PSYCHIATRIC NURSING

99 Azize Karahan, Chronotype and sleep quality in nurses/ dx.doi. org/10.14744/phd.2019. 90277 habits; while some individuals choose to sleep and wake up early, others prefer to sleep and wake up late. [5] Morning-type individuals sleep and wake up early, feeling energetic without intake of a stimulant such as caffeine. On the other hand, evening-type individuals sleep late at night and have difficulty in waking up in the morning; they become stimulated at the highest level in the afternoon, and therefore show better performance during the afternoon and evening hours. [7] Under normal conditions, there is a synchronization between the homeostatic process and circadian systems in the sleep− wakefulness cycle. This synchronization is necessary for restful sleep and daytime functionality; however, in many sectors, individuals may be required to work during different hours (shifts). [8] Circadian rhythm sleep−wakefulness disorders mean the changes in the circadian time-keeping system, the irregularities in the mechanism, or the disorders caused by the misalignment between the external environment and endogenous circadian rhythm. [9] Working in shifts is among the factors that cause circadian sleep-wakefulness disorders. The sleep disorders called as working in shift disorders may lead to significant mental, physical, social, occupational, educational, or other problems due to working in night shifts or various shifts that contradict with the routine sleep time. [9] In the circadian rhythm sleep−wakefulness disorders, the sleep−wakefulness rhythm may be disrupted due to an imbalance between the internal and external cycles, as well as the effects of environmental and social conditions. Continuous and repetitive interruption of the sleep−wakefulness rhythm results in functional losses by causing insomnia, excessive sleepiness, or both. [10] Sleep problems reduce the quality of life and impair individuals’ health,[2] and working in shifts has been reported to increase mortality and lead to coronary heart disease, metabolic syndrome, diabetes, impaired glucose metabolism, and accidents. [1] In addition, working in night shifts increases fatigue, which results in clear negative effects on wakefulness, attention, judgment, and mood, which may lead to accidents, malpractice, and injury. Fatigue is known to negatively affect productivity and performance by causing impaired memory, problem-solving skills, and decision-making abilities. [8] It has also been highlighted that sleep disorders negatively affect longand short-term memory, immunity (proinflammatory cytokines, IL-6 rhythmicity), hormone levels (GH, melatonin, cortisol, TSH), and metabolism (leptin, ghrelin, insulin sensitivity, glucose sensitivity). [11] Nurses are among the occupational groups who should serve for 24 hours a day and therefore work in shifts. It has been reported that nurses have more difficulty in working, reduced sleep quality, and problems such as sleep disorders, fatigue, attention deficit, and reduced productivity in problem-solving,[12–15] which may increase the possibility of errors. Sleep health is a multi-directional sleep−wakefulness pattern that supports physical and mental wellness and is adapted to the individual’s social and environmental demands. A healthy sleep is characterized by subjective satisfaction during wakefulness, appropriate timing, sufficient duration, high effciency, and continuous wakefulness. [1] Nurses should work in shifts due to the nature of their profession; however, this is known to cause an interrupted sleep pattern and certain health problems. Although studies have been conducted in recent years regarding shift work and sleep problems based on nurses’ chronotype characteristics, a limited number of studies was found in the literature. Considering the current situation, determining sleep quality, fatigue, and attention in nurses according to their shifts and chronotype characteristics may contribute to reducing problems related to productivity, employee safety, and medical errors. Materials and Method