View source for Effort-Reward-Imbalance


==  Abstract ==


In 1986, Johannes Siegrist, a medical sociologist and university professor, designed the Effort-Reward-Imbalance Model to predict and explain the effects of high effort with low return on the health of the heart <ref name="vanvegchel2005"/>. This model has been further developed over the years and is used today to understand the effects of work on the health of the employee, in order to ideally prevent diseases. The model is designed to assess negative effects and stressful experiences at work and predict probabilities of illness. This imbalance can lead to a range of health problems such as stress, burnout, and depression <ref name="Siegrist1996"/>. Three primary hypotheses can be derived from the ERI model. First, the external ERI hypothesis, which states that high effort combined with low reward increases the risk of poor health. Second, the internal overload hypothesis can be derived from the model. The core message of this hypothesis is that a high, critical level of overcommitment also increases the risk of deteriorating health. These two hypotheses are ideally rounded out with the interaction hypothesis, which suggests that it is primarily the combination of too much effort combined with low reward and the assumption of too much obligation in the form of overcommitment that leads to an even higher risk of stress reactions <ref name="peter2002"/>. The topic is becoming increasingly relevant in the field of employee leadership and project management. Project managers and general managers must become aware of the dangers of the imbalance of effort and return in order to generate possible implications for their work and leadership. 

This article reviews the structure and idea of the model, the hypotheses, the methodology, the impact on health, possible limitations and project management implications.

== Structure and idea of the model ==

The goal of the model is to combine sociological information describing the work environment or setting, psychological information describing relevant person characteristics, and biological information describing immediate or long-term health outcomes. The model addresses the challenge of answering the question of what critical components of work life influence human health <ref name="Siegrist1996"/>. It is composed of three components, "effort," "reward," and "overcommitment," although "Overcommitment" was first added to the model in 1999 (see figure 1).

The effort is described in the model as the employee's obligation to the employer <ref name="vanvegchel2005"/>. The concept of high effort can be divided into high extrinsic effort and high intrinsic effort. Extrinsic effort is the caused stress from outside, for example, in the form of work pressure or the general demands of the job. The high intrinsic effort defines above all the need for control, or the own motivation in a demanding work situation. Reward is described in the Effort-Reward-Imbalance model as professional reward in the form of money, appreciation and state control. In the model, the concept of state control, i.e., control over one's own occupational own professional status, is highly relevant. This includes the availability of advancement opportunities and job security. The combination of these two conditions of low reward coupled with high effort can have negative effects on various areas of job satisfaction, but especially on health.


[[File:ERI model.jpg|400px|thumb|center|figure 1: own illustration of the ERI Model]]

== Hypotheses ==

Three primary hypotheses can be derived from the ERI model. First, the external ERI hypothesis, which states that high effort combined with low reward increases the risk of poor health. Second, the internal overload hypothesis can be derived from the model. The core message of this hypothesis is that a high, critical level of overcommitment also increases the risk of a deteriorating health state. These two hypotheses are ideally rounded out with the interaction hypothesis, which suggests that it is primarily the combination of too much effort combined with low reward and the assumption of too much obligation in the form of overcommitment that leads to an even higher risk of stress reactions <ref name="peter2002"/>.

== Methodology used in project management ==

Since 1996, the Effort-Reward-Imbalance-Questionnaire has typically been used to determine the imbalance between effort and reward. In practice, this questionnaire is also used in the context of general management activities and project management tasks to determine the stress level of team members in a project <ref name="vanvegchel2005"/>. The questionnaire designed by Siegrist measures extrinsic effort, reward, and overcommitment, the three components of the ERI model. Extrinsic effort is measured using a scale consisting of six items related to the demanding aspects of the work environment <ref name="stanhope2017"/>. For example, project members are asked if the worker is under constant time pressure due to a heavy workload. If the participant answers in the affirmative, the participant is then asked to rate the severity of this situation on a Likert scale. By asking questions of this type, it is possible for the project manager to better manage the workload of his or her employees <ref name="hanson2000"/>. Other items measuring extrinsic effort include physical workload, potential interruptions, level of responsibility, number of overtime hours, and increasing demand. The Reward Scale consists of 12 items that include two subscales, appreciation and status control.

The esteem scale contains five items, for example, the subjectively perceived respect that employees receive from their colleagues and managers. Status control is measured with six items, including the item of opportunity for promotion <ref name="hanson2000"/>). The operationalization of overcommitment has changed repeatedly over the years. The most modern versions of the questionnaire contain 5 items designed to measure the employee's ability to switch off from work after a day's work. The ability to switch off from work was declared to be the most important item <ref name="niedhammer2000"/>. Another item measures the participant's irritability.
For each item, a minimum score of 1 and a maximum score of 4 must be achieved. To identify Effort-Reward Imbalance, the ratio is calculated as follows:<math>ER=k*(E/R)</math> with <math>E</math> for Effort, <math>R</math> for Reward, and <math>k</math> as a corrective variable with <math>k=7/3</math>. An imbalance exists if <math>ER</math> is not equal to 1. When the value of <math>ER</math> is less than -1, it indicates an imbalance in favor of reward and when <math>ER</math> is greater than 1, it indicates an imbalance in favor of effort <ref name="stanhope2017"/>.
As a project manager, its common to use these results to rethink one's behavior toward team members in a project in terms of whether to increase reward or decrease effort.

== Impact on health ==

Health effects can be divided into physiological, mental, physical, and behavioral. A meta-analysis by Faragher et al. from 2005 provides a systematic review from 485 studies with a total size of 267,995 study participants on job satisfaction and consequences on health. The calculation yields a combined overall correlation of job satisfaction and health of r=0.370. Accordingly, a valid positive correlation exists <ref name="faragher2003"/>. The model describes that health consequences can arise from persistent stress reactions. Factors that have a high probability of triggering a stress response are called stressors and play an important role in the relationship of the ERI model and the health of the worker <ref name="greif1991"/>. The consequences of stress reactions and stress differ on the temporal and content levels. On the one hand, short-term consequences exist, such as fatigue, monotony, or satiety, however, on the other hand, there are numerous possible medium- to long-term consequences, such as depression. On the content level, the consequences of stress on health differ between the physiological, psychological, physical and behavioral levels (see figure 2, <ref name="kauffeld2019"/>). As a project manager, it is useful to be aware of the impact of effort-reward imbalance on health in order to generate implications for your own work and people management.


[[File:Levels and consequences.jpg|400px|thumb|center|figure 2: own illustration of levels and consequences of ERI]]

=== Psychological/psychosomatic health effects  ===

An imbalance of effort and reward can have negative influences on the psychological well-being of the individual. An example of this is a study in the Japanese nursing system from 2017, in which 17.9% of the 173 study participants stated that they suffered from high psychological stress. The Effort-Reward-Imbalance-Questionnaire was used as the survey baseline in the study <ref name="honda2017"/>. Two of the most common psychological stress disorders are burnout and depression. These psychological and psychosomatic health consequences are also relevant for project managers, as a possible long absence of the affected employee should be prevented.

==== Depression ====

The number of people currently suffering from depression is high.
The German Depression Aid Foundation has determined that 11.3% of women and 5.1% of men in Germany suffer from depression. In terms of their severity, depression is one of the most underestimated diseases <ref name="stiftung2016"/>. 
2015, more people died by suicide (10,080) caused by depression in Germany than by drugs (1,226), traffic accidents (3,578), and HIV (371) combined <ref name="statistisches2015"/>. Depression is expressed in the form of impaired mood, as feelings of dejection, anxiety, loss of pleasure, emotional emptiness, lack of drive, loss of interest, and numerous physical complaints <ref name="hautzinger2010"/>. Faragher et al's meta-analysis of 485 studies and 267,995 study participants calculated the correlation of job satisfaction and depression.
The correlation is positive and is <math>r=0.366</math>. Accordingly, there is a positive relationship between job satisfaction and depression.  The meta-analysis makes it clear that employees who are subjectively lower in the hierarchy of the company are more likely to suffer.
If the work does not provide adequate personal satisfaction, or even causes dissatisfaction, this can develop into persistent psychological stress over a longer period of time. The associated lower self-esteem increases the chance of suffering from mild depression or
anxiety. If this condition remains unresolved over an extended period of time, it can lead to emotional exhaustion, which can result in an increase in depression. In studies prior to 1980, the averaged correlation of job satisfaction and depression was <math>r=0.424</math> . This was followed by a slight increase to <math>r=0.446</math>  by 1990, but since 1990 the value has dropped to <math>r=0.316</math>  <ref name="faragher2003"/>. Workers with increased overcommitment have a 1.92-5.92-fold chance of experiencing psychosomatic symptoms such as depression compared to workers with low levels of commitment. The data reported by Van Vegchel et al. reviewed mostly only examined the relationship between Effort- Reward imbalance and overall psychosomatic health. Most of these studies found a positive correlation between ERI and psychosomatic outcomes. Workers who work in a high-effort-low-reward situation have an increased chance of 1.44-18.55% psychosomatic outcomes, such as depression <ref name="vanvegchel2005"/>. An analysis of existing studies conducted by Johannes Siegrist
2006 conducted an analysis of existing studies supports the results collected so far. The combination of high effort and low reward increases the probability of a depressive disorder by 50 to 150%. The results are more consistent for men. Siegrist also confirms Faragher et al.'s hypothesis that the effects are more pronounced in groups with low occupational status <ref name="siegrist2006"/>.

==== Burnout ====

The number of burnout cases has increased by 700 percent in the last 15 years <ref name="stiftung2016"/>). Burnout is expressed as a feeling of exhaustion and lack of energy. The sufferer builds up a mental distance to his work and associates negativity with his workplace. Job efficiency declines rapidly <ref name="dick2010"/>. Faragher et al. found a correlation of <math>r=0.409</math>  between job satisfaction and burnout for this effect of poor effort to reward ratio. This is the highest score of correlation between job satisfaction and consequences found in this study. The correlation was <math>r=0.435</math>  between 1980 and 1989 and <math>r=0.379</math>  from 1990 onwards. Consequently, a decrease in correlation can be observed <ref name="faragher2003"/>. All of the studies conducted by Van Vegchel et al. confirmed that when there is an imbalance of effort and reward there is an increased risk of emotional exhaustion. The influence of overcommitment was examined by some studies, but no significant influence could be confirmed. A study by Bakker et al. only examined the relationship of over-commitment of nurses to the risk of the disease <ref name="Bakker2000"/>. Other studies <ref name="dejonge2001"/> could not confirm this effect. the influence of over-commitment cannot be applied to the population at large (Van Vegchel et al. can be applied to the population <ref name="vanvegchel2005"/>.
The study by Bakker et al. is nevertheless a a good example to understand the influence of an imbalance of effort and reward on a Burnout diagnosis to be understood. The sample consisted of 204 nurses in Germany. Those who experienced an imbalance between effort and reward experienced increased levels of emotional exhaustion. Furthermore, interaction  effects became apparent, indicating that emotional exhaustion combined with decreased personal accomplishment was particularly prevalent among the
nurses who experienced effort-reward imbalance <ref name="Bakker2000"/>.

=== Physical health effects ===

Effort-reward imbalance results in physical problems in addition to the psychological and psychosomatic problems addressed. Physical problems related to the model can be divided into cardiovascular diseases, muscular problems, or the general restriction of the musculoskeletal system. There is a low but present correlation of <math>r=0.113</math> between ERI and cardiovascular diseases and also a low but present correlation of <math>r=0.078</math> between job satisfaction and muscular problems <ref name="faragher2003"/>.

==== Cardiovascular diseases ====

The Effort-Reward-Imbalance model was originally designed to predict and explain the effects of stress at work on the heart and blood vessels <ref name="siegrist2004"/>. An analysis of data from more than 600,000 men and women from 26 studies has confirmed the association between work-related stress and cardiovascular disease, such as stroke. Those who work more than 48 hours a week have a significantly increased risk. The risk of cardiovascular disease is increased by a factor of 1.34 on average for workers who are under stress. Furthermore, work-related stress can lead to a change in lifestyle over time and can lead to obesity. This has an indirect effect on cardiovascular disease <ref name="grossarth-maticek1979"/>. Of the 45 studies reviewed by Van Vegchel et al, 17 examined and confirmed cardiovascular disease symptoms such as hypertension and an increase in cholesterol levels. The risk of diseases is higher by a factor of nine in employees who work with an imbalance of effort and reward <ref name="vanvegchel2005"/>. It was found that the risk for women is increased mainly by over-commitment, and for men by effort-reward imbalance <ref name="peter1999"/>. Since 1989, the correlation between job satisfaction and cardiovascular disease has nearly tripled from <math>r=0.049</math> to <math>r=0.137</math> <ref name="faragher2003"/>. The Whitehall II study by Kuper et al, confirms the above observations. Workers who experienced an imbalance of effort and return had an increased risk of coronary heart disease by a factor of 1.65. The British Whitehall study also found an increased risk of developing type 2 diabetes, another risk factor for cardiovascular disease. However, this fact was only observed in the male participants of the study <ref name="kuper2002"/>. Overall, it can be concluded from this summary of studies that over-commitment and a poor work/outcome ratio can have life-threatening consequences. As a project manager, it's essential to acknowledge this fact and modify your expectations of the project team accordingly.

==== Muscular problems/limitations of the musculoskeletal system ====

Work-related musculoskeletal limitations are a widespread health problem. They account for 61% of all work-related disorders. A 2014 literature review by Koch et al. examined 19 studies on the effects of effort-reward imbalance on the human musculoskeletal system. The influence of the external ERI hypothesis was found to be moderate, as 13 of the 19 studies recognized a significant correlation was recognized. Just 4 studies confirmed the influence of the overcommitment hypothesis on the limitation of the musculoskeletal system. Accordingly, there is no application to the whole population. 5 of the 19 studies examined the interaction hypothesis, of which only one study was able to establish a correlation. Accordingly, only the ERI hypothesis can be classified as significant <ref name="koch2014"/>. A 2014 study of 199 childcare workers in Hamburg, Germany, was able to confirm the association between Effort-Reward Imbalance and physical problems. The risk of suffering muscular problems or experiencing physical stress is increased by a factor of 4 when the effort-reward balance is poor. Especially the lower back and the neck are risk areas of the body <ref name="koch2017"/>. The overall correlation between job satisfaction and physical problems is <math>r=0.287</math>. However, the correlation between job satisfaction and muscular problems is considered low at <math>r=0.078</math> <ref name="faragher2003"/>.

==== Effects on behavior ====

The impact of the model on individual behavior can be reduced to two primary observations. First, studies have found that there is a positive correlation between stress at work and increased smoking. To this end, in a study with study participants from a socioeconomically and occupationally homogeneous group consisting of 163 employees of a large industrial company, the relationship between psychosocial work stress and cigarette smoking was analyzed. The probability of belonging to the group of regular smokers in the presence of a poor work effort-reward ratio is more than four times as high (4.34) as in the absence of this imbalance <ref name="peter1991"/>. Prolonged stress leads to dysfunction of the mesolimbic dopamine system, which stimulates addictive behavior. In another cross-sectional study in the metalworking industry, the relationship between effort-reward imbalance and increased alcohol consumption was confirmed. The desire to relax and switch off from everyday life is also of great relevance, as both points are addressed in the Effort-Reward-Questionnaire <ref name="vanvegchel2005"/>.

==== Further health consequences ====

Another effect of Effort-Reward Imbalance is hypertension. Hypertension leads to an absence of disease, which means that the body works in survival mode in stressful situations, preventing infections. Once this work-related stress situation is overcome, this protective mechanism of the body is abruptly shut down and the retained infections break out in a worse form <ref name="peter1999"/>. Furthermore, in the meta-analysis by Faragher et al. correlations of <math>r=0.429</math> and <math>r=0.420</math> were found for the association of job satisfaction with employee self-esteem and anxiety <ref name="faragher2003"/>.

== Projectmanagement implications ==

Project managers can use the ERI model as a useful guide. The model can help design and manage projects in a way that promotes employee well-being and productivity. 

Possible implications for project managers include: 

*	'''rewards''' As a project manager, ensure that the rewards of the project are clearly defined. Each project member needs to know what they are working towards and what they will receive in return for their efforts and effort in contrast. This includes monetary rewards such as salary and benefits but also intangible rewards such as recognition and opportunities for growth, advancement and development.

*	'''transparency''' Be clearly defined and transparent about the effort of the project being worked on. Project participants must have a clear understanding of the effort and results expected for the project. Realistic goals, milestones, and deadlines must be set and the appropriate resources and support needed to achieve them must be provided. By doing these two things, the effort and reward of the project will be calculable for each project member. 
*	'''workload''' The project manager must ensure that the workload is feasible. Overloading the staff will result in an imbalance of effort and return and may lead to the health consequences described. Accordingly, the workload must be appropriate and distributed among enough project members. It is important to select the right number of project members to make this goal feasible.
*	'''engagement''' As a project manager, it is important to involve and engage the project members in the project. If all members feel that they are responsible for their work and can control it themselves, the personal reward in the form of feelings of happiness when the project is successful is also increased. This leads to a more positive relationship between effort and return. It is important to encourage project members to participate in decision-making and problem-solving processes and to give them the opportunity for feedback and suggestions.
*	'''development''' The project manager should always make the project members feel that they have the opportunity to develop, grow and strengthen their skills through the project. Employees who feel that they are growing in their role are more likely to be satisfied have a better effort to reward ratio. The project manager should also provide training and development opportunities.
*	'''job satisfaction''' In project management, job satisfaction is closely linked to project success as well as factors such as team dynamics, communication and leadership. When team members are satisfied with their work, they are more likely to be motivated and productive. Therefore, project managers must prioritize creating a positive work environment that promotes job satisfaction.
*	'''team cohesion''' The ERI model also suggests that social support and team cohesion can reduce the negative effects of effort-reward imbalance. In project management, team cohesion is critical to success because it fosters communication, collaboration, and a sense of common purpose. Project managers must prioritize building strong relationships among team members and fostering a supportive team culture. Joint activities as a project team can be helpful in increasing the sense of community <ref name="siegrist2016"/> <ref name="Siegrist1996"/> <ref name="siegrist2004"/>


Overall, it is really important that companies and project managers recognize that a balanced relationship between effort and reward has a high significance for the health of the employee but also in the medium and long term on the company. Financial interests should not take precedence over employee health. This requires a reordering of priorities. Of course, profit maximization must continue to be an important goal of a healthy company, but this should not be at the expense of employee health. Companies and project managers should use strategies to manage stress and improve the work climate to ensure a good working environment in the long term. Large companies should be able to offer additional psychological support, especially for employees with diagnosed mental health problems. Furthermore, it should be mentioned that adjusting the selection process for hiring employees can prevent imbalance. The requirements that are placed on the applicant during the hiring process should be clearly defined. There should be no deviation from these clearly defined mental and physical requirements unless necessary. Adjustment to the requirements should still be possible on the part of the employer and the project manager, but only with simultaneous adjustment of the reward to maintain the balance between effort and reward. Maintaining the balance is also of great interest to companies, as it avoids unwanted terminations. 
There are a number of measures that can be taken to ensure that people with mental illness receive early treatment in line with formal treatment guidelines and reduce the risk of relapse. These include factual information for all employees, confidence in action on the part of project managers through training (including role plays on how to talk to an employee who may be suffering from mental health problems), an open and non-stigmatizing corporate culture, and reintegration measures. Costs due to presenteeism and absenteeism can be avoided by creating a faster path to professional treatment. In addition, project managers should always take the initiative whenever possible. The affected employee should be approached if they feel they have become unfit for work. There should be no fear of contact. Concerns about the employee's well-being should be communicated and observations addressed directly. It should be imperative to offer to support the employee in any further steps <ref name="stiftung2016"/>

== References ==
<references>


<ref name="Siegrist1996"> Siegrist, J. (1996). Adverse health effects of high-effort/low-reward conditions. Journal of Occupational Health Psychology, 1(1), 27–41. https://doi.org/10.1037/1076-8998.1.1.27 </ref>

<ref name="Bakker2000"> Bakker, A. B., Killmer, C. H., Siegrist, J. & Schaufeli, W. B. (2000). Effort-reward imbalanceand burnout among nurses. Journal of Advanced Nursing, 31(4), 884–891. https://doi.org/10.1046/j.1365-2648.2000.01361.x </ref>

<ref name="dejonge2001"> de Jonge, J., van Vegchel, N., Meijer, T. & Hamers, J. P. H. (2001). Different effort constructs and effort-reward imbalance: effects on employee well-being in ancillary health care workers. Journal of Advanced Nursing, 34(1), 128–136. https://doi.org/10.1046/j.1365- 2648.2001.3411726.x </ref>

<ref name="hanson2000"> Hanson, E. K. S., Schaufeli, W., Vrijkotte, T., Plomp, N. H. & Godaert, G. L. R. (2000). The validity and reliability of the Dutch Effort–Reward Imbalance Questionnaire. Journal of Occupational Health Psychology, 5(1), 142–155. https://doi.org/10.1037/1076-8998.5.1.142 </ref>

<ref name="honda2017"> Honda, A., Date, Y., Maeta, S. & Honda, S. (2017). IMPACT OF EFFORT-REWARD-IMBALANCE ON PSYCHOLOGICAL DISTRESS IN JAPANESE CARE STAFF. Innovation in Aging, 1(suppl_1), 1107. https://doi.org/10.1093/geroni/igx004.4055 </ref>

<ref name="faragher2003"> Faragher, E. B. (2003). The relationship between job satisfaction and health: a meta- analysis. Occupational and Environmental Medicine, 62(2), 105–112. . </ref>

<ref name="greif1991"> Greif, S., Bamberg, E. & Semmer, N. (1991). Psychischer Stress am Arbeitsplatz. Hogrefe </ref>

<ref name="grossarth-maticek1979"> Grossarth-Maticek, R. & Grüntzig, A. R. (1979). Kognitive Verhaltenstherapie: Rauchen Übergewicht Emotionaler Stress (Delaware Edition) (1. Aufl.). Springer Berlin Heidelberg. </ref>

<ref name="hautzinger2010"> Hautzinger, M. (2010). Akute Depression. Hogrefe Verlag. </ref>

<ref name="niedhammer2000"> Niedhammer, I., Siegrist, J., Landre, M. F., Goldberg, M., & Leclerc, A. (2000). Etude des qualites psychometriques de la version francaise du modele du Desequilibre Efforts/ Recompenses (Psychometric properties of the French version of the Effort–reward Imbalance model). Revue d’epidemiol et de sante publique, 48(5), 419–437. </ref>

<ref name="kauffeld2019"> Kauffeld, S., Ochmann, A. & Hoppe, D. (2019). Arbeit und Gesundheit. Springer-Lehrbuch, 305–358. https://doi.org/10.1007/978-3-662-56013-6_11 </ref>

<ref name="koch2014"> Koch, P., Schablon, A., Latza, U. & Nienhaus, A. (2014). Musculoskeletal pain and effort-reward imbalance- a systematic review. BMC Public Health, 14(1),
https://doi.org/10.1186/1471-2458-14-37 </ref>

<ref name="koch2017"> Koch, P., Kersten, J. F., Stranzinger, J. & Nienhaus, A. (2017). The effect of effort-reward imbalance on the health of childcare workers in Hamburg: a longitudinal study. Journal of Occupational Medicine and Toxicology, 12(1), 1. https://doi.org/10.1186/s12995-017-0163-8 </ref>

<ref name="kuper2002"> Kuper, H. (2002). When reciprocity fails: effort-reward imbalance in relation to coronary heart disease and health functioning within the Whitehall II study. Occupational and Environmental Medicine, 59(11), 777–784. https://doi.org/10.1136/oem.59.11.777 </ref>

<ref name="vanvegchel2005"> van Vegchel, N., de Jonge, J., Bosma, H. & Schaufeli, W. (2005). Reviewing the effort–reward imbalance model: drawing up the balance of 45 empirical studies. Social Science & Medicine, 60(5), 1117–1131. https://doi.org/10.1016/j.socscimed.2004.06.043 </ref>

<ref name="siegrist2004"> Siegrist, J., Starke, D., Chandola, T., Godin, I., Marmot, M., Niedhammer, I., & Peter, R. (2004). The measurement of effort-reward imbalance at work: European comparisons. Social science & medicine, 58(8), 1483-1499. </ref>

<ref name="siegrist2006"> Siegrist, J. & Marmot, M. (2006). Social Inequalities in Health: New Evidence and Policy Implications (1. Aufl.). Oxford University Press. </ref>

<ref name="siegrist2016"> Siegrist, J., & Wahrendorf, M. (2016). Work stress and health in a globalized economy: The model of effort-reward imbalance. Springer. </ref>

<ref name="stiftung2016"> Stiftung Deutsche Depressionshilfe (2016). Zahlen und Fakten über Depression -AOK https://www.aok-bv.de/imperia/md/aokbv/presse/pressemitteilungen/archiv/2018/07_faktenblatt_depressionen.pdf </ref>

<ref name="peter1991"> Peter, R., Siegrist, J., Stork, J., Mann, H. & Labrot, B. (1991). Zigarettenrauchen und psychosoziale Arbeitsbelastungen bei Beschäftigten des mittleren Managements. Sozial- und Präventivmedizin SPM, 36(6), 315–321. https://doi.org/10.1007/bf01368738 </ref>

<ref name="peter1999"> Peter, R., Alfredsson, L., Knutsson, A., Siegrist, J. & Westerholm, P. (1999). Does a stressful psychosocial work environment mediate the effects of shift work on cardiovascular risk factors? Scandinavian Journal of Work, Environment & Health, 25(4), 376–381.https://doi.org/10.5271/sjweh.448 </ref>

<ref name="peter2002"> Peter, R. (2002). Psychosocial work environment and myocardial infarction: improving risk estimation by combining two complementary job stress models in the SHEEP Study. Journal of Epidemiology & Community Health, 56(4), 294–300. https://doi.org/10.1136/jech.56.4.294 </ref>

<ref name="stanhope2017"> Stanhope, J. (2017). Effort–Reward Imbalance Questionnaire. Occupational Medicine, 67(4), 314–315. https://doi.org/10.1093/occmed/kqx023 </ref>

<ref name="statistisches2015"> Statistisches Bundesamt (2015) Gesundheit – Todesursachen in Deutschland Verfügbar unter:https://www.destatis.de/DE/Themen/Gesellschaft-
Umwelt/Gesundheit/Todesursachen/Publikationen/Downloads-Todesursachen/todesursachen-2120400157004.pdf?__blob=publicationFile [01.05.2023] </ref>

<ref name="dick2010"> Dick, T. B. (2020). Burnout, burnout, burnout is burning me out. Journal of the American College of Clinical Pharmacy, 3(3), 567–568. https://doi.org/10.1002/jac5.1207 </ref>