Working Conditions of Occupational Physicians—A Scoping Review

Occupational physicians (OPs) offer a wide range of health support for employees and are confronted with varying job characteristics and demands. They monitor occupational health and safety and promote work(place)-related health measures and assessments. While helping employees to (re)gain a healthy status, their own job satisfaction as well as the investigation of their working conditions have earned limited research attention. Thus, this scoping review aims to summarize the current state of knowledge concerning OPs’ working conditions, i.e., work-related resources and stressors. PubMed, Web of Science and LIVIVO as well as grey literature were screened for relevant English or German articles until 10/2021. From a total of 1683 identified publications, we analyzed 24 full text articles that fulfilled all inclusion criteria. The overall study sample included 3486 male (54.6%), 2892 female (45.3%) and 5 diverse OPs, from which 1049 OPs worked in full-time (85.6%) and 177 in part-time (14.4%). The majority (72.4%) worked for the Occupational Health Service (OHS), 13% were self-employed, and 14.6% worked for a company/in-house service. The classification of stressors and resources was based on an inductively generated categorization scheme. We categorized 8 personal, relational and environmental resources and 10 stress factors. The main resources were support for personnel development and promotion, positive organizational policy, promoting work-life balance and other aspects of health. Key stressors were information deficits, organizational deficiency and uncertainty as well as socioeconomic influences and high professional obligations. The working conditions of OPs are still a topic with too little research attention. This scoping review reveals several starting points to maintain a healthy OP workforce and gives recommendations for action for the near future.


Introduction
Over the past 20 years, there has been an increasing demand for good solutions in occupational health [1]. Corporate and environmental structures have changed due to demographic developments: the workforce is aging and diversifying [2]. Along with the changing workplace conditions of employees (stronger shift towards workplace health promotion, demographic change and increase of mental illnesses), new challenges for OPs of the 21st century arise. A major challenge for occupational health services is the need for the development of structures and ways of working that maintain (1) integrity in a more commercialized environment and (2) both the quality of service and the attractiveness of the profession in the long term [3]. Higher general health status of employees is a major asset for companies to yield better productivity and competitiveness. "Occupational safety and health includes all measures which ensure and improve work safety and health protection. Operational management of occupational safety and health is responsible for identifying needs, making decisions and eventually taking measures" [4]. In general, occupational physicians (OPs) may play a crucial role for the prevention and rehabilitation of employees. Through workplace inspections and consultations with employees, most OPs have a thorough knowledge of working conditions and often a direct access to change specific work demands. However, this constellation often creates a perceived tension in the triangle employee-employer-physician with un-communicated reservations regarding the representation of interests.
Even though OPs in Germany make up a rather small proportion of all working physicians in Germany [5], their far-reaching involvement on a personal, organizational, but also political level is nevertheless evident. In Germany, the general conditions of OP service are ruled in the "Act on Occupational Physicians, Safety Engineers and Other Occupational Safety Specialists" [6]. The type of employment of an OP depends fundamentally on the respective circumstances of the company [7]. In principle, there are several employment relationships: (full or part-time) salaried OPs, freelance OPs and physicians that work for an intercompany occupational health service. A full-time OP is usually found in large companies or in companies with high-risk potentials (e.g., in a chemical plant or in the Armed Forces) to find specific measures for their requirements. Outsourced solutions use freelance OPs, often in small and medium-sized enterprises (SMEs). Working for the inter-company occupational health service, an OP may also join a registered association or an independent service company that provides the medical care.
Despite their important role as investigators of work-related risk factors and as a creator of healthy working conditions, OPs are also active employees themselves, thus, equally exposed to potential work-related risk and occupational hazards. The research indicated that agency and well-being, as well as health status, play a crucial role in the experienced quality of and satisfaction with work. Health workers are often exposed to special stresses and complain about a high burden of inadequate work conditions. They are particularly frequently affected by absenteeism due to mental disorders [8]. Their mental health and wellbeing should be of special interest not only regarding their personal health, but also as their mental health and wellbeing affects the quality of care [9,10]. Especially during the global pandemic caused by the coronavirus disease, healthcare workers were confronted with great psychological distress [11][12][13][14].
The World Health Organization (WHO) defines health as " a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity" [15]. Job demands that can affect employees' mental health are, for example, leadership, organizational justice, effort-reward imbalance, atypical forms of employment, social support or job insecurity [16]. In healthcare workers, job satisfaction and subjective wellbeing is associated with workplace performance, retention, instability of available workforce and shortage of healthcare workers [17]. Moreover, heavy workloads, long shifts, a high pace, lack of physical or psychosocial safety, chronicity of care, moral conflicts, job (in)security, social support and bullying can result in psychological distress, leading to burnout, depression, anxiety disorders or sleeping disorders [10,[18][19][20][21].
The idea of working conditions impacting employees' health is not new. Two still widely used models that provide a theoretical background, are the transactional stress model and the job demand control (JDC) model. Using job satisfaction and the concept of well-being are more recent approaches in investigating work conditions.

Transactional Stress Model
To explore the OPs' working conditions, we use the indicators "stressors" and "resources". According to the transactional stress model of Lazarus and Launier [22] (1981), stress mainly depends on the cognitive evaluation and coping strategies that the individual may apply to process environmental stimuli. According to their model, stressors are not only reduced to external stimuli, but take also individual intrinsic factors into account. The three essential stress-relevant relationships are: harm/loss, threat and challenge. The choice of the coping strategies belongs to the most important aspect in the individual handling of stress and has a significantly greater influence on health or illness than the actual stress episodes. There are two main categories to cope with the stressors: (a) change of the stressed transaction (instrumental) and (b) the regulation of emotion (palliation). The instrumental coping has a direct influence on the stressful situation. Under the use of acquired skills and information, the problem is solved or the obstacle removed. Palliative coping, on the other hand, aims at regulative emotions such as relaxation. In the best case, negative emotions such as fear or anger should be controlled and diminished.
The selection of coping strategies described above depends on a variety of circumstances: situational context or the environment determines which form of coping is appropriate and at the same time most promising. The degree of (perceived) helplessness can also be a factor influencing the choice of coping strategies. Furthermore, Bamberg et al. [23] (2003) have demonstrated with their model that the development of stress is not merely attributable to the individual person-and condition-related factors, but is rather based on their mutual interaction.

Job Demand Control (JDC) Model
Another widely used model is the Job Demand Control (JDC) model by Karasek and Theorell [24] (1990). He conceptualized mental stress as a result from the amount and intensity of job demands and the amount (time and intensity) of work, as well as from the freedom of action and decision (latitude) of the respective employee. Karasek and Theorell understand the combination of work requirements and decision latitude as a two-dimensional model from which four different types of psychosocial perception of an occupation can result: high-strain jobs, active jobs, low-strain jobs and passive jobs. The four dimensions of the model vary between different types of psychosocial stress depending on the extent of potential work intensity and the potential scope for action. In addition, a third dimension was added to the JDC model at the end of the 1980s: the influence of social support. Karasek and Theorell predict a combination of low social support, low decision-making latitude and high decision-making potential, a low degree of decision-making freedom and, at the same time, high work demands and a high stress level for employees [24]. One of the most important conclusions of the JDC model, according to Karasek, is the possibility to improve the work-related mental health of employees without affecting the productivity of the organization: It appears that the stress of the workplace can be reduced by increasing decision-making latitude, irrespective or independent of changes in job demands. The key point lies, accordingly, in the employee's ability to make important decisions about his or her work.

Job Satisfaction
A significant model in understanding work conditions is the concept of job satisfaction, which has been linked to both organizational behavior and physical and mental health [25]. Due to the shortage of nurses, this concept has been widely used to investigate how the nursing workforce can be stabilized. The main attributes job satisfaction gained via concept analyses show that "fulfillment of desired needs within the work setting", "happiness or gratifying emotional responses towards working conditions" and "job value or equity" are key features impacting the overall job satisfaction. These attributes interplay with demographic, structural work characteristics and environmental variables [25].

Concept of Psychological Well-Being
Another widely used and early concept to understand work condition is the concept of psychological well-being [26,27]. Previous work has investigated its influence on vocational identity and career commitments [28,29]. Higher socioeconomic status contributes to better health and well-being and different types of work may also predict the perceived level of well-being, with work and educational experiences being the strongest predictors of wellbeings, especially among older adults [30]. Linking psychological well-being to physical health, biological regulation and neuroscience delivers additional objective indicators for more general benefits [31]. Tools to assess psychological well-being have now been incorporated into many fields in order to describe challenges and transition periods such as adolescence or new job opportunities.
Staying healthy at work is highly relevant. OPs are assigned with a large number of specific tasks (e.g., including numerous legal foundations/basis, diverse employment relationships, working hours). The aim of the current scoping review is to assess the current knowledge concerning OPs' working conditions. Which specific work-related resources and stressors have been reported? The presented resource and stress models are applied to analyze the extracted working conditions.

Materials and Methods
This scoping review was conducted by a multidisciplinary team with proven experience in health services research, psychology and rehabilitation science. The review process comprised (a) the identification of the research question, (b) identification of relevant studies, (c) study selection, (d) data extraction (mapping) and (e) data syntheses and reporting of results. We herein followed established reporting guidelines for scoping reviews (PRISMA P; PRISMA ScR) [32,33].

Identification of Research Question
We address the following research questions: What are the reported working conditions for OPs, described in international publications over the last 20 years?
To what extent are work conditions described as stressors or resources in this context?

Identifying Relevant Studies, Inclusion and Exclusion Criteria
To identify relevant studies, we will follow the Population-Concept-Context (PCC) framework (see Table 1), recommend by the Joanna Briggs Institute [34] (JBI Manual for Evidence Synthesis, JBI, 2020). This review includes all types of experimental studies, observational/quasi-experimental studies, cross-sectional studies, case studies, and all types of (systematic) reviews published in German or English until the end of 10/2021. There were no restrictions concerning country or region of the world. Additionally, grey literature was hand-searched. Opinion papers, editorials and commentaries were excluded.
Since the initial search showed only a limited number of references, we decided to widen the inclusion criteria as much as possible with respect to the PCC criteria. Articles that were excluded from this study mainly focused on employee health and health professions other than OPs (e.g., general practitioners or nurses) only. Findings that provided separate information on OPs' work conditions were still included. All articles meeting the defined criteria of the PCC framework (see Table 1) were included.

Study Selection
Included databases were Medline (PubMed), Web of Science and LIVIVO. The search strategy contained keywords and subject headings from the PCC framework. According to the JBI approach, the search strategy followed a three-step selection. An initial, limited search in set databases was conducted with following predefined keywords and index terms. The search algorithms were: #1Population: (Betriebsärzt* OR Betriebsarzt OR Arbeitsmediziner* OR "company doctor" OR "company physician*" OR "industrial physician*" OR "company medical officer*" OR Werksarzt OR Werksärzt* OR "work* doctor*" OR "occupational health physician*" OR "occupational physician*") #2Outcome: (Belastungsfaktor* OR Belastung* OR Arbeitsanforderung* OR Arbeitsintensität OR Handlungsspielraum OR Tätigkeitsspielraum OR "decision latitude" OR "job demand*" OR "work demand*" OR demand* OR burden OR resource* OR "soziale Unterstützung" OR "social support" OR Beanspruchung* OR stressor* OR Stressfaktor* OR "load factor*" OR "stress factor*" OR "job related resource*" OR "work related resource*" OR workload OR "job control" OR "job stress" OR "work stress" OR Arbeitsbedingung* OR "working condition*" OR Arbeitssituation OR "work situation") Consecutively, both algorithms were combined by the Boolean operator "AND". Retrieved articles were screened for additional keywords and index terms. A second search including all identified keywords and index terms followed, but yielded no additional results. Following a snowball principle, reference lists of included studies were screened for additional sources. Retrieved articles were imported to Endnote X9 and exported to Rayyan (Cambridge, USA) for the title and abstract screening. First, three reviewers (E.E., L.L. and K.-E.C.) independently conducted a title and abstract screening. Disagreements were reflected and discussed in the team and solved by consensus. The full text screening followed the principles of title and abstract screening. Figure 1 illustrates the full study selection process.

Data Extraction (Mapping)
We used a data extraction chart in Microsoft Excel tailored to the objectives of this review (see Table 2). The chart was piloted by E.E. and adjusted by E.E., L.L. and K.-E.C. in an iterative process. Relevant data of each article were independently extracted by at least two researchers (E.E., L.L. and K.-E.C.). Results were discussed and harmonized in the overall team (E.E., L.L., K.-E.C. and P.K.) led by P.K.

Data Extraction (Mapping)
We used a data extraction chart in Microsoft Excel tailored to the objectives of this review (see Table 2). The chart was piloted by E.E. and adjusted by E.E., L.L. and K.-E.C. in an iterative process. Relevant data of each article were independently extracted by at least two researchers (E.E., L.L. and K.-E.C.). Results were discussed and harmonized in the overall team (E.E., L.L., K.-E.C. and P.K.) led by P.K.

Data Synthesis and Reporting
For data synthesis and reporting we used an inductively generated categorization scheme for resource and stress factors that was piloted by E.E. and adjusted by all study team members in an iterative process. E.E. synthesized and reported all relevant data (top category, description/definition, attribution and total N-assigned studies in absolute frequency) of each article. Subsequently, all results were cross-checked with P.K. for comprehensibility and consistency.

Results
The surveyed studies included a total of 3486 male (54.6%), 2892 female (45.3%) and 5 diverse OPs, from which 1049 OPs worked in full-time (85.6%) and 177 in part-time (14.4%). The majority (72.4%) worked for the OHS, 13% were self-employed and 14.6% worked for a company/in-house service. The average age was high (1.1% younger than 36 years, 4.7% being between 36 and 45 years old, 78.9% aged 45 to 55 years and 15.6% aged over 55 years). Table 3 summarizes the most important extraction results of the review. Further information and the entire table of extraction results can be found in the appendix (Tables A1 and A2). The presentation of results follows the alphabetical order of the first author's last name. With the exception of some Japanese, Turkish and international studies, most of the found evidence were reported by European groups.     A total of 108 accompanied consultations matched to 103 non-accompanied consultations; ill health retirement; diagnosis; complexity; time (duration); consultation process indicators; the consultations occurred in clinics held in a number of different locations and included referrals from the public and private sectors and from a variety of workplaces. Public sector referrals were predominantly from two large local authorities (a) Accompanied consultations more likely to be connected with: ill health retirement (p < 0.01); neurological diagnosis or multiple diagnosis (p < 0.01); rated as complex (p < 0.01); taking longer than 30 min (p < 0.01); (b) 54% of companions were spouse/partner (of patient); (c) an impact by the companion was recorded in 81% of consultations; (d) in 36% of consultations the impact of the companion was helpful or in agreement with the advice provided by the OPs; (e) in 28% of accompanied consultations interruptions were recorded; (f) 6% of consultation: consultation or companion was difficult; (g) 10 accompanied consultations where companion was a trade union representative was male: 80% (p < 0.05); but only 12% of consultations were rated as complex; half of the consultations: trade union representative provides information; in 30% of consultations: interruptions and asked questions Hoedeman et al. [43]   Maslach burnout inventory (emotional exhaustion, depersonalization, feelings of low personal accomplishment); perceived stress scale (stress level); primary appraisal of identity scale (identity threat; job characteristics (a) 11.8% burnout compared to 5% in French general practitioners (main characteristic of the burnout pattern: feelings of very low personal accomplishment: 63.9%); (b) weak correlations with job characteristics; (c) stress and identity threat correlating with all three dimensions of burnout; (d) perceived stress-> main risk factor for emotional exhaustion and identity threat for feelings of low personal accomplishment Work situation of OPs regarding handling of sickness Certification compared with other physicians, in particular general practitioners (GPs); associations between OPs' experiences of assessing and providing a long-term prognosis of patients' work capacity and some potentially interrelated factors; 163 questions about physician's work with sickness certification mailed to home address; 11 items on sickness certification and general work (a) 46% of OPs had a well-established workplace policy and substantial support from their immediate manager regarding sickness certification tasks, compared with GPs (32%) and especially with physicians working in other clinical settings (14%); (b) collaborations with other team members, with the Social Insurance Agency, and, most of all, with employers, was much more frequent among OPs than among GPs and among the other physicians (employers: 76%); (c) 43% of OPs finding it problematic to handle sickness certification at least once a week (GP: 54%); (d) participation in coordination meetings concerning specific patients on a weekly basis was negatively associated with finding it 'not at all/somewhat problematic' to provide a long-term prognosis about patients' work capacity; (e) OPs seem to have a more favorable work situation in their work with sickness certification; (f) experience of sickness certification consultations as problematic once a month or less often, not experiencing sickness certification tasks as a work environment problem, holding a specialty in occupational medicine, and having a well-established workplace policy regarding sickness certification matters were significantly positively associated with finding assessment of work capacity as 'not at all/somewhat problematic'; (g) participation at least once a week in coordination meetings with the Social Insurance Agency and/or employer regarding sickness certified patients was negatively associated with finding assessing patients' work capacity as 'not at all/somewhat problematic' Moriguchi et al. [49] (2013) Japan n = 557 OPs; Kyoto occupational health promotion center; (response rate: 31% (175 OPs); n = 76 no longer active as OPs; n = 86 OPs who were either; private clinic-based or hospital-based questionnaires via mail in 2008 Examine activities of private clinical-or hospital-based OPs; identify difficulties encountered in occupational health service (a) OPs wished to allocate more time for: examination follow-up (2.6 h/month); mental health care (2.0 h/month); prevention of overwork (1.9 h/month); attendance at the safety and health committee meetings in the plant (1.9 h/month); (b) discrepancy between the current and the desired allocation was greatest for: risk assessment (171% as the desired/current ratio); maintenance and management of work and the work environment (150 and 152%); time allocation for health examinations appeared to be sufficient; (c) major difficulties in: management of mental ill health (36 OPs); guidance of workers on sick leaves (11 OPs); followed by prevention of health hazard due to overwork (30 OPs); diagnosis of return to work (15 OPs); (d) OPs had difficulty in dealing with: industrial hygiene-related issues such as risk assessment (14 OPs) and maintenance and management of work and work environment (11 cases each; (e) respondents were generally self-confident regarding: physical health management (typically providing general health examinations); to solve the problems related to lack of experience with mental health issues referral to experts  (a) Self-employed OPs show the highest job satisfaction on average; they are particularly satisfied with: financial compensation, personal responsibility and job security; (b) OPs of the occupational health service show on average the highest job dissatisfaction; they are particularly dissatisfied with the recognition of their work; (c) OPs employed in the company show medium satisfaction in almost all points (d) highest dissatisfaction of all groups concerns work pressure; (e) further dissatisfaction factor mentioned: poor image of the profession; (f) commercialization of the profession as a negative influence on being able to perform work in compliance with professional standards; (g) biographical variables (such as age or gender) without any influence on the job (dis-)satisfaction of OPs; (h) strongest influence on overall job satisfaction: level of autonomy and intrinsic/social aspects; (i) highest negative impact on job satisfaction: lack of professional challenges, high administrative burden and poor public image of the profession In general: (a) the majority of surveyed OPs see prevention of occupational cancers as part of their role (n = 15); (b) full-time OPs report less autonomy to act (n = 5); (c) a minority of OPs (n = 5) appear to prefer prevention that goes beyond the legal framework; (d) due to lack of time and resources: less time for occupational health activities per company than is actually required by law (n = 7); (e) low participation of workers in the prevention of occupational cancers (n = 15) for those working at the occupational health service: (a) lack of independence (n = 8); (b) little room for maneuver/ little scope for action (n = 10); (c) dependence on the employer; danger of own professional existence Zaman et al. [57] (2017) The Netherlands n = 13 OPs (unknown response rate) and n = 8 cancer patients (unknown response rate) Qualitative study with a cross-sectional descriptive design To evaluate the feasibility of OPs trained in oncological work-related problems, and in providing work-related support to cancer patients within the curative setting (semi-structured interview with predefined topic list) (a) The most frequently mentioned facilitator was 'being more independent than an OP in the company'; (b) positive feedback from health care providers and patients about the received care and support that the OPs had given, and the additional knowledge of the OPs about cancer and work-related problems; (c) working within the clinical setting or outpatient clinic gives the opportunities to cooperate with other health care disciplines; (d) major barriers: lack of financial support for the OPs, unfamiliarity of patients and health care providers with the specialized OP; (e) OPs are not structurally embedded in the health care system; (f) non-optimal timing/scheduling of the consultations Table 4 displays identified resources of the OPs. We categorized eight resources, some of which also loaded negatively as stressors: social interaction, perceived repuation of the profession, characteristics of the emploment relationship and scope for decisionmaking/action (see Table 5). Other factors were only identified to be loaded positively, including aspects of health, work-life balance, opportunities for personnel development and promotion, as well as organizational policy.    Table 5 displays identified stress factors of the OPs. Socioeconomic factors, perspectives, information deficits, organizational complication, uncertainty factors and professional obligations were identified as stressors that had no positive loadings.

Discussion
Given the declining number of employed OPs, there is a need to focus on eliminating stress factors and emphasizing resources in order to increase the overall attractiveness of the occupation. We identified 8 resources and 10 stressors (personal, relational and environmental factors) for OPs. Of those, some factors loaded both positively as well as negatively (i.e., social interaction, reputation of the profession, characteristics of the employment relationship and scope for decision-making/action). Support for personnel development and promotion, positive organizational policy, promoting work-life balance and other aspects of health were the main resources. Information deficits, organizational deficiency and uncertainty were key stressors besides socioeconomic influences and high professional obligations.
The majority of the surveyed OPs worked for the OHS (72.4%). Earlier studies have found that the type of employment may cause very different working conditions for OPs (e.g., [39,58]). A direct comparison of the employment relationships shows that selfemployment and/or part-time work represents a resource for OPs, whereas employment with the occupational health service and/or full-time work can be classified as a stress factor. One reason for this could be that full-time employment in the company is only an option for an OP, when the number of hours worked exceeds 1640 per year, and the hurdles for a freelance existence are too great. Freelance work is often associated with less social interaction and peer feedback. Of course, the employment relationships and the functions of the individual OPs may vary in their characteristics from country to country.
The majority of the OPs was over 45 years old (95.5%), with one in seven being over 55 years. This fits with the observation that the next generation of OPs is lacking in occupational medicine. Accordingly, the stress factors of occupational medical practice should be critically scrutinized and remedied as best as possible. Above all, the organizational difficulties, and the prejudiced assessment of the occupational profile by external parties can be counteracted with educational work.
An essential influence for the appraisal of stress or resource was the amount of decisionlatitude and agency. This is because it is evident, also according to the JDC model, that the highest levels of satisfaction are found in active jobs where there are high job demands but also opportunities for the use of authoritarian actions and decisions. The Federal Institute for Occupational Safety and Health (German: Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, BAuA) sees great potential for action in education and training. In particular, the steady shift from pure occupational health and safety measures toward workplace health promotion is leading to numerous new fields of application that place the occupational health professional in the foreground as a central actor [59]. Compared with other specialties, there are also many structural advantages for OPs. For example, most OPs do not have to work nights, shifts or on weekends. Their average hours worked per week are lower than those of hospital doctors [37], who work up to 59 h per week, which may in turn endanger their own health. More attention should be paid to the field of occupational medicine already in medical school: Continuing education should be subsidized and the advantages of the profession over other, clinical health professions should be discussed.
The working conditions of OPs are still a topic with too little research attention. One possible reason may be that OPs account for only 3.3 percent of all working physicians in Germany (in comparison, hospital physicians, for example, account for more than 50 percent) and thus do not justify a sufficient need for research [60]. Since OPs take a fundamental role in the diagnostics and management of employee health, a closer look at work-related stress factors as well as the resources of OPs is essential, as both occupational health systems as well as companies and their employees can benefit from healthy and satisfied OPs [47].
Psychological well-being as well as job satisfaction are widely used to identify work conditions as work-related stressors and resources [16]. Therefore, both may be key concepts to elucidate work-related stressors and resources for OPs. Since OPs work in multidisciplinary teams and are perceived as situated in a triangle between patient-employer-physician, further research would be necessary to illuminate the resulting specific demands and resources. Only if we ensure that the working conditions for OPs are appropriate, we can assume that they are also able to contribute to an adequate occupational health service, not at least in the sense of organizational health literacy.

Strengths and Limitations
To our knowledge, this scoping review is the first systematic and standardized overview of the working conditions of OPs. Our recommendations may be perceived to be not yet specific enough. Evidence-based recommendations for practice need a sufficient level of scientific knowledge. Considering our broad approach, the total amount of findings was very limited. The above-mentioned aspects demonstrate that there is a clear need for research (including prospective trials), which must be implemented in the future.
One possible limitation of our scoping review is that it mainly covers European and some Asian studies. Occupational health solutions vary across countries, of course. It would have been interesting to include more (national) grey literature such as guidelines, website information of associations and company in-house information. Moreover, language restriction may have biased our results.

Conclusions
The nature and characteristics of OPs' work significantly differs from that of other medical professions due to numerous framework conditions. This scoping review delivers concrete indications for science and practice to counteract potential stress factors and strengthen resources perceived by OPs. Regarding the targeted survey of the working conditions of OPs, there is a need for a larger number of more objective procedures that are not exclusively based on a questionnaire-based, subjective self-assessment.
Only with an occupational health promotion with targeted support of Ops can the next generation of OPs can be secured. "Individual physicians will benefit, the organizations employing those physicians will benefit, and so too will the occupational health systems and the workers" [47].
Inspired by on our findings, we would like to propose the following recommendations for action for the near future: 1. Drive research forward (both people-and practice-oriented); 2. Secure the next generation (greater expansion and emphasis on occupational medicine in medical studies); 3. Eliminate information deficits (promote continuing education in occupational medicine); 4. Optimize interdisciplinary teamwork (e.g., with occupational safety specialists or family physicians); 5. Eliminate prejudices (education/public relations work); 6. Make capital available (discourse on a national, political level); 7. Emphasize the resources of OP activities give greater priority to the issue of prevention in the company.  Institutional Review Board Statement: Not applicable.

Informed Consent Statement: Not applicable.
Data Availability Statement: The datasets used and/or analyzed during the current study are available from the study group on reasonable request. Please contact the corresponding author.

Conflicts of Interest:
The authors declare no conflict of interest. Appendix A Table A1. List of included studies and data extraction. Table A1 includes "Reference", "Sample", "Sociodemographic Data", Research Design" and "Level Of Evidence".     Table A2. List of included studies and data extraction. Table A2 includes "Reference", "Outcome (Objectives/Aim)", "Results", "Indentified Loading Factors/Stress Factors, "Identified Resources" and "Strengths and Weaknesses of Study".

Reference, Country of Origin Outcome (Objectives/Aim) Results Identified Loading Factors/Stress Factors Identified Resources Strengths and Weaknesses of Study
Alaguney et al. [36] (2020) Turkey    A total of 2 authors screened the abstracts of the studies + independently assessed: the risk of bias of the included studies Primary outcome measures: health care (provider)-related; patient-related secondary outcomes (patient-related): sick leave and return to work; functional status (SF-36); depression and anxiety (e.g., interview, Beck depression inventory) Objectives to assess the effectiveness of consultation letters (CLs) to assist primary care physicians or occupational health physicians (OPs) in the treatment of patients with MUPS and diagnostic subgroups None of the studies were performed in an occupational health setting and there were no data on sub-populations of employees, so no conclusions can be drawn on the effect of the intervention for employees regarding return to work or functioning at work; the results show an effect on improving physical functioning and a small effect on reducing social function, which can be of importance in the functioning and return to work of employees, but no conclusions can be drawn with regard to the exact effects Analysis of Consultation Letters (CL): (a) n = 4 studies (267 patients), intervention (CL following a consultation between patient and psychiatrist) resulted in: reduced medical costs (2 studies pooled for outcome (MD = −352.55 US$); improved physical functioning (3 studies pooled for outcome (MD = 5.71); (b) n = 2 (82 patients), intervention (CL following a joint consultation between patient and psychiatrist and physician) resulted in: reduced severity of somatization symptoms, reduced medical consumption, improved social functioning; (c) serious limitations in generalizability of the results to modern health care: most trials reported doctor-related outcomes with patient-related outcomes varying in results; the intervention appears to be far more effective for the most serious but rare disorders, and less so in the more common forms of MUPS; five of the six studies were performed in the United States and four studies before 1995; the studied populations were small and five of the six studies were of moderate quality Conclusion (authors): very limited evidence that a joint consultation with the patient by a psychiatrist in the presence of the physician, together with the provision of a CL, reduces severity of somatization symptoms and medical consumption; final conclusion: CL may be helpful for physicians who treat patients with MUPS (based on the provider-related outcomes). However, until further studies are conducted to find out if the intervention results in improved patient-related outcomes, the overall effectiveness of CLs cannot be demonstrated Koike et al. [45] (2019) Japan Retention rate/trends of OPs and factors associated with it (semiannual survey dates through censuses of physicians from 2002 to 2014) (a) Retention rate from 2012 to 2014: 76% (24% of OPs stopped working full-time); (b) the chance to continue working as an OP decreases when working in a small town or village (p < 0.05); (c) the chance to continue working as a OP decreases if the OP has been working for more than 41 years (p < 0.05); (d) the chance to continue working as an OP increases if an OP has already been registered as an OP in > 2 consecutive survey periods (p < 0.  Maslach burnout inventory (emotional exhaustion, depersonalization, feelings of low personal accomplishment); perceived stress scale (stress level); primary appraisal of identity scale (identity threat; job characteristics (a) 11.8% burnout compared to 5% in French general practitioners (main characteristic of the burnout pattern: feelings of very low personal accomplishment: 63.9%); (b) weak correlations with job characteristics; (c) stress and identity threat correlating with all three dimensions of burnout; (d) perceived stress-> main risk factor for emotional exhaustion and identity threat for feelings of low personal accomplishment (1) increased numbers of workers to follow prevent OPs from performing all their tasks properly (feeling of unfinished work); (2) estimated prevalence of burnout and high rate of people at high risk of low personal accomplishment (higher than in most of the studies that have investigated other specialist groups) Weaknesses: underrepresentation of OPs aged over 60 years; low response rates Ljungquist et al. [48] (2015) Sweden Work situation of occupational health physicians (OPs) regarding handling of sickness certification compared with other physicians, in particular general practitioners (GPs); associations between OPs' experiences of assessing and providing a long-term prognosis of patients' work capacity and some potentially interrelated factors; 163 questions about physician's work with sickness certification mailed to home address; 11 items on sickness certification and general work (a) Among OPs, a rather high proportion (46%) had a well-established workplace policy and substantial support from their immediate manager regarding sickness certification tasks, compared with GPs (32%) and especially with physicians working in other clinical settings (14%); (b) collaborations with other team members, with the Social Insurance Agency, and, most of all, with employers, was much more frequent among OPs than among GPs and among the other physicians (employers: 76%); (c) 43% of OPs found it problematic to handle sickness certification at least once a week (GP: 54%); (d) participation in coordination meetings with the SIO and/or employers concerning specific patients on a weekly basis was negatively associated with finding it 'not at all/somewhat problematic' to provide a long-term prognosis about patients' work capacity; (e) OPs seem to have a more favorable work situation in their work with sickness certification; (f) experience of sickness certification consultations as problematic once a month or less often, not experiencing sickness certification tasks as a work environment problem, holding a specialty in occupational medicine, and having a well-established workplace policy regarding sickness certification matters were significantly positively associated with finding assessment of work capacity as 'not at all/somewhat problematic'; (g) participation at least once a week in coordination meetings with the Social Insurance Agency and/or employer regarding sickness certified patients was negatively associated with finding assessing patients' work capacity as 'not at all/somewhat problematic' month); attendance at the safety and health committee meetings in the plant (1.9 h/month); (b) discrepancy between the current and the desired allocation was greatest for: risk assessment (171% as the desired/current ratio); maintenance and management of work and the work environment (150 and 152%); time allocation for health examinations appeared to be sufficient; (c) difficulties were experienced most often in: management of mental ill health (36 OPs); guidance of workers on sick leaves (11 OPs); followed by prevention of health hazard due to overwork (30 OPs); diagnosis of return to work (15 OPs); (d) many OPs had difficulty in dealing with: industrial hygiene-related issues such as risk assessment (14 OPs) and maintenance and management of work and work environment (11 cases each; (e) respondents were generally self-confident regarding: physical health management (typically providing general health examinations) except for a few specific health examination issues; to solve the problems related to lack of experience with mental health issues, proposals were made such as providing opportunity for exchange of information on these issues with experts for common sharing of experiences and for construction of a network (1) Difficulty in dealing with industrial hygiene-related issues such as risk assessment, and maintenance, and management of work and work environment; (2) difficulties were experienced most often in management of mental ill health and guidance of workers on sick leaves; (3) followed by prevention of health hazard due to overwork; (4) diagnosis of return to work (1) Generally self-confident regarding physical health management (typically providing general health examinations);   To determine and evaluate professional activity (and the related skills and competencies) and the information demands and/or education and training needs of OPs; (self-administered questionnaire with 3 different sections; total of 35 questions: 1. Personal and professional Information; 2. training and updating need (scale variable from 1 = very unimportant to 5 = very important); 3. professional activity and practice characteristics) (a) The Italian continuing medical education (CME) program is not considered to be sufficiently adequate to ensure effective updating of OPs; significant improvement could be achieved by training events discussing topics and issues that really met the practical needs of OPs (4.56) or reducing the costs (4.42) or the distance (< 100 km) of training events (4.28) (scale mean); higher training offer regarding the manual handling of loads (MHL) (15.1%), chemical substances (13.6%), upper limb biomechanical overload (12.2%), carcinogens (11.8%) and work-related stress (9.0%); (b) need to achieve a better cooperation between general practitioners and OPs or other professions ); (f) commercialization of the profession as a negative influence on being able to perform work in compliance with professional standards; (g) biographical variables (such as age or gender) have no influence on the job satisfaction or dissatisfaction of OPs; (h) the strongest influence on overall job satisfaction is the level of autonomy and intrinsic/social aspects; (i) highest negative impact on job satisfaction by: lack of professional challenges, high administrative burden and poor public image of the profession (1) Type of employment: working for the occupational health service; (2) work pressure; (3) lack of social recognition; (4) commercialization of the profession; (5) high administrative burden; (6) lack of professional challenges (1) Type of employment: self-employment; (2) financial remuneration/salary job security personal responsibility/ autonomy Table A2. Cont.

Reference, Country of Origin Outcome (Objectives/Aim) Results Identified Loading Factors/Stress Factors Identified Resources Strengths and Weaknesses of Study
Rodriguez-Jareno et al. [55] (2017) Spain To analyze the medical practice of workers' health examinations in Catalonia (Spain) in terms of its occupational preventive aim (self-developed online survey: Likert-type scales with 4 or 5 categories, numeric text boxes for continuous variables and open boxes for comments were used for the answers) (a) Health professionals from the external OHS dedicated more time, did 2.5 times more health examinations and had nearly 3 times more workers assigned to them (3709 workers/full-time physician vs. 1353 for those in internal services); (b) less than half of participants had adequate and sufficient administrative support; (c) accessibility of workers to the external OHS was low, with 26% of employees making consultations outside health examinations for health problems possibly related to work, compared to 90% in internal services; (d) if additional tests/investigations specific to occupational hazards (laboratory tests or others), not routinely included in the usual health examinations, had to be requested, physicians in external services had significantly more difficulty obtaining them due to administrative/bureaucratic and/or commercial/financial reasons; (e) regarding awareness of sickness absence data, 6% of physicians from the external OHS had knowledge of work-related absences, and 3% had knowledge of non-work-related absences, compared to 75% and 49%, respectively, from internal services; (f) physicians made recommendations to the companies following health examinations but they were reportedly taken into account by companies in fewer than 2/3 of the cases (1) External service; (2) lack of adequate and sufficient administrative support; (3) companies do not accept recommendations of OHPs Internal service Weaknesses: only one survey time; no control/reference group; no causal conclusions possible: potential bias due to self-reporting; selection bias: physicians who did not participate in this study may have been different from that of the respondents weaknesses: no comparison was possible between participating and non-participating physicians who performed health examinations in their usual practice Verger et al. [56] (2010) France Knowledge, attitudes and practices of occupational physicians towards occupational cancers and perceived barriers to prevention (individual interviews using semi-structured interview guides, qualitative content analysis) In general: (a) the majority of surveyed occupational physicians see prevention of occupational cancers as part of their role (n = 15); (b) full-time occupational physicians report less autonomy to act (n = 5); (c) a minority of OPs (n = 5) appear to prefer prevention that goes beyond the legal framework; (d) due to lack of time and resources: less time for occupational health activities per company than is actually required by law (n = 7); (e) low participation of workers in the prevention of occupational cancers (n = 15) for those working at the occupational health service: (a) lack of independence (n = 8); (b) little room for maneuver/ little scope for action (n = 10); (c) dependence on the employer; danger of own existence (professional) (1) Type of employment: primary occupation (full-time) and working for the occupational health service; (2) lack of time and resources; (3) subordination to the employer; (4) ethical issues; (5) low involvement of employees in prevention tasks; (6) little room for maneuver/scope for action, low autonomy of action strengths: sample intentionally diverse; social desirability bias; socio-cognitive bias (esp. in France); small sample size Zaman et al. [57] (2017) The Netherlands To evaluate the feasibility of OPs who is trained in oncological work-related problems, and in providing work-related support to cancer patients within the curative setting (semi-structured interview with predefined topic list) (a) The most frequently mentioned facilitator was 'being more independent than an occupational physician in the company'; (b) positive feedback from health care providers and patients about the received care and support that the OPs had given, and the additional knowledge of the OPs about cancer and work-related problems; (c) working within the clinical setting or outpatient clinic gives the opportunities to cooperate with other health care disciplines; (d) major barriers for being active as an OP were lack of financial support for the OPs and the unfamiliarity of patients and health care providers with the specialized occupational physician; (e) OPs is not structurally embedded in the health care system; (f) timing of the consultation is not yet optimal (1) Lack of financial support; (2) unfamiliarity of patients and health care providers with the specialized occupational physician; (3) structural barriers (1) Being more independent as OPs (than an occupational physician in the company); (2) positive feedback about care, support and additional knowledge; (3) working within the clinical setting or outpatient clinic (multidisciplinary cooperation) Strengths: different survey groups; deductive guideline development; standardized evaluation procedure; second reviewer strengths/ weaknesses: qualitative expert opinions/self-assessment (no claim to representativeness)