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Year : 2018  |  Volume : 11  |  Issue : 1  |  Page : 13-18
Prevalence and effects of sleep disorders among shift-working nurse

1 Department of Occupational Health, Larestan School of Medical Sciences, Larestan, Iran
2 Department of Public Health, Ewaz School of Health, Larestan School of Medical Sciences, Larestan, Iran
3 Department of Public Health, School of Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4 Department of Nursing, School of Nursing, Larestan School of Medical Sciences, Larestan, Iran
5 Department of Health Education and Promotion, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

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Date of Web Publication10-Dec-2019


Introduction: Sleep is one of the basic and physiologic needs of humans which has impressive effects on the physical and mental health of human. According to the need for the permanent presence of nurses in the hospitals, they often suffer from shift-working effects such as sleep disorders. Considering the high sensitivity of nursing jobs, the aims of this study was to evaluate the prevalence and consequence of sleep disorders in shift-working nurses. Materials and Methods: This cross-sectional study is conducted on all of the nurses employing in hospitals of Larestan City in South of Iran at 2017. After screening based on inclusion criteria, 100 nurses were selected. To evaluate of prevalence and consequence of sleep disorders in nurses, the Pittsburgh sleep quality index, Epworth sleep quality index, and insomnia severity index were used. Data were analyzed using SPSS Version 16. Results: The results showed the mean score of sleep quality index was 6.52 ± 4.23, and according to this index, 56% of studied nurses are in hazard situation. In all of the nurses, sings of insomnia during routine works was observed, so that 78.5% were sleepy, 16.5% were very sleepy, and 5% were severe sleepy. With increasing the rate of night shift-working per week, the severity of insomnia in nurses was increased too (R 2 = 0.78). Sleep disorders in surgical section nurses were higher than nurses in other section of the hospitals (P < 0.05). Conclusions: A high percentage of nurses employed in different section of hospitals have poor sleep quality and increase the rate of night shift working per week plays a major role in decreasing their sleep quality. Regarding the adverse effects due to poor sleep quality on health status and quality of job performance of nurses, it is necessary adjust the shift works of nurses to improve the sleep quality of nurses night shift-working employed in different section of hospitals.

Keywords: Nurses, shift work, sleep disorders, sleep hygiene

How to cite this article:
Bazrafshan MR, Moravveji F, Soleymaninejad N, Zare F, Rahimpoor R, Zolghadr R. Prevalence and effects of sleep disorders among shift-working nurse. Ann Trop Med Public Health 2018;11:13-8

How to cite this URL:
Bazrafshan MR, Moravveji F, Soleymaninejad N, Zare F, Rahimpoor R, Zolghadr R. Prevalence and effects of sleep disorders among shift-working nurse. Ann Trop Med Public Health [serial online] 2018 [cited 2020 Jun 4];11:13-8. Available from:

   Introduction Top

Sleep is one of the important elements in night-time cycles, which is associated with the reconstruction of physical and emotional powers. About a third of human life is devoted to sleep, and more than 30% of the world suffers from sleep disorders that can be caused by mental-psychological diseases, physical disease, second job, night working, and so on.[1],[2] Sleep quality is important from two perspectives: the first is being common the complaint about the lack of high-quality sleep among the general people, such as frequent waking up of sleep and lack of having deep sleep, and the second is the weakness of sleep quality of people such as shortness of sleep time duration.[3],[4]

One of the most important areas for sustainable health development in human societies is the health and care sector, that nurses are considered the largest professional group in this therapeutic system, so that nurses form usually 40% of hospital employees and 55% of the total employees costs is allocated to them.[5],[6],[7] In the health and care sector, the proportion of people who work at night is more than those people working in other public service providing areas, so that 36.9% of the hospital employees had been night working and they are often nurses.[8]

Shift work disorder is defined as a sleep disorder characterized by insomnia or insomnia in the daily schedule of a person.[9] Working in night shift had been unlike human nature and will cause to make disorder in night-time rhythm (biological clock or circadian rhythm) and other adverse health effects, such as cardiovascular disorders, digestive disorders, reproductive system disorders, decreasing efficacy, and increasing rate of occurrence the incident in the employees.[10],[11] The nature of the nursing job and their occupational stress, along with the harmful physical factors, cause sleep disorder and cause sleepiness in the day.[12],[13]

Lack of sleep and inadequate sleep quality as one of the effects caused by shift working can lead to depression, lack of concentration, decreasing immune system function, hypertensive, cardiovascular risks, and reducing of activity and talent level of people.[11],[14] Several studies have shown that mortality rate in people with a sleep time less than 3.5 h and more than 8.5 h is higher than those people with a sleep hour of 7 h a day. Furthermore, having a history of insomnia is considered one of the most important variables of occurrence depression, so that people not having a history of depression but with suffered from to sleep disorder have a risk of suffered from to major depression in the future, roughly double of others. Therefore, nurses deprived of public health and well- being will not be able to perform and provide physical and psychological support to their caregiver patients in competency way, which this matter will increase the risk of mistakes and occurrence of occupational accidents, which ultimately its outcome will affected not only on nurses but also on patient and the general public.[8],[15],[16],[17]

Finally, disorder in the quality of sleep will disrupt the quality of nursing services, which in addition to delaying the patient's health improvement process and benefiting from proper and timely care providing, will also cause reduce productivity and quality of performance of the nurses, so nurses must have a sleep quality and consequently the good quality of life to provide proper and correct services.[18],[19]

In a study by Flo et al. that conducted on shift working disorders in nurses in 2012, it was found that sleepiness disorders, insomnia, and shift-working symptoms increase followed by increasing regular nocturnal work in nurses.[9]

A study that was conducted by Eldevik et al. in 2013 with the aim to investigate the adverse effects of night working on nurses, it was founded that the incidence rate of insomnia, too much sleepiness, excessive fatigue, and disorder in the rhythm of the circulatory cycle increases in nurses after increasing the speed of change the shift working.[20]

In a study that was conducted by Khazaei et al. on sleep disorders among nurses with shift working in hospitals of Iran, it was found that shift working causes to increase daily dysfunctions due to lack of sleep, increase the incidence of lack of sleep, and sleep apnea among the nurses. Furthermore, it was found in their study that sleep disorders among nurses can affect the health of patients and nurses.[21]

So far, various questionnaire methods have been used in various studies to investigate sleep disorder and severity of depression among employed people that in this regard, the questionnaire of Epworth, Pittsburgh, and Insomnia index has high efficiency and high-performance precision in this field.[22],[23],[24]

Considering the nurses' job nature to the necessity to work at night shift, and subsequently, increasing the probability of adverse health outcomes caused by it among this laborious stratum and as well as the failure to carry out a research study to investigate the physical and neuropsychological effects of night work in nurses in the Southern part of the Iran, this study aims to investigate the type and percentage of sleep disorders among nurses in the night shift, to provide the grounds for greater attention of scholars to its different angles and ultimately leads to provide satisfactory work conditions with minimum complications of sleep disorder among nurses.

   Materials and Methods Top

Study design

The present study is a cross-sectional (descriptive-analytic) study that it was performed to evaluate the prevalence of sleep disorder and their adverse health effects among nurses shift working in hospitals in the Larestan in South of Iran.


In this study, all nurses shift working in the studied hospitals were included in the study, and finally, 100 nurses entered the study according to the criteria including the study: work experience at least 1 year, lack of second job, nonaddiction to alcohol, no history of mental diseases, and no history of family sleep disorder.


In this study, the data collection was done through face-to-face interview and the tools used in this study included four questionnaires: (a) Researcher made questionnaire of demographic information of the nurses, (b) Pittsburgh Sleep Quality standard Index (PSQI), (c) Epworth standard questionnaire, and (d) Insomnia severity index (ISI) questionnaire. Demographic information of studied nurses such as age, gender, marital status, educational level, number of children, type of employment status, and number of night work shifts per week of nurse was collected using researcher made questionnaire of demographic information. It was addressed to cases such as sleep mental quality, required time duration to sleep, useful sleep duration, sleep disorder, daily dysfunction, and use of the sleep medications In the PSQI questionnaire, in the form of 19 questions. In this questionnaire, 19 questions are scored in a 4-point Likert scale from 0 to 3, so that the zero score indicates lack of sleep problem, the score 1 indicates medium problem in sleep, the score 2 indicates a serious problem in sleep, and a score 3 indicates a very serious problem in sleep. Furthermore, getting a total score of over 5 in the entire questionnaire means poor sleep quality. Data related to the sleeping status of people during doing daily works and in leisure time was collected using the Epworth questionnaire, in the form of 8 questions. In this questionnaire, according to the response of each section, a score is awarded to that part which ultimately determines the total score of the sleep pattern of nurses, so that scores <10 are sleepy, between 10 and 16 are very sleepy people and a score of more than 16 is dangerously sleepy. Needed information on the problem of sleeping, disorder in sleeping, very early awakening, satisfaction with their sleep patterns, and also creating the disorder in the person's life due to sleep problems was collected using the ISI questionnaire in the form of 7 questions that according to the numbers assigned to each question. The score of each nurse is determined (in the range of 0–28), which ultimately were classified in the four groups of no clinical significant insomnia (0–7), sub-threshold insomnia (14- 8), moderate clinical insomnia severity (15–21), and severely clinical insomnia (22–28).

Content and formal verification method based on the resources and opinion polls of the faculty members were used to determine the validity of information gathering tools. The internal consistency method was used to determine the reliability of PSQI, Epworth Standard index, and ISI. Cronbach's Alpha coefficient was calculated for PSQI, Epworth Standard index, and ISI equal to 83%, 87%, and 91%, respectively.

Ethical considerations

The study protocol and its ethical considerations were approved by the Applied Research Council and Ethics Committee of Larestan University of Medical Sciences (grant no. 139506). Permission was obtained from the hospital authorities, and the purpose of the study was explained to all participants and they all signed written informed consents before participation. They were also assured of the data confidentiality and all the questionnaires were kept anonymous.

Data analysis

Data obtained from this study were entered into SPSS version 16 software were provided of IBM Statistics support after collecting. Descriptive and analytical statistical tests such as one-way ANOVA, t-pair, independent t-test, Kruskal–Wallis, Chi-square, and Pearson correlation coefficient with a significant level of P ≤ 0.05 were used to achieve the study objectives.

   Results Top

Mean and standard deviation of age and work history of studied nurses was equal to 30.4 ± 7.5 and 7.4 ± 7.12, respectively. Separation of 100 studied nurses by gender was in the form of 49 female and 51 male. The minimum, average and maximum number of nurses in night shift working were 1, 2, and 7 shifts/week respectively. The demographic characteristics of the studied nurses have been shown in [Table 1].
Table 1: The demographic characteristics of studied nurses

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The results of this study showed that the mean and standard deviation of the required time for sleeping in studied nurses after going to bed was 40.1 ± 32.5 min. The mean and standard deviation of PSQI in nurses was equal to 6.52 ± 4.23. The results of this study showed that the sleep quality index of nurses in different units of the hospital is significantly different from each other (P = 0.04). In [Table 2], the results of the score of PSQI questionnaire of nurses have been shown to separate in their occupational unit in the hospital.
Table 2: The Pittsburgh Sleep Quality Index score of nurses in separation their occupational unit in the hospitals

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The results also showed that the index of sleep quality index related to 44% of nurses is in good range (<5), and it is in poor range (above 5) in 56% of them. The results showed that there is a significant difference between the mean scores of nurses' PSQI questionnaires in terms of their gender, so that the mean score in male and female is 7.3 and 4.8, respectively (P = 0.004).

The results related to the Epworth questionnaire in the present study specified that of nurses working in different parts of the hospital, 78.5% have had sleepiness, 16.5% very sleepiness, and 5% of them have had symptoms of dangerous sleepiness. The results showed that there is a significant difference between the score of the index of Epworth sleepiness in nurses in separation of their gender, so that the mean and standard deviation of the raw score of the Epworth questionnaire in studied male and female were 11.3 ± 4.9 and 6.4 ± 3.9, respectively (P = 0.02). The mean score of the Epworth questionnaire related to the nurses studied based on occupational unit and in separation of their gender have been shown in [Figure 1]. It was specified in the present study that there is a significant relationship between the number of nurses' night shift in the weekly and mean of the score of the Epworth questionnaire, so that the mean score of the Epworth questionnaire will also increase after increasing the number of night shift nurses in the week (R2 = 0.78).
Figure 1: The average of Epworth questionnaire score in nurses

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The results related to the ISI specified that 46.4% of the people have poor insomnia, 45% have below the threshold insomnia, and 8.6% of the studied nurses suffered from to poor insomnia. The results of the score of ISI revealed in separation the occupational unit of nurses that the highest level of insomnia is was related to the nurses in the surgery unit and the lowest score is for the nurses of the internal medicine unit (7.5 ± 4.3 and 13.3 ± 5.7, respectively). In [Figure 2], the mean score of the ISI has been shown in the separation of occupational unit of the nurses. The results of this study showed that gender differences do not have a significant effect on the score of the ISI of studied nurses' (P = 0.2). Furthermore, the results of this study showed that the mean of ISI score of nurses increases by increasing the number of nursing night shift working of nurses per week (R2 = 0.76). The results related to the evaluation the variables of ISI questionnaire showed that 76.4% of the nurses had problem in sleeping, 59.4% of them had problem in staying sleeping and 63.8% of them had problem in early waking up. It was also found that 91.3% of the studied nurses are dissatisfied with their sleep pattern and 82.6% of them believed that the existence of sleep problem has interrupted their daily performance.
Figure 2: The average of insomnia severity index questionnaire score in nurses based on their occupational unit

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   Discussion Top

Shift working can reduce sleep quality and cause sleep disorders among employees.[25] The results of this study showed that increasing rate of night shift among nurse's causes to increase the incidence of sleep disorders and decrease their sleep quality.

The results of the PSQI showed that 56% of the studied nurses have poor sleep quality (score above 5). In this regard, it was specified in a study by Gómez-García et al. in Spain that PSOI score in nurses with night work shift is equal 6.8 (as the poor quality range), this score is considerably less among nurses with day work shift.[26] Work rotation or shift working on different days of the week, greatly causes to the prevalence of sleep disorders. As a result, workers such as nurses have a feeling of sleepiness and discomfort in their work environment, which causes to reduce the quality of service delivering to patients and increase the risk of occurrences the occupational errors. Considering the need for nurses' night attendance in hospital environments, these employees will have to enter the shift working program, so hospital administrators must consider the guidelines and limits for the high number of night work shifts of nurses per week to minimize the adverse health effects of shift working.

As it was shown in the results part of the study, the poor sleep quality and the highest score for the PSQI questionnaire were reported by the surgery unit nurses (11.5) [Table 2], which this can be due to high occupational stress of this unit that high work stress causes to increased fatigue and ultimately, the need for rest goes high and following by the lack of compensation this work-related fatigue, causes the adverse health effects such as the high prevalence of sleep disorders in night work shift nurses in stressful units than other parts of the hospital. In the same regard, it was specified in the study of Eldevik et al. that increasing fatigue and work stress in nurses causes to reduce their sleep quality.[20] Furthermore, the results of this study showed that the level of sleep quality in female nurses is significantly less than men, which could be due to the weaker body structure of women's body and the sensitivity of the women's psychological structure than men.

Based on the results of the Epworth questionnaire, it was specified that there is one of the sleepiness symptoms in all studied nurses during doing their daily routine or their leisure time, which indicates the presence of sleep disorders in the studied nurses. Based on a study done by Flo et al. that was conducted on 1968 nurses, the results of the Epworth questionnaire indicate the existence of severe sleep disorders in 40% of nurses, which had had a direct relationship with the changing the shift program and the number of shift working at nights.[9] As it was shown in [Figure 2], the mean of raw score in female nurses is much higher than male nurses. Which can be attributed to the higher activity of women at home than men and thus reducing the time that they rest at home. The results of this study showed that the highest score of the Epworth questionnaire is related to the nurses of the surgery unit that was consistent with the results of the PSQI questionnaire.

The results of the survey on the Epworth questionnaire showed that after increasing the number of nurses' night shifts working in the week, the score of Epworth questionnaire and consequently sleep disorders was increased (R2 = 0.78). In a study conducted by Zhen Lu et al., was showed that there is a significant and linear relationship between change rate and number of shifts work and disorders rate (P < 0.001), anxiety (P < 0.001), depression (P < 0.002), and physical pain (P < 0.001) of nurses.[27] Furthermore, it was found that after increasing nurses' night shift working, their job performance has reduced significantly and the incidence of cardiovascular disorders among them has increased in the study of Asaoka et al. on nurses in Japan.[28]

The results of the ISI questionnaire showed that more than 55% of studied nurses suffered from to moderate-to-very high levels of insomnia that could be a danger alarm to nursing society to act of preventing the effects of insomnia on the health of nurses and improving the quality of service delivering to patients. In this regard, in a study conducted by Yazdi et al. on the nurses of Qazvin hospitals, it was found that the prevalence of insomnia among 160 nurses is high.[29] It was specified in the results of this study, that there is a linear and direct relationship between sleepless severity of nurses and the number of nursing shift working, so that the severity of insomnia in nurses increases (R2 = 0.76) with the increase in the number of shifts working in nurses per week. Similarly, it was specified in the study of Yazdi et al. that the number of nurses' night shift working had a significant effect on insomnia severity of nurses (P < 0.05).[29] Among the common problems of nurses, we can mention problems with sleeping, problem in staying sleeping, irregular sleep pattern, and problem in enjoying a deep sleep that these problems are considered of the most common problems in people with sleep disorders and shift working. The physiological function and rhythm of the body's circulatory system will change by working in hours outside the design window (between 7 and 16 a day), which will disrupt the secretion of body hormones, in particular, the cortisol and aldosterone enzymes (enzymes that regulate sleep and awakening of humans are secreted from the adrenal and pineal glands, respectively) and ultimately leads to sleep disorders and other adverse health effects in shift workers, especially nurses.[30]

   Conclusions Top

Finally, it can be concluded that sleep problems are high among nurses working in night work shift. There is a direct and linear relationship between the number of night shift working in a week and prevalence the sleep disorders such as poor quality of sleep, sleepiness in doing daily acts and leisure time, severity of insomnia, problem of sleeping, problem of staying in sleep, disorder in sleep pattern, and sleep mental dissatisfaction among nurses. Among nurses working in high-stressed units of the hospital such as surgery unit, the prevalence of sleep disorders is higher than other nurses. Regarding the results of this study, to reduce the sleep disorders, reduce occupational error, promote the health level of the hardworking nurses of community, and increase the quality of service delivering to patients hospitalized in the hospital as a vulnerable corps of the community, it is recommended that officials of nurses community and managers of hospitals put some needed solutions to reduce and control the number of night shift working of nurses in the working week in their agenda.

Financial support and sponsorship

The current study was financially supported by Larestan School of Medical Sciences, Larestan, Iran.

Conflicts of interest

There are no conflicts of interest.

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Correspondence Address:
Asst. Prof. Razieh Zolghadr
Department of Public Health, Ewaz School of Health, Larestan University of Medical Sciences, Larestan
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1735-5362.272535

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