Sleep quality and common mental disorder in the hospital Nursing team

Objective: to determine the prevalence of sleep quality and common mental disorder in Nursing professionals and factors associated with sleep change. Method: a cross-sectional, analytical and quantitative study developed with 196 Nursing professionals of a public hospital and a mixed one. Data was collected by means of an instrument of sociodemographic characterization, by the Self-Report Questionnaire 20 and Pittsburgh Sleep Quality Index and were analyzed by descriptive and inferential statistics to identify possible factors associated with sleep changes. Results: sleep changes were identified among the Nursing professionals with a frequency of 76.5% (70.4-82.1). Sleep quality was classified as poor in 41.8% (41.8-55.6) and sleep disorder in 27.6%. (21.4-34.2). The prevalence of common mental disorder was identified in 36.7% (30.1-43.9). The main factor for poor sleep quality was the presence of common mental disorder (Odds Ratio: 5.15; p<0.001). Conclusion: sleep changes were prevalent and the characteristics of the work environment and the presence of mental disorder showed relevance in the changes.

With an organizational method of data collection, it was chosen to divide the instruments into blocks, the first being a questionnaire composed of sixteen closed questions that contemplated the sociodemographic and occupation data elaborated by the researchers, according to the national and international literature. The studied variables were age, gender, schooling, marital status, self-referred skin color, family income, professional category, work period, academic training, time working in the profession and at the institution, if they had more than one job, and weekly working hours. A pilot test was carried out to clarify possible doubts, making the instrument available to 5 Nursing professionals of each institution, from various units. There was no need to adapt the survey questionnaire and the pilot test respondents were excluded from the final sample.
As for the second block, it aimed to assess mental health, in which the SRQ-20 (Self-Report Questionnaire) Mental Disorders Assessment Questionnaire was used, validated in Brazil in 1986, which is composed of 20 questions divided into characteristic symptoms of  (Table 2). However, only one of the three variables presented statistical significance: common mental disorder. Thus, the Nursing professionals who were classified with CMD presented a 5 times higher probability of sleep changes (p-value<0.001).  CMD and sleep quality (17) .
In this study, it was verified that the characteristics of the Nursing professionals are similar to those of other research studies in Brazilian hospital units (1,7,9,18) . These data were also observed in a study developed in a university hospital in the state of Minas Gerais, where 87.9% of the professionals were women, with a mean age of 40.2 years old (19) . Another study conducted with Nursing technicians in Montes Claros, Minas Gerais, indicated that 58.6% were female, with a mean age of 38.5 years old (20) . A study developed with 540 nurses in 6 hospital institutions in Iran found that 66.3% were women with a mean age of 32 years old (11) , data similar to those in this research.
In relation to income, most of the professionals reported earning from three to five minimum wages, having only one job and working up to 40 hours during the week, which is similar to a research study carried out in the North of Paraná (Brazil), in which professionals had only one job (56.7%) and earned from one to two minimum wages (7) . Likewise, another study developed in China, with nurses working in different hospital units, presented 4,185 female professionals, with only one job and who worked up to 45 weekly hours (21) .
It is to be noted that 66.8% of the professionals had employment contracts after passing a public tender, similarly to the National Research of the Nursing Profile, which indicated 65.3% of the Brazilian professionals working in this service (18) . However, the type of contract tends to vary according to the economic scenario of each region, as a study conducted in the Northeast of Brazil found that service provision was the main hiring method (1) .
It was also observed that 76.5% of the  (21) . This finding is similar to the study conducted in India, which obtained 83.2% of the nurses as with poor sleep (10) .
However, a research study developed in a hospital service in Colombia pointed out only 24.9% of the professionals with sleep changes, despite sleeping less than 7 hours a day (24) .
As for a study carried in hospital from the city of Larestan, in the South of Iran, to assess the prevalence and consequence of sleep changes in nurses, it obtained a mean score of 6.52 ± 4.23 in the sleep quality index.
And, according to this index, 56% of the nurses were classified as with poor sleep; therefore, 78.5% were sleepy, 16.5% very sleepy and 5% severely sleepy during labor activities. In addition, the sleep disorders in the professionals who worked in the surgical section were higher than those in the nurses from other hospital units (p<0.05) (25) .
Another study conducted with nurses in the South of Italy has found that women presented worse sleep quality when compared to men, in addition to having less social support at work, which was negatively associated with sleep disorders (26) , while a study carried to assess the prevalence and other factors associated with sleep disorder in nurses (n=422) who work in federal government hospitals in Ethiopia, in Adis Abeba, obtained 41.8% of the participants with sleep changes, especially insomnia, in which work in threeshift rotations, (adjusted OR = 3.1, 95% CI: 1.68 to 5.83) was significantly associated with sleep disorder (27) .
These differences in the sleep classification using the same research instruments are associated with lifestyle, workload, the physiological stress of each individual (28) , gender, age, presence of children, the personality of each professional and the economic conditions of the country (1) . In addition to that, the exposure to environmental factors and to work dynamics with high workload and stress is associated with the development of sleep changes (3,5,11,19) .
Among the work-associated psychic disorders, CMD develops in different populations, especially in the professions that presented great requirements in the tasks fulfilled (24) . This study identified a CMD global prevalence of 36.7%, similar to a study conducted in a public hospital in the state of Bahia (Brazil), which found 35% of the Nursing professionals with CMD (6) , as well as Rev. Latino-Am. Enfermagem 2021;29:e3444.
in a research study carried out in a psychiatric hospital with the Nursing team, which obtained 25.7% as suspected cases (29) .
In a study conducted with nursing technicians in a university hospital in the state of Minas Gerais (Brazil), a CMD prevalence of 46.9% was observed (20) .
High rates of mental disorders are worrisome in the hospital environment, as they have direct implications on the quality of the care provided to the patients under the Nursing team responsibility (29) .
As for the factors associated with sleep changes, the Nursing professionals who were classified with CMD had five times more probabilities of having poor sleep.
This fact corroborates a meta-analysis carried out on sleep dissatisfaction and the development of psychic disorders, which found a strong relationship between insomnia and mental changes, including depression, anxiety and suicidal ideation (30) .
In a study conducted only with women, the association between CMD and shorter sleep duration was also obtained, pointing out that these changes are the first symptoms detected in psychic disorders. It is highlighted that the women who reported sleeping six hours or less presented 2.66 more chances of CMD when compared to those who slept more than seven hours (31) .
A research study conducted with Chinese nurses also obtained an association between the presence of anxiety signs (OR = 8.07, IC 95%: 2.92-22.33) and poor sleep quality, long latency and insomnia (32) .
Likewise, a study also conducted in China with 1,500 nurses in six hospitals from the Shandong province associated the existence of depression symptoms with the presence of sleep disorders and, consequently, with lesser control of the work environment. Nurses are susceptible to the development of work-related mental disorders, thus impairing the quality of the care provided (21) .
It is also asserted that exposure to stress and poor sleep quality also relate to cognitive failures, such as memory errors, perception, planning, performance of tasks that occur on a daily basis and service provision (33)(34) . These data are relevant because, in this study, most of the participants were women and reported sleeping 6.5 hours, which can contribute to accidents and risk behaviors. In the context of Nursing, this fact can cause mistakes in the assistance offered, as well as in harms to the patient and the institution.  presented poor sleep quality in the final classification of the instrument (24) . It is emphasized that the better assessment can be related to the adaptation to the practice of the service, to working in shifts and to poor quality of sleep as the routine of the activities performed.
As for the type of hospital, in the Brazilian reality, the public institutions face difficult situations, such as insufficient material, and human resources and equipment, lack of beds and overcrowding in the services, which many times lead to professional illnesses (35) . In addition to that, despite the improvement in the quality and quantity of the health services, the pattern centered on primary and emergency care overloads the hospital services with high work demands (36) . These situations impose limitations to the competence and freedom of the professionals, since they are subjected to stress, suffering and poor working condition, with the objective of performing quality health care (35) , at the same time that they have stability as a factor that keeps them in the same employment contract.

In another study conducted in public hospitals in
China, presence of poor sleep quality among nurses was obtained, with 68.8% of those that worked in high-complexity tertiary institutions presenting severe sleep disorders associated with great service demand, a greater number of patients to care of in the night shift and absence of recognition of the work performed (21) .  (23) . A research study conducted in Sweden with newly graduated nurses obtained presence of sleep changes related to the concerns and persistent thoughts about work, in addition to a high load of activities (28) .
An integrative literature review study on the current knowledge and attitudes in relation to the impact of sleep disorders on health and on the cognitive functions among the Nursing team members in Europe showed that 30% to 70% of the nurses sleep less than six hours before the shift. Regarding the cognitive effects of sleep deprivation, it was observed that it impairs the performance of tasks that require prolonged and intensive attention, which increases the number of errors when serving the patient (37) .
It is also highlighted that the night shift, both with fixed and alternate working hours, is harmful to the professionals' health, as it alters the productions of melatonin (38) , reduces work safety, productivity, performance and quality of life (39) , being related to gastrointestinal problems, pain in the back and neck, fatigue, depression, tiredness, stress, cardiovascular diseases and early mortality (4,31) . In addition, the 12hour working day followed by 36 hours of rest makes it easier for the employee to have a second job (23) .
Having more than one employment contract generates extensive working days, with partial or nonexistent rest, which favors poor sleep quality.
In addition to that, with longer time working at the hospital institution, the development of skillful care is observed; however, with the professional experience, there is longer time of exposure to occupational stressors, which facilitates the development of sleep disorders (22,24) and can wrongly contribute to reducing the perception of the need for protection against accidents and the understanding about one's own health status (35) .
Sleep latency is assessed by the time needed to fall asleep, from the wakefulness stage to total sleep and, in this study, statistical significance was observed with having a job (p-value<0.001) and longer working time (p-value = 0.001). In addition to that, the mean time to fall asleep referred was 31.9 minutes, with a mean of 6.5 sleep hours. In a research study conducted in São Paulo (Brazil), it was found that 35.29% of the professionals reported needing more than 30 minutes to fall asleep (23) , as well as in study carried out in China, which obtained a higher latency among the professionals (40) and a research study conducted in Colombia, in which 34% of the professionals needed more than 28 minutes to fall asleep (24) .
It is also known that sleep is influenced by hemodynamic conditions, temperature, environmental sounds, social activities and exposure to light. The latter has an important effect on the initiation and maintenance of this process, since artificial light alters the circadian and sleep-wake cycles (41) .
Furthermore, a study shows that there is large exposure to artificial light in the general population, with a constant increase in the last years, which, along with the environmental working factors, influences sleep quality (31) . It is suggested that the professionals with a job expose themselves more to artificial light during their leisure time, which, together with work exposure, contribute to difficulty in falling asleep.
In this study, statistical significance between the working shift and sleep duration was observed (p-value<0.001), in which the period of the day demonstrated higher mean points, suggesting that these professionals present fewer resting hours.
It is also pointed out that the anxiety and stress levels have an effect on the sleep assessment tool, as well as on the quality and duration of the physiological process. In this way, professionals of the day shift present more accentuated work routines, which contributes to more frequent awakenings at night, insomnia and less sleep time (35) .
The usual effectiveness of sleep is assessed in the question on how many hours were slept in relation to the time in bed, with white skin color (p-value = 0.010), two or more jobs (p-value = 0.040) and more than 40 working hours (p-value = 0.030) presenting higher mean scores in this study.
It is also pertinent to state that, despite the economic growth of the Nursing profession, the submission to long working hours and the duplicity of jobs are similar to the medical profession, which intensifies the risk of illnesses, dissatisfaction with sleep and insomnia (43) . A study carried out in China with physicians and nurses found that the workers presented very different sociodemographic and occupational characteristics and that the nurses had significantly greater mental health problems and sleep changes than the other workers (42) .
It is also contemplated that, in case of more than one employment contract and extensive workloads, the time devoted to sleep becomes scarce, the secretion of cortisol and the central temperature of the organism increase, with a reduction of melatonin and a consequent Rev. Latino-Am. Enfermagem 2021;29:e3444.
Regarding the long working days, they were also observed in a study developed with nurses from  (46) . As for a study carried out in Colombia, it was found that only 4.1% of the professionals used sleep medications (24) , similarly to another research study with nurses from Ethiopia, in which 24.6% of the participants made use of some medication to improve sleep quality (27) .
It is contemplated that the professionals justify taking a medication due to stress, excessive workload, poor working conditions and poor sleep quality. In addition, self-medication is considered a phenomenon that occurs more frequently among women, with high schooling and with facilitated access to the drugs (27,46) , a profile similar to the Brazilian.
As for the daytime dysfunction component, assessed by the question on remaining awake in routine tasks and excited to carry out the activities, a statistical significance with the hospital variable (p-value = 0.010) was observed, with a higher value for the public institution, suggesting greater sleepiness during the day in the professionals from the public service and poor subjective sleep quality.
Regarding the limitations of this research, the cross-sectional design stands out, which prevents data generalization and the monitoring of the changes developed by the professionals, as well as the non-investigation of the individuals away from work. In addition to that, it was not the objective of the study to assess the rest conditions and social support in the work environment, variables that can influence the development of mental disorders and sleep changes.
It is also noted that the sample was mostly composed of nursing technicians, as well that the instruments are self-applied and were made available to the participants for completion, with return scheduled at a later date.
Such criteria can contribute to bias, perhaps affected by the interest and attitudes of the research participants.

Conclusion
A priori, it is contemplated that poor sleep quality and sleep disorder were prevalent in the sample and, when the sociodemographic variables were observed, the presence of common mental disorder showed to be a factor associated with sleep changes. In addition to that, among the sociodemographic and occupational data, the public hospital, being female, white skin color, having a job, working more than forty hours a week, longer working time in the institution, and the night shift showed an association with the assessment of sleep quality.