.8%) and 40.6% entered labor force before 18 years old. The socio-demographic factors associated to inadequate work ability were: income responsibility - sole breadwinner (OR=1.922), raising kids (OR=1.558), age group (under 40 years old) (OR=1,400). Factors associated with working conditions were: thermal discomfort (OR=1.548), and verbal abuse (OR=1.670). Obesity (OR=2.14), sleep problems (OR=1.681) and fatigue (OR>3.771) were health outcomes associated to inadequate work ability. Night workers showed longer mean sleep duration and referred better sleep quality to nocturnal sleep. These workers also reported higher alertness level when they nap during the night shift. Mean concentration of 6-sulphatoxymelatonin and cortisol among night workers were significantly lower than the day workers concentrations (p<0,001). When workers were classified into more and less tolerant to shiftwork, the less tolerant night workers referred worst sleep quality and lower alertness levels. The mean concentration of 6-sulphatoxymelatonin and cortisol, during working days and days off, showed distinct behavior in the two groups. It was found a great variability of the rhythmic parameters during working days and days off. Conclusions. Inadequate work ability was associated with a number of variables present at work and living conditions. Strategy of taking naps during night work was effective to maintain the alertness levels during work. Night workers 6-sulphatoxymelatonin mean concentrations were lower than day workers concentration. This might be related to light exposure during the night shift. The higher reported fatigue by these workers might explain the lower cortisol mean concentration presented by night workers when compared to day workers. The rhythms of 6-sulphatoxymelatonin and cortisol showed different behaviors when compared more and less tolerant workers, but any standard behavior could be observed since there is a great individual variability.

Objetivos. Este estudo teve como objetivos avaliar a capacidade para o trabalho, a estrutura temporal do sono, da 6-sulfatoximelatonina e do cortisol em trabalhadores em turnos da área de enfermagem. Métodos. Foram realizados dois estudos. Um estudo transversal para analisar a capacidade para o trabalho e o envelhecimento funcional precoce, através de questionários de condições de vida e trabalho e sintomas de saúde, da qual participaram 696 profissionais da área de enfermagem. E um cronobiológico com 19 trabalhadores do sexo feminino. Neste foram avaliados: o ciclo vigília-sono, através de actígrafos e protocolos diários de atividades; as concentrações da 6-sulfatoximelatonina e do cortisol; e a ritmicidade circadiana (avaliada utilizando a metodologia do ajuste dos parâmetros ritmométricos pela curva cosseno, método cosinor). Foi realizada coleta de urina em dois períodos de 4 dias consecutivos (com dias de trabalho e de folga,) para os trabalhadores noturnos, submetidos a turnos de 12 horas seguidas de 36 horas de descanso; e em um período de 8 dias consecutivos para os trabalhadores diurnos (6 dias de trabalho e 2 de folga). O grupo de 19 pessoas também foi analisado segundo a maior e menor tolerância ao trabalho em turnos. A tolerância ao trabalho em turnos foi avaliada utilizando 9 indicadores de saúde (escore de sonolência e fadiga, escore de concentração e atenção, escore da fadiga projetada sobre o corpo, escore geral da fadiga, SRQ20, escore de insônia, sonolência no trabalho, escore de problemas de sono) e disponibilidade do tempo livre. Resultados. A idade média da população era de 34,9 anos (dp + 9,5 anos), e esta era predominantemente feminina (87,8%), sendo que 40,6% começou a trabalhar antes dos 18 anos. As variáveis ligadas à capacidade para o trabalho inadequada foram: 1) sócio-demográficas: ter a responsabilidade pela renda familiar sozinho (OR=1,922), ter filhos ou menores sob a guarda (OR=1,558) e ter menos de 40 anos (OR=1,400). 2) ligadas ao trabalho: referir desconforto térmico (OR=1,548), referir ter sofrido abuso verbal pelo menos duas vezes no último ano (OR=1,670). 3) variáveis ligadas à saúde foram referir obesidade (OR=2,714), doenças de sono (OR=1,681), e fadiga (OR>3,771). No segundo estudo, as trabalhadoras noturnas apresentaram maior duração, e também melhor qualidade de sono noturno. Estas também referiram níveis de alerta significantemente mais elevados quando puderam cochilar durante o turno de trabalho. Foi encontrada uma grande variabilidade nos parâmetros rítmicos ao longo dos dias de trabalho e de folga. As concentrações médias de 6-sulfatoximelatonina e cortisol das trabalhadoras noturnas foram estatisticamente menores do que as encontradas em trabalhadores diurnos (p<0,001). Quando as trabalhadoras foram classificadas como mais e menos tolerantes ao trabalho em turnos, as trabalhadoras noturnas menos tolerantes referiram menor qualidade de sono e menores níveis de alerta. As concentrações médias de 6-sulfatoximelatonina e cortisol ao longo dos dias de trabalho e de folga variaram de modo distinto nos grupos de trabalhadoras mais e menos tolerantes ao trabalho em turnos. Conclusões. A capacidade de trabalho inadequada é resultado da associação de variáveis de múltiplas naturezas, tais como condições de vida e trabalho, hábitos e estilos de vida e à organização do trabalho. O cochilo durante o turno noturno de trabalho mostrou ser efetivo na manutenção dos níveis de alerta durante o trabalho noturno. As trabalhadoras noturnas apresentaram menores concentrações médias de 6-sulfatoximelatonina quando comparadas as trabalhadoras diurnas, o que pode estar relacionado à exposição à luz durante o turno noturno de trabalho. As trabalhadoras noturnas apresentaram menores concentrações de cortisol quando comparadas as trabalhadoras diurnas, o que pode estar relacionado à maior fadiga referida por estas trabalhadoras. Os ritmos de 6-sulfatoximelatonina e cortisol têm comportamentos diferentes nos grupos de trabalhadoras mais e menos tolerantes ao trabalho em turnos, mas nenhum padrão pode ser definido, uma vez que existe uma grande variabilidade individual. / Objectives. The aim of this study was to evaluate work ability and biological rhythms of health care shiftworkers. Methods. To evaluate the work ability it was designed an epidemiological approach using a comprehensive questionnaire which included working and living conditions and health symptoms. 696 health care shiftworkers participated in this study. A sub sample of 19 female registered nurses and nurse aides/technicians were invited and agreed to participate in the chronobiological evaluation. Workers answered daily logs and wore actigraphs (Ambulatory Monitoring) to monitor activity and evaluate rest and waking periods along data collection. Urine samples were collected and voided volumes were measured during two periods of four consecutive days (working days and days off) of night workers, submitted to 12 hour night shifts followed by 36 hour off, and during one period of 8 consecutive days (six working days and two days off). It was also evaluated the 6-sulphatoxymelatonin and cortisol concentration, and their circadian rhythmicity using the Cosinor method. These 19 nurses were evaluated as more or less tolerant to shiftwork. The tolerance to shiftwork was evaluated by 9 health scores(dull and sleepy score, decline of working motivation, projection of fatigue to some parts of the body, general fatigue score, Self-Report Questionnaire (SRQ-20 score), insomnia score, sleepiness score, sleep disturbances score) and availability of free time. Results. Mean age of the respondents was 34.9 years, most of them female (87.8%) and 40.6% entered labor force before 18 years old. The socio-demographic factors associated to inadequate work ability were: income responsibility - sole breadwinner (OR=1.922), raising kids (OR=1.558), age group (under 40 years old) (OR=1,400). Factors associated with working conditions were: thermal discomfort (OR=1.548), and verbal abuse (OR=1.670). Obesity (OR=2.14), sleep problems (OR=1.681) and fatigue (OR>3.771) were health outcomes associated to inadequate work ability. Night workers showed longer mean sleep duration and referred better sleep quality to nocturnal sleep. These workers also reported higher alertness level when they nap during the night shift. Mean concentration of 6-sulphatoxymelatonin and cortisol among night workers were significantly lower than the day workers concentrations (p<0,001). When workers were classified into more and less tolerant to shiftwork, the less tolerant night workers referred worst sleep quality and lower alertness levels. The mean concentration of 6-sulphatoxymelatonin and cortisol, during working days and days off, showed distinct behavior in the two groups. It was found a great variability of the rhythmic parameters during working days and days off. Conclusions. Inadequate work ability was associated with a number of variables present at work and living conditions. Strategy of taking naps during night work was effective to maintain the alertness levels during work. Night workers 6-sulphatoxymelatonin mean concentrations were lower than day workers concentration. This might be related to light exposure during the night shift. The higher reported fatigue by these workers might explain the lower cortisol mean concentration presented by night workers when compared to day workers. The rhythms of 6-sulphatoxymelatonin and cortisol showed different behaviors when compared more and less tolerant workers, but any standard behavior could be observed since there is a great individual variability.

Personer som utför skiftarbete ingår i en riskgrupp för hälsorelaterade påfrestningar som resultat av en svårighet att utveckla personliga rutiner för kost, vila och friskvård. Nautiker som arbetar på fartyg där tvåvaktssystem om sex timmar tillämpas ingår således i denna riskgrupp där arbetet i regel förläggs koncentrerat över en längre tidsperiod. I denna studie presenteras en undersökning om hur personer med erfarenhet av tvåvaktssystem upplever förutsättningarna för att skapa sunda rutiner för vila, kost och friskvård. Resultatet är en berättelse om upplevda förutsättningar och i det har följande två intressanta slutsatser framkommit: Respondenterna upplever att frivaktens teoretiska tidsrymd för återhämtning inte överensstämmer med verkligheten varpå sömn och kost prioriteras medan behovet av friskvård blir lidande. Personliga rutiner är avgörande men förutsättningarna för att skapa sunda rutiner för vila, kost och friskvård står i direkt relation till möjligheten att få sin frivakt ostörd från beordrade driftrelaterade arbetsmoment. / Persons that perform shift work are part of a risk group for health related stress as result of difficulties with developing personal routines for eating, sleeping and physical wellness. Sailors that work in ships where a two watch system with 6 hour watches is applied are therefore included in this risk group where work is generally concentrated over an extended period of time. This study presents an investigation on how people with experience in the two watch system with six hour watches, experience the conditions for creating healthy routines for sleep, diet and physical wellness. The result is a story about the perceived opportunities in which the following two interesting conclusions emerged: respondents feel that the off duty period's theoretical timeframe for regeneration doesn't correspond to reality in which the time does not suffice. Hence, sleep and nutrition is prioritized while the need for physical wellness suffers. Personal routines are essential, but prerequisites for developing healthy routines for sleep, diet and wellness are directly related to the possibility of having the off duty period undisturbed from ordered operational tasks.

Approved for public release, distribution is unlimited / This study investigates the effects of reversing sleep-wake cycles on mood, sleep, and fatigue of the crewmembers and Air Wing 9 of the USS JOHN C. STENNIS (CVN-74). It also reviews the research conducted in sleep deprivation, circadian rhythms, shiftwork, fatigue, and mood. The effects of reversing sleep-wake cycle on mood of the crewmembers were analyzed by assessing a repeated administration of the Profile of Mood States (POMS). Mood states were monitored at three time points associated with the current work schedule (night shift vs. day shift) of the crewmembers. The results showed that younger participants were angrier than older participants on night shiftwork. The results also indicated that there was a significant interaction between repeated measures of mood states and gender. In addition, female participants reported significantly higher mood scale scores than the male participants, and topside participants were getting significantly less sleep than belowdecks participants. Given these findings, this area of research warrants further exploration. There is a significant need to educate military personnel of the effects of sleep deprivation and shiftwork on their job performance and individual health and safety. / Ensign, United States Navy