Occupational stress and self-rated health among nurses

Objective: To analyze the association between job stress and self-rated health among nurses in public hospital emergency units. Methods: This is a cross-sectional study undertaken through the administration of a self-administered questionnaire in a sample of 134 health professionals, using the brief version of the Job Stress Scale. Descriptive analyses of the socio-demographic, health and work variables were undertaken, as was multivariate analysis through unconditional logistic regression for adjustment of the association between job stress and poor self-rated health, in accordance with potential confounding variables, with a level of significance of 5%. Results: 70% of the interviewees were classified as passive workers or as with high strain. Poor self-rated health was significantly greater among health professionals with high demand and low control, compared to those with low strain, after adjusting for co-variables. Conclusions: Low control, allied with low demand, can serve as a demotivating factor, contributing to the increase in professional dissatisfaction. It is recommended that institutions should adopt a policy of planning and managing human resources so as to encourage the participation of health professionals in decision-making, with a view to reducing job stress among nurses.


Introduction
Work performs an important role in individuals' social lives, providing the support of a regular income, opportunities and personal growth, social identity and self-esteem, but can have consequences for the worker's health.

Various
approaches have been developed for evaluating the impact of workplace stress on health (1)(2) .These include the demand/control model, which emphasizes that the imbalance between the psychological demands and the control over the process results in strain and loss of skills and interest, affecting the worker's health (3) .
Self-rated health is increasingly-used as an indicator in Brazilian and international epidemiological studies as a proxy for the "real" or "objective" state of health, and consistently predicts the individual's mortality and decline in functional health.Various studies have shown the association between socioeconomic condition and the presence of chronic illnesses with self-rated health, but few have considered work conditions in this relationship (4)(5)(6)(7) .It is necessary, therefore, to investigate how relationships between staff and staff, and between staff and the work environment influence the health-illness process, incorporating the worker's point of view.This study's objective is to analyze the association between job stress, using the Job Stress Scale, and selfrating of health among nursing staff in public hospital emergency units.

Methods
This cross-sectional study was carried out in 2010 in the city of Campo Grande, capital of the state of Mato Grosso do Sul.The study's target population was made up of 169 health professionals from the nursing team (registered nurses, nurse technicians, nurse assistants), of both sexes, belonging to the workforce of nine public health units which attend emergency cases 24 hours/ day.Employees seconded to other institutions and those on leave of absence for non-health-related or healthrelated reasons for over six months were excluded.The study's final population was made up of 134 nursing personnel.
A self-administered questionnaire was used, provided in individualized and sealed envelopes.These were filled out during work hours in the workplace, after the signing of the Terms of Free and Informed Consent.
They addressed socio-demographic, health and work matters, and included questions about job stress, based on the concept of demand/control found in the brief version of the Job Stress Scale, previously translated and validated for Brazil (4) .
The JSS scores were obtained by summing the points attributed to each of the questions in each dimension (5 questions for the 'demand' dimension, and

Results
The distribution of the 134 participants by professional category revealed that 12 (9.0%)were nurse assistants, 21 (15.7%) were registered nurses and 101 (75.4%) were nurse technicians.In relation to the characteristics of the study population, (Table 1), the majority were female (69.9%), aged below 35 (40.2%),Caucasian (61.2) and had a per capita family income of less than 1.5 minimum salaries (MS) (53.9%).
It was observed that the majority of the workers had completed senior high school (71.6%), resulting from the composition of the study population itself, and that among the nurse technicians and nurse assistants, 66.7% had completed university.
Concerning the characteristics related to health, just over half of the workers (55.2%) stated that they had not been medically diagnosed with a chronic illness.
Table 3 shows that statistically-significant differences were not observed between the socio-demographic variables and self-rating of health.However, this is worse among those with a chronic illness.(p=0.000).In relation to the work variables, the behavior was fairly similar between the various categories, whether time in the institution, years doing on-call night shifts or extra hours doing on-call shifts per week, with a positive self-rating of health predominating.
However, the workers who were satisfied with work and health, and who mentioned high social support, presented significantly better evaluations of their own health.
The variables 'diagnosis of chronic illness', 'satisfaction with work' and 'social support' were associated as much with exposure (job stress) as with the outcome (self-rated health) with significance of less than 10% in the bivariate analysis, and were selected for the adjustment of the multivariate model.
The variable 'age' was included, even though it did not present statistical significance, due to its relationship with both self-rated health and job stress, as described in the literature.In the various multivariate models analyzed, not adjusted and controlling for the confounding variables, it was observed, systematically, that the workers submitted to all types of job stress, when compared with those with low strain or "relaxed", had higher chances of poor self-rated health (

Discussion
The influence on health of psycho-social factors and of the organization of work has increasingly been the object of study, given the recognition of its relationships with workers' well-being and quality of life.Studies with distinct methodological approaches and among widely differing occupations have consistently revealed the association of the worst conditions of work with physical and emotional symptoms and health in general (8)(9)(10)(11) .
Among nursing personnel in particular, different factors are related to occupational stress, including overloading of work, conflicts in the work environment, ambiguity in carrying out tasks, failure to recognize skills, and experiences of aggression, all of which have direct effects on physical and mental health (12) .
Various scales are currently used for evaluating occupational stress, with that based in the demand-control model (1) and the effort-reward model (13) standing out.
Although using different approaches, both show a positive association between occupational stress and various health events, particularly among nursing staff (14)(15) .
In this study, the authors used the demand-control methodology (1) , which has as its theoretical assumption that the work undertaken in conditions of low control and high demand (high strain) and low control and low demand (passive work) is prejudicial to health.
In agreement with this theory, the present study's results indicated a positive association between highlydemanding work and a worse evaluation of health, even after adjusting for the confounding variables.
A study carried out among nurses in the city of Rio de Janeiro tested the two models for their ability to measure occupational stress, and its results showed that, irrespective of the model used, a strong association was observed between self-rated health and job stress (15) .
Similarly, research undertaken with nurses in a large Chinese city showed strong predictive power for both models with high levels of burnout (16) .
Exposure to more detrimental levels of stress, with a higher proportion of high strain and passive work, indicates that the majority of professionals investigated were at risk of falling ill as a result of their occupational situation.
In the present study, the variables which were most directly related to work characteristics, such as time in the institution or undertaking on-call shifts, were not associated with job stress, nor with worse self-rating of health -a fact also reported in a study of nurses in Greece (17) .The most important factors in explaining the association of interest were dissatisfaction with work and low social support.The impact of low social support on the triggering of stress at work, along with its repercussions on health, has already been demonstrated in a study of nurses in a hospital in the south of Brazil, indicating the importance of a harmonious working environment in the prevention of occupational stress (18) .
Work satisfaction is among the factors indicated as reducing occupational stress, being a determinant for a worker remaining in the job, for lower staff turnover and lower institutional costs, also ensuring better performance of activities (19) .A study on job stress among Rev. Latino-Am.Enfermagem 2013 Mar.-Apr.;21(2):475-83.
nurses in emergency units in a hospital in Spain also observed that the greater the satisfaction with work, the better the perception of one's own health (20) .
Among the main motivational factors in the nurse's work, the following stand out: liking what one does, offering quality care, having a good multiprofessional relationship, having the possibility of professional growth, having the power to resolve issues, and the work conditions themselves (21)(22) .Thus, in situations of low autonomy and support in the face of decisions made, the impact of stressing factors on health becomes high.Increase of control over work has direct and indirect positive effects on the worker's health, being associated with better evaluation of health and lower levels of stress (23) .
The authors believe that the present work contributes by reinforcing the findings of other research previously cited (18)(19)(20) on the importance of satisfaction Another factor which must be taken into account is that the 'self-rated health' variable may be influenced with work and of social support in preventing occupational stress.The results found show that the work management model used in the institutions studied may have a determinant role in the high levels of stress detected, and that these findings may be extrapolated to other public health institutions with the same type of attendance.It therefore becomes necessary to discuss the nursing team's working conditions in the emergency units, so as to implement actions aimed at preventing or minimizing the problems found.The authors believe that effective measures must include not only individual strategies for changing behavior, but also, and principally, organizational changes aimed at permitting greater satisfaction in the work environment.For this reason the authors detect the need for intervention in three distinct areas: professional training, renewal of organizational models, and on-going monitoring of work satisfaction.Finally, the authors highlight some of this research's limitations.Because it is a cross-sectional study it shows a snapshot both of the exposure and the outcome, which situation is especially relevant in the case of occupational studies, as a result of the Healthy Worker Effect, which may provide an image which is excessively positive in relationship to the reality.It was sought to minimize systematic errors of selection through the inclusion of all the nursing staff working in the emergency units, plus those on leave due to illness for less than six months.
by memory bias or by socially-acceptable responses.The decision to use a self-administered questionnaire was taken with the aim of minimizing the effects of the latter.In spite of the limitations imposed by the study's design, the results were shown to be coherent with the literature, showing the importance of work conditions for nursing personnel's health situations.ConclusionsThis study demonstrated the importance of factors related to the working environment as potential sources of job stress among nurses.Individual characteristics were less expressive in explaining the phenomenon.It is concluded that low control, allied with low demand, can be a discouraging factor, contributing to professional dissatisfaction.The development of an effective policy for planning and managing human resources, encouraging the health professionals' participation in decisions, can contribute to reducing stress at work, with an increase in the general effectiveness of the health system and improvement in results -both for those providing the assistance and for the service users.
however, half mentioned low social support (51.1%).In relation to the characteristics related to the demand and control dimensions, the majority of workers had low demand at work (57.5%) and low control (70.1%), constituting the majority of passive workers (38.1%).whomentionedmoretime doing on-call night shifts and extra weekly on-call hours, irrespective of hours worked, there was a significant association with passive work.Dissatisfaction with the work and low social supportwere associated with high strain at work, but significant differences among the categories of occupational stress were not observed relating to satisfaction with life.

Table 2 -
Socio-demographic health-and work-related characteristics of the nursing personnel in the emergency units according to quadrants of Karasek Job Stress Scale -Campo Grande, Mato Grosso do Sul, Brazil, 2010 (continue...) www.eerp.usp.br/rlae

Table 4
).Despite the strength of the positive association found between outcome and exposure in the four models analyzed, only those workers submitted to high strain showed significantly different values.Although a reduction in the strength of the association is observed with the introduction of controlled by the variable 'social support', reduced the strength of the association for all of the categories of exposure, and, despite maintaining a strong association (OR=4.303)with work with high strain, lost statistical significance.

Table 4 -
Association between negative self-rated health and job stress, among nursing personnel in the emergency units -Campo Grande, Mato Grosso do Sul, Brazil, 2010