The Psychosocial Hierarchy of Controls: Effectively Reducing Psychosocial Hazards at Work

ABSTRACT

Background

Psychosocial hazards in the workplace contribute to mental disorders, cardiovascular diseases, and musculoskeletal ill‐health. The Hierarchy of Controls applied to NIOSH Total Worker Health (TWH HOC) aims to mitigate these hazards through effective interventions. This study proposes a revision of the model resulting in a HOC for psychosocial hazards (P‐HOC) and explores its application in improving the working environment.

Methods

We reviewed recent literature on organizational and individual interventions to revise the TWH HOC to a psychosocial HOC framework. Subsequently, the modified P‐HOC was applied to a qualitative case study of nine Danish companies participating in the Danish “Agreement to problem‐solve” labor inspection strategy. We analyzed the types of initiatives implemented and gathered qualitative data on employee and management perspectives on their effectiveness.

Results

The study led to a revision of the TWH HOC resulting in a P‐HOC prioritizing organizational measures with documented effect, and indicating the importance of comprehensive measures. Findings from the qualitative study indicate a predominant contemporary focus on lower‐level P‐HOC initiatives, such as individual‐based approaches and administrative controls. While these interventions show some improvements in mental well‐being and work culture, they seem insufficient to enhance the comprehensive psychosocial environment. Companies implementing higher‐level interventions experienced greater efficacy, particularly when employing multifaceted approaches.

Conclusions

The study emphasizes the need for a more robust application of higher‐level measures and multifaceted interventions to better improve the psychosocial working environment. Future research should investigate the P‐HOC's varying impact and explore alternative frameworks for better intervention outcomes.

1. Introduction

There is consistent evidence that psychosocial hazards at work are contributing to various health problems such as mental disorders, cardiovascular diseases, and musculoskeletal health [1, 2, 3]. Focusing on mental disorders, the WHO estimates that 15% of working‐age adults have a mental disorder at any point in time and that this costs the global economy US$ 1 trillion each year due to lost productivity [4]. There is evidence that work can cause or exacerbate mental health conditions [1, 2]. Similarly, it is well established that psychosocial hazards at work have a substantial effect on musculoskeletal health; the main contributor to disability worldwide [5]. This points to the important role of working conditions as modifiable determinants of workers' health [2].

Psychosocial aspects of work include, among other factors, job content, workload and work pace, work schedule, and organizational culture, which all have associated psychosocial hazards [6]. Improving the psychosocial working environment requires that these hazards are addressed through effective measures. Schulte and colleagues (2024) from the National Institute of Occupational Safety and Health (NIOSH) recommend using the Hierarchy of Controls (HOC) applied to NIOSH Total Worker Health (TWH) (TWH HOC). The TWH HOC is a conceptual model for prioritizing effective and sustainable control measures to promote worker safety, health, and well‐being, and prioritizes organizational measures over individual measures [6, 7].

In this study, we revisit the TWH HOC in light of recent literature on the evidence for, and perspectives on, workplace interventions to improve the psychosocial working environment. This process included searching databases for studies on workplace interventions aimed at improving the psychosocial working environment, with a focus on both organizational and individual measures. Additionally, we reviewed reference lists of key studies to ensure the inclusion of significant findings. This provided a foundation for revising the TWH HOC, ensuring it encompasses existing knowledge of effective measures. Following this, we employ the revised HOC for psychosocial hazards (P‐HOC) to analyze the outcome of initiatives to improve the psychosocial working environment at nine different workplaces, participating in an “Agreement to problem‐solve” (ATP), a current labor inspection strategy in Denmark by the Danish Working Environment Authority (WEA). The analysis shows a tendency to employ particular types of initiatives relating to the P‐HOC, and examine qualitatively how employees and managers view the meaning of the implemented initiatives. Based on these assessments, we discuss the translation from the theoretical P‐HOC to actual workplace experience of the effectiveness of initiatives, leading to a discussion of rationales for employing specific types of measures. Finally, we discuss the application of the P‐HOC framework.

2. Theoretical Background

One important approach to assess the effectiveness of occupational safety and health (OSH) measures builds on the principles of the “hierarchy of controls” (HOC). This five‐level model stratifies the effectiveness of OSH measures for safety. The HOC originates in the recommendations of the American National Safety Councilin the 1950s and has been popular in chemical occupational safety research [8, 9]. Over the last years, the approach has become widespread and recognized within safety research and the study of physical strain at work [10, 11]. Recent research has thus shown that measures higher in the hierarchy more effectively prevent occupational safety problems compared to efforts lower in the hierarchy [12]. However, the HOC lacks a conceptual framework to highlight the effectiveness of specific OSH measures of the psychosocial working environment.

Schulte et al. (2024) suggest that the TWH HOC can serve as a framework for addressing work‐related psychosocial hazards [6]. This conceptual model extends the traditional OSH hierarchy to encompass controls and strategies that more broadly enhance worker well‐being [7]. The model presents strategies in ascending order of anticipated effectiveness (where 5 is the highest anticipated effectiveness and 1 is the lowest):

• Level 5. Eliminate negative working conditions and barriers to safety, health, and well‐being;

• Level 4. Substitute safer and healthier workplace policies, work processes, and practices;

• Level 3. Redesign the working environment to enhance working conditions and improve safety, health, and well‐being;

• Level 2. Educate all employees and provide resources for improved knowledge;

• Level 1. Encourage or reinforce the adoption of safe and healthy practices.

The highest levels of prevention in this HOC entail organizational interventions, whereas the lowest level entails individual approaches. Schulte et al. argue for this hierarchy by stating that organizational‐level solutions are more likely to be more efficient, have a broader impact, and be more sustainable than individual interventions [6].

3. Materials and Methods

The methods section initially covers the rationale and the methods used to revise the TWH HOC to the P‐HOC, and secondly, describes how the qualitative data used to demonstrate the application of the P‐HOC were collected. This includes an outline of the analytical approach.

3.1. Rationale for Revising the TWH HOC

The TWH HOC is a framework for managing workplace hazards, including psychosocial risks. However, during the course of this study, we identified challenges when applying the TWH HOC specifically to psychosocial hazards in the workplace.

In the context of a large evaluation of WEA's new inspection form, ATP, we applied the original HOC [10] to analyze companies' measures to mitigate their OSH problem. This worked well for musculoskeletal hazards but not so well for psychosocial hazards in the sense that the original HOC's higher levels entail measures that physically alter the working environment, which will often not be a suitable way to address psychosocial hazards. To analyze measures targeting psychosocial hazards, we employed the TWH HOC, which expands the original HOC to include controls and strategies that more broadly focus on worker well‐being [7]. When using this framework we were puzzled that traditional administrative controls, such as policies and guidelines, were placed on level 4 “Substitute health‐enhancing policies, programs, and practices.” This deviates from the original HOC, placing these measures on level 2, aligning with literature that suggests they have a limited effect in occupational safety [12]. This discrepancy between the original HOC and the TWH HOC prompted discussions within the research team on whether administrative controls are indeed significantly more effective for psychosocial hazards. Recognizing the nature of psychosocial hazards, which often require higher‐level interventions targeting root causes such as organizational culture, workload, and interpersonal dynamics, we determined that an investigation of the TWH HOC was necessary to ensure that a HOC for psychosocial hazards accurately reflects the nature of psychosocial hazards and the types of interventions effectively managing them.

3.2. Process of Revising the TWH HOC

We conducted a broad review of the literature on effective workplace interventions targeting the psychosocial working environment. To gather relevant studies, we employed a flexible and iterative approach inspired by a scoping review.

Initially, we performed searches in several academic databases, including Web of Science and PubMed, using keywords related to psychosocial hazards, workplace interventions, and health outcomes. We focused primarily on reviews and systematic reviews to gather an overview of the current evidence base.

In addition to database searches, we applied a snowballing technique by reviewing the reference lists of key articles to identify further relevant studies. This approach allowed us to capture a wide range of interventions and perspectives from the existing literature.

The results were synthesized to inform the development of the revised P‐HOC framework, ensuring that the interventions we considered were supported by knowledge of their effectiveness. The research team held several discussions to evaluate the placement of various types of interventions within the hierarchy, with a focus on aligning the P‐HOC with both theoretical models and practical considerations for addressing psychosocial risks in the workplace. Based on these steps, we developed the P‐HOC as an adaptation of the TWH HOC.

3.3. Methods Behind the Qualitative Case Studies

We collected the data as a part of a larger realistic evaluation of “Agreement to problem‐solve” (ATP), a new type of labor inspection strategy by the Danish Working Environment Authority (WEA). The WEA can offer an ATP if they suspect the presence of a complex OSH problem at a workplace, or if they find an OSH problem that is relevant to more departments or workplaces within the company. The company can decide whether to participate in the ATP or, alternatively, have the problem further uncovered by the inspector and potentially receive a notice. The ATP aims to improve the working environment of Danish companies by fostering a shared understanding of the problem and allowing the company to address the working environment problem independently, with the option of receiving help and guidance from a labor inspector [13].

The companies contributing to this study have completed an agreement to solve a psychosocial OSH problem and through this process implemented measures to mitigate their respective psychosocial OSH problems. All the companies' ATPs were approved by the labor inspector, confirming that the companies had implemented relevant measures and that the labor inspector deemed that the problem was solved. The cases were selected from a data set provided by the WEA, which contained information on all ATPs offered between 2020 and 2023. In the recruitment of the companies, we aimed to create a qualitative data set with a broad representation of the labor market; it was central to have representation of different sectors, public and private companies, and companies of different sizes. The analysis of this article is thereby based on qualitative data from public and private small, middle‐sized, and big companies from five different sectors: residential care institutions, hospitals, education, daycare, and office work. This case selection ensures a variation selection, which enables us to more clearly conclude the investigated phenomenon; “measures targeting psychosocial working environment problems,” under relatively different conditions. From this methodological approach, we expect that common features recurring in most of the nine cases will be valid under most types of legally regulated organizations in the Danish labor market. Conversely, differences between cases can be understood as phenomena that should be examined further [14]. The recruitment of the cases involved reaching out to companies via email and phone calls. We contacted 17 companies, and nine agreed to participate in the project. The nine cases are presented in Table 1.

Table 1.

Case presentation.

Case	Employees	Sector	Private/public	OSH‐problem
Case 1	35–99	Residential care institution	Public	Violence and traumatic events
Case 2	+100	Hospital	Public	High workload and time pressure
Case 3	35–99	Education	Public	High emotional demands
Case 4	+100	Daycare	Public	Unclear and contradicting demands
Case 5	+100	Office	Public	High workload and time pressure
Case 6	10–34	Daycare	Private	Violence and traumatic events
Case 7	10–34	Education	Private	Offensive acts and bullying
Case 8	+100	Office	Public	High workload and time pressure
Case 9	+100	Hospital	Public	Lack of psychological aid

The data consist of semi‐structured qualitative interviews from nine companies that have completed an ATP for a psychosocial working environment problem. In each company, the authors of this paper conducted four interviews; one with each of four roles; a manager, an employee (preferably an OSH representative), a person with legal responsibility in the company, and finally, the labor inspector from WEA responsible for the company's ATP. This triangulation allows examining the phenomenon, the companies' efforts to improve the psychosocial working environment from multiple perspectives, and enriches our understanding thereof by allowing deeper dimensions to emerge [15]. This approach leads to strong validity [15]. In two of the cases, it was not possible to interview the legally responsible person. Therefore, the final data set consists of 34 interviews. All interviews were manually transcribed. The interviews were conducted in Danish, and the quotes included in the analysis were translated into English.

3.4. Analytical Approach

The analysis of the qualitative case studies is based on a thematic analysis rooted in realist evaluation theory [16]. The analysis follows an abductive approach, where the interviewees' narratives serve as the basis for inquiry. This is an effective method to unfold a phenomenon that the researcher and the researcher's audience are not familiar with beforehand [17, 18, 19].

The analysis was focused on understanding how the interviewees describe the effect and meaning of the implemented measures in each company as well as the mechanisms that make each of them work. By applying this approach to the analysis, we gain the opportunity to describe what measures were implemented, how they worked, and under what circumstances. Based on a discussion of these themes in the project group, we developed a coding tree in NVivo 12 encompassing the companies' measures and their experiences of the measures' effect. The codes were broad to encapsulate as many perspectives as possible. First, we reviewed each case‐company and compiled detailed case reports. Subsequently, the project group conducted a comparative analysis of the case reports summing up similarities and differences across cases and exemplifying these in the final analysis. The analysis is structured according to the HOC, first by placing the companies' measures in the five levels of the hierarchy, to assess the expected effectiveness of the measure. Second, examining the measures implemented at each level and the interviewees' perception of their effect. We use this insight to discuss the interviewees' empirical and qualitative‐based experiences against the theoretical and already published insights as described in the previous sections.

4. Results

In the results section we will first present existing knowledge of organizational and individual interventions, then we link this knowledge of effective interventions on psychosocial working environment to the TWH HOC and present our revised version of the framework, the P‐HOC. Following this, we demonstrate application of the P‐HOC by analyzing the measures implemented by the companies and their experiences of their effect.

4.1. Organizational Interventions

Organizational OSH interventions seek to assess, modify, mitigate, or remove work‐related psychosocial hazards in work targeting groups or the entire organization [4]. They are designed and implemented at the organizational level and aim to modify workplace policies, practices, and environment to improve the employees' mental health. Organizational OSH interventions are recommended for the prevention of stress within organizations (see e.g., [4, 20, 21, 22]). However, systematic reviews show that these interventions do not always have the intended outcomes [22, 23]. This may be explained by the fact that organizations are complex systems and the success of the interventions is influenced by the internal and external organizational context, the intervention and its implementation, and the participants' perception of the intervention [4, 24].

Some organizational measures have, however, been found effective. For example, there is high‐quality evidence that measures that directly reduce employee's workload, increase their available time or physical resources, and thereby reduce the quantitative demands of work can have an effect on burnout [20, 25, 26]. There is also high‐quality evidence that measures changing the working time arrangement—especially those that give employees more influence on scheduling their working time—have positive effects on work environment outcomes [2, 20, 27].

Several organizational measures, including institutional, strategic, or policy‐oriented interventions, have limited direct evidence for their effectiveness in enhancing psychosocial well‐being at work. An example of such measures is organizational action plans, and their value mainly lies in the structures they uphold and the beliefs, practices and feelings they reinforce, rather than in their capacity to prevent negative OSH outcomes [28]. While studies indicate that action plans may increase job resources, they may also correspond with increased job demands and reported work‐related stress [29, 30]. Therefore, their effectiveness in reducing work‐related stress might be limited if they do not prioritize primary interventions that address the root causes of stress in the work environment [29, 30].

4.2. Individual Interventions

There is more consistent evidence on the effect of individual interventions than organizational interventions [3, 24, 31]. This is most likely becausestudying the effects of individual interventions is more accessible; companies are generally more reluctant to implement organizational interventions which may be more costly, time‐consuming, or change‐oriented [20, 32]. This provides stronger opportunities for evaluating their effectiveness. As a result, individual oriented interventions are often supported by higher‐quality studies, such as randomized controlled trials [3]. Individual interventions focus on personal skills and resources to cope with stress and enhance one's own psychosocial well‐being. One such intervention is mindfulness interventions, which show consistently positive effects on stress reduction and mental well‐being [31, 33]. Similarly, high‐quality reviews show positive effects on mental health outcomes of education and information provision interventions, which are defined as strategies to raise awareness of mental illness and how to manage it in workplaces [31]. There is also high‐quality evidence for individual psychological therapies, which points to a positive effect on stress reduction, mental illness, and mental well‐being [31, 33].

The evidence of other individual measures' effect is less strong. For example, there is low‐quality evidence for the effectiveness of introduction programs for newly graduated employees, including mentoring programs [20]. Similarly, there is low‐quality evidence for measures to improve employees' skills and job satisfaction [20], and the evidence base is also low for employee skill development [2, 4]. Management support may have a positive effect because it leads to more knowledge and competencies among managers, but the evidence to which degree this leads to improvements for the employees is less clear [4, 20].

4.3. Rephrasing the HOC for Psychosocial Hazards

There is stronger evidence for individually targeted interventions than organizational interventions. However, as researchers and the WHO argue, this does not necessarily represent the primary drivers of a healthy psychosocial working environment [2, 3, 4, 20, 34]. Instead, it may illustrate that it is easier to implement individual interventions because these face fewer challenges than organizational interventions [6, 34].

We argue that organizational measures with moderate to strong evidence are placed on the highest levels of the HOC for the psychosocial working environment similar to the TWH HOC and the original HOC, which is based on similar principles [9]. These primary preventive measures create systemic changes that benefit all workers and are more likely to have a broad and sustainable impact [6]. By contrast, individual approaches often have limited reach and depend on personal motivation and resources. In addition, individual approaches place the burden on the worker for their success or failure. By addressing workplace factors, organizational measures can prevent issues from arising, reducing the need for individual interventions. Moreover, national policies and regulations, a determinant of organizational measures, are the key drivers for effectively managing psychosocial hazards at workplaces [35]. Most importantly, we believe that workers should not have to adapt to harmful working conditions; rather, employers should create working conditions where people can stay healthy.

Further, we argue that administrative measures should be placed lower in the hierarchy than suggested in the TWH HOC. This aligns with the original HOC and resonates with the perspectives identified in the literature, which indicate that administrative measures such as policies and action plans can be central to communicating, raising awareness, and making small improvements. The measures can set a direction for the organization, which can lead to actions that can improve the working environment, but policies and strategies are not necessarily effective measures in their own right [29, 30]. Therefore, this study is sensitive to the fact that companies may implement policies, action plans, guidelines, risk assessments, or other measures that can be effective contributions to addressing the psychosocial working environment. The lack of evidence of the effectiveness of company policies, action plans, guidelines, etc. on mental health outcomes does however incentivize us to place these measures lower in the hierarchy than suggested by NIOSH, who place such policies and strategies at level 4.

In the following, we define the revised version of the TWH HOC, the P‐HOC, by categorizing interventions from the literature, based on the perspectives discussed and the knowledge supporting their effectiveness.

At level 5, we place measures that directly reduce employees' workload, increase their available time or physical resources, and thereby reduce the quantitative demands of work. This aligns with the TWH HOC, and we follow their phrasing “eliminate working conditions that threaten safety, health, and well‐being.” An important note regarding level 5 of the P‐HOC is that not all psychosocial hazards can be eliminated. The P‐HOC is therefore designed as a flexible framework, allowing organizations to aim as high in the hierarchy as possible and necessary based on the specific context and character of the issue that they are trying to address. This flexibility ensures that while complete elimination of some psychosocial hazards may not be feasible, organizations can still implement the most effective interventions available, adapting the framework to fit their unique work environments and challenges. Measures characterized at this level can be removing the sources of psychosocial risk entirely (e.g., eliminate harassment, bullying, and excessive workloads), or reducing the quantitative demands (e.g., hire more staff, or give additional resources to the workplace).

At level 4, we place organizational measures that change the working time arrangement—preferably those that give employees more influence on scheduling their work time—balancing the employees' influence and demands. This placement relates to the TWH HOC, where influencing working time may be a way of increasing the employees' influence and thereby giving them more flexibility, which changes the relationship between demand and control for the employees. Similarly, it can reduce contradictory demands from, for instance, family life and work. We remove administrative controls such as policies from level 4, differentiating the P‐HOC from the TWH HOC. Therefore, we argue that this level should be rephrased from “substitute health‐enhancing policies, programs, and practices” to “substitute safer and healthier work processes and practices.” Measures at level 4 replace harmful practices with those that promote mental health (e.g., substitute rigid schedules with flexible working hours, introduce job rotation to reduce monotony and strain).

At level 3, we stick to NIOSH's phrasing of “redesign the work environment for safety, health, and well‐being'.” This entails organizational measures such as management support, since managerial support is an organizational measure aimed at assisting and helping employees prioritize or evaluating demands, but of a more opaque and generally subjective character than for instance demand‐, or working time reduction. This level of the HOC also entails measures that redesign the physical or organizational environment aimed at improving psychosocial well‐being. Measures at this level modify the physical and social working environment (e.g., improve ergonomic design, create collaborative spaces, noise reduction, enhance lighting and ventilation), or foster a supportive work culture (e.g., team‐building activities, inclusive leadership practices).

At level 2, we place strategies, policies, guidelines, and other communicative practices within the company. This aligns with the original HOC, but differs from the TWH HOC. We argue that these measures should be placed on level 2—at least until stronger evidence for their effectiveness or role in creating effective measures is revealed. Following this, we argue that level 2 of the P‐HOC should be rephrased from “educate all employees and provide resources for improved knowledge” to “administrative controls—company strategy, policies, communicative practices and guidelines.” Measures at level 2 include developing and implementing organizational strategies and guidelines that promote mental health (e.g., stress management programs, clear communication channels, and mental health awareness campaigns), and ensuring these strategies and guidelines are well‐communicated and accessible to all employees (e.g., regular training sessions, employee handbooks).

At level 1 of the P‐HOC, we place individual measures such as mindfulness interventions, information provision interventions, and individual psychological therapies. While these measures have been found effective in reducing stress and improving mental well‐being, these should be viewed as supplementary to comprehensive organizational strategies. This placement of individual measures aligns with the original HOC and the TWH HOC, in which encouragement of personal change is on the lowest level of the hierarchy. We argue that the lowest level in the P‐HOC is phrased the same as in the TWH HOC “encourage personal change'.” Measures at this level provide resources for individual‐level interventions (e.g., mindfulness training, individual psychological therapy, resilience training), or encourage personal development and self‐care practices (e.g., work‐life balance, healthy lifestyle choices).

Further, there is high‐quality evidence that the more comprehensive a measure, the greater the potential for impact [3, 4, 6, 33], and the combination of organizational and individual approaches may be particularly efficacious [2, 36]. This is a very important notion, suggesting that psychosocial interventions should focus on a broad complement of risk management strategies for complex contexts and hazards. These insights indicate that a P‐HOC must encompass this overarching approach to solving psychosocial hazards. Below, we present the P‐HOC model, which incorporates these principles to guide the development and application of effective psychosocial measures in the workplace.

The P‐HOC presented here integrates this understanding, highlighting the need for comprehensive, multilevel interventions (Figure 1). It builds on the TWH HOC by prioritizing organizational‐level measures while recognizing the importance of complementary individual‐level interventions. The P‐HOC provides a flexible framework that organizations, inspectors, and others can use to guide their efforts in addressing psychosocial risks. It emphasizes the need to implement controls as high in the hierarchy as possible, preferably on different levels of the hierarchy, depending on the specific nature and context of the OSH issue.

Figure 1.

The psychosocial hierarchy of controls.

The following table presents the differences between each level of the three hierarchies of controls presented in this paper; the original HOC, the TWH HOC, and the P‐HOC (Table 2).

Table 2.

Differences between the original HOC, the TWH HOC, and the P‐HOC.

	Original HOC	TWH HOC	P‐HOC
Level 5	Elimination—Physically remove the hazard	Eliminate working conditions that threaten safety, health, and well‐being	Eliminate working conditions that threaten safety, health, and well‐being
Level 4	Substitution—Replace the hazard	Substitute health‐enhancing policies, programs, and practices	Substitute safer and healthier work processes and practices
Level 3	Engineering controls—Isolate people from the hazard	Redesign the work environment for safety, health, and well‐being	Redesign the work environment for safety, health, and well‐being
Level 2	Administrative controls—Change the way people work	Educate for safety and health	Administrative controls—Company Strategy, policies, communicative practices, and guidelines
Level 1	PPE—Protect the worker with personal protective equipment	Encourage personal change	Encourage personal change

4.4. Application of the P‐HOC on Qualitative Case Studies

In the following section, we employ the P‐HOC to analyze the implemented measures to mitigate psychosocial OSH problems at nine companies, participating in an ATP. The nine companies implemented 37 measures in total, to accommodate the ATP. These measures are placed in the P‐HOC alongside the managements' and the employees' perspectives of the measures' effect, presented in Table 3.

Table 3.

Placement of the companies' measures and the managers' and employees' experience of the measures'effect.

Case	OSH problem	Implemented measures	Level in the hierarchy of controls	Management perspective	OSH‐representative/employee perspective
Case 1 (residential care institution)	Violence and traumatic events	Common definition of violence and threats	2	Strengthens the understanding of employers and employees. They were happy to live up to WEA's demands in every way.	It did not make a difference; employees perceived the violence as a fundamental work condition.
Case 2 (hospital)	High workload and time pressure	‐ Hired more nurses	5	The social dynamics have improved, and the restructuring has improved the working environment. However, it is an ongoing process.	Big impact—especially in the beginning. However, it has to be maintained.
		‐ Restructured patient courses	4
		‐ Divided staff into smaller teams	3
		‐ Put up posters	1
Case 3 (education)	High emotional demands	‐ Implemented a practice for recording violent incidents	2	The culture in the employee group has changed. Some things cannot be changed, but the measures have enhanced the psychological security of the employees.	Positive impact, more focus, and practice have changed for the employees.
		‐ Team meetings	2
		‐ Supervision	1
		‐ Regular meetings between management and supervisors	2
		‐ Updated violence policy	2
		‐ Professional development of employees	1
		‐ Risk assessment of students	2
Case 4 (daycare)	Unclear and contradicting demands	‐ Converted coordinators into team leaders	3	They do not agree, one does not think the measures had a big impact. The other think that it has helped but there are still issues.	Positive impact, still issues, the biggest change has been the restructuring of management.
		‐ Developed job descriptions	2
		‐ Onboarding programs	1
		‐ Framework for collaboration	2
Case 5 (office)	High workload and time pressure	‐ Hiring of staff to relieve management workload	5	They have come a long way but it has to be a continuous focus in the organization. The restructuring of the work has improved the working environment.	The measures have been effective and the working environment has been improved. Underlines that it has to be a continuous focus.
		‐ Hiring of new staff	5
		‐ Resources for a project to facilitate and clarify tasks	5
		‐ Goals considering available resources	2
		‐ Written guidelines for work quality expectations	2
		‐ Reevaluation of work distribution	3
		‐ Overview of workload and workflow	2
Case 6 (daycare)	Violence and traumatic events	‐ Hired more staff	5	Improved working environment.	Improved psychological safety. They have implemented measures that give the employees a feeling of being in control.
		‐ Reconstruction of physical premises for increased safety	3
		‐ Improvement of resident well‐being assessment forms	2
		‐ Training in the use of force	1
		‐ Appointment of local OSH representative	2
Case 7 (education)	Offensive acts and bullying	‐ Appointment of OSH representative	2	Giving a sense of psychological security to the employees but it has not made a big difference.	Improved working environment, but has to be an ongoing focus.
		‐ Development of personnel policies including anti‐bullying, anti‐disparaging language, and anti‐harassment policies	2
		‐ Implementation plan for personnel policies	2
Case 8 (office)	High workload and time pressure	‐ Conducted workshops with employees and joint sessions with management and employees	2	Improved working environment, but not sure what caused this. Fewer employees on sick leave.	The working environment has improved but there is still a lot that could be done.
		‐ Developed an action plan to provide an overview of various issues	2
Case 9 (hospital)	Lack of psychological aid	‐ Establishment of coordinator roles	3	Improved working environment, fewer employees on sick leave. More respect for the traumatic incidents.	Improved working environment
		‐ Appointment of key personnel	3
		‐ Training for all employees	1
		‐ Debriefing after traumatic incidents	1
		‐ Access to consultations with a crisis psychologist	1

4.5. Level 1 of the P‐HOC: Encourage Personal Change

The lowest level in the P‐HOC consists of measures encouraging individual change for improvements to well‐being. Five companies implemented this type of measure, through putting up posters, onboarding programs, training, supervision, and access to psychological aid—measures with varying evidence of effect. All of the companies that implemented individual measures placed on level 1 of the P‐HOC also implemented measures on other levels of the P‐HOC, thus they have combined individual and organizational measures—an approach that has been found effective in improving the psychosocial working environment.

As an example, Case 9, a hospital, implemented three measures on level 1; debriefing after traumatic events, access to consultations with a crisis psychologist, and training for all employees, which consisted of a course on how work can cause mental strain. These are all measures with high‐quality evidence of effect. They also implemented two measures on level 3; redesigning the working environment. The management and the OSH representative agree that the measures have had a positive effect on the working environment. For example, the manager reports that absenteeism has decreased:

“What impact would you say it has had on the work environment?

There aren't as many critically ill, like those who have been sick, etc. I'm just wondering if we've gotten the last person back. I actually don't know. I think, at the time when we did these things, there were about 5–6 people who were on sick leave due to stress and due to traumatic incidents. But I think we have one now, I mean, long‐term sick leave.”

(Manager, case 9)

The manager reports that the number of long‐term sick leaves has decreased significantly, which he sees as a good indicator that employees are getting help in time after experiencing a traumatic incident. While the empirical material makes it hard to determine whether level 1 measures are effective because of the combination of measures in all cases, there are indications that they may improve the working environment in concerted efforts.

4.6. Level 2 of the P‐HOC: Implement Administrative Controls

Administrative controls such as developing strategies, policies, and guidelines or educating the employees to enhance knowledge are placed on the second level in the P‐HOC. Eight out of nine companies implemented this type of measure, accounting for almost half of the total number of implemented measures.

Three companies only implemented measures on level 2 of the P‐HOC. Case 1, a residential care institution, implemented a common definition of violence and threats to accommodate the agreement to problem‐solve. The manager expressed that the definition had a positive outcome on the dialogue about violence at the workplace but he believed that the measure was redundant:

“Sometimes it seemed a bit unneeded because we are actually quite sharp on it. We just didn't have it in writing, and in fact, the handling of those situations that arise is excellent, if I do say so myself. So, it just became a bureaucratic formality that needed to be sorted out.”

(Manager, case 1)

The manager here describes that the company did not need the definition since their practices for violence and threats were well‐functioning. He states that he is satisfied that the company now fulfills all of the WEA's requirements for handling violence and threats at work. This is the manager's perspective, which is not reflected in the employee's view of the outcome. Rather, the employee from the same company described that the measure made no difference for the psychosocial well‐being at the company and that violence is an inherent part of the job. This example characterizes measures on the second level of the P‐HOC in our case study. Some companies implemented similar measures and experienced that they have had positive outcomes on work processes but are still having difficulty with the same psychosocial problems that the ATP was targeting. Case 7, a school, implemented three measures on the second level of the P‐HOC, and the management experienced that it gave some sense of security for the employees but did not make a significant difference in practice. The employee spoke more positively of the effects and said that the measures have improved the working environment but emphasized that it has to be an ongoing focus. Case 8 implemented two measures on level 2 of the P‐HOC, and the management and the employee agreed that the working environment has been slightly improved but that there is still a lot of work to be done. However, the manager said that fewer employees are on sick leave now than before the measures were implemented. Case 3, a school, implemented a high number of measures (seven) to address the issue of high emotional demands. Five of these measures are on the second level in the P‐HOC, and the last two measures are on level 1. The management and the employee found that the measures improved the working environment.

Administrative measures, placed on the second level of the P‐HOC, have had varying outcomes in the companies. Differences in the companies' context, the character of the measures, how they were implemented, and whether and to what extent the measures were multifaceted can explain this variation.

4.7. Level 3 of the P‐HOC: Redesign the Working Environment

Five out of nine companies implemented organizational measures on levels 3–5 in the P‐HOC. In total, measures on the three highest levels represented around 30% of the implemented measures.

The third level in the P‐HOC entails measures aimed at redesigning the working environment to enhance working conditions and improve safety, health, and well‐being. Three companies implemented measures of this sort. Two of these companies redesigned the organization of work, the third company redesigned the physical premises. Case 9 implemented two measures on level 3 and three measures on level 1 of the P‐HOC. They agreed that the working environment was improved, and the manager said that fewer employees are on sick leave than before the measures were implemented. Case 4 implemented one measure on level 3, two measures on level 2, and one measure on level 1 of the P‐HOC. They disagreed internally on what the outcome of the measures was. The highest level of management thought that the measures had no effect, whereas the lower‐level manager and the employee thought it had a slight impact. They mentioned that the measure of restructuring the management made a direct difference.

4.8. Level 4 of the P‐HOC: Substitute Work Processes and Practices

The fourth level of the P‐HOC involves replacing unhealthy working conditions or practices with safer health‐enhancing programs and management practices that improve the culture in the workplace. Three companies implemented this type of measure. These included restructuring patient courses and restructuring the management. These measures are placed on the fourth level because there is evidence that restructuring the work and thereby limiting the exposure to the task with inherent risk, has a positive effect on the psychosocial working environment—especially when the employees are involved in the restructuring. Case 2, a department at a hospital, implemented measures on levels 1, 3, 4, and 5. They hired new staff and involved the employees in restructuring the organization of the work. The OSH representative explains how they have reorganized the teams:

“Well, they [we, the employees] are always involved. We have created new teams. We divided them into Team One and Team Two. This means that it is now a bit more down‐to‐earth. Before, we were just one big team, where all 60 on duty had to cooperate on when to take breaks and which rooms and patients to attend to. We have now split it up, so we are smaller teams. And in those teams, they manage their breaks, for example. They find it easier to communicate because they sit together.”

(OSH‐representative, case 2)

The employees have gained greater influence in the organization of their working time by splitting the department into smaller teams where the employees structure their breaks themselves. The management and the employee agreed that the social dynamics of the workplace and the general working environment improved and they emphasized the restructuring of the work as especially efficacious.

4.9. Level 5 of the P‐HOC: Eliminate Negative Working Conditions

The fifth, and highest, level in the P‐HOC consists of measures that eliminate workplace conditions negatively affecting well‐being. Two companies implemented this type of measure by supplying additional resources or hiring new employees or managers. These measures are placed on the highest level of controls because they improve the balance of the work by reducing the quantitative demands of the work, which is a well‐documented, effective way of minimizing psychosocial hazards. Case 6 implemented one measure on level 5, one measure on level 3, and three measures on level 2 of the P‐HOC. The management and the employee agreed that the working environment and the feeling of safety were improved. Case 5 also hired new staff and implemented several measures on lower levels of the P‐HOC. The management and the employee agreed that the measures had a big impact on the psychosocial working environment and found that the restructuring of the work was an effective measure. The management and the employee, however, emphasize that it has to be a continuous focus because the employees still face a high workload.

The companies that implemented measures on level 3–5 of the P‐HOC also implemented measures lower in the hierarchy. Thereby the mechanisms at play are multifaceted measures; organizational and individual, or administrative and on different levels of the P‐HOC. The outcome for the companies is that the measures have limited the employees' exposure to the psychosocial hazards that motivated the measures.

5. Discussion

This study contributes to the modification of the HOC for specific application to psychosocial hazards and takes steps to promote the establishment of empirical approaches to investigating and evaluating initiatives to improve the psychosocial working environment with this notion of effective measures. This may be highly important to researchers aiming to understand initiatives to improve the psychosocial working environment. Working environment authorities and labor inspectors may use these insights to enhance the visibility and legitimacy of their work, and organizations and OSH professionals may apply this approach to ensure the effectiveness of their OSH practices.

We revised the TWH HOC by categorizing existing literature on effective measures in the levels of the hierarchy. This process led to a revision of the fourth and second level of the TWH HOC, and an additional overarching component, resulting in the following P‐HOC:

Implement comprehensive, multi‐faceted, and context‐specific measures, and

• Level 5. Eliminate working conditions and barriers to safety, health, and well‐being;

• Level 4. Substitute safer and healthier work processes and practices;

• Level 3. Redesign the work environment for safety, health, and well‐being;

• Level 2. Administrative controls—strategy, policy, communicative practices, and guidelines;

• safety, health, and well‐being; and

• Level 1. Encourage personal change.

We applied this P‐HOC to a qualitative case study of nine companies. We investigated measures implemented to combat problems in the psychosocial working environment by placing the measures in the P‐HOC and reviewing the companies' experiences of their effect. In doing so, we find that the vast majority of the implemented measures are categorized within the lower levels of the P‐HOC. This indicates that companies prioritize administrative and individual solutions to psychosocial working environment problems. While these measures may improve the mental well‐being of individual workers and contribute to a shift in the work culture, they may not be sufficient to improve the psychosocial working environment in general.

One reason why companies mainly implement measures of individual and administrative character may be that these are easier to implement [3, 24]. Organizational‐level interventions are more likely to encounter contextual and procedural factors that hinder their success. Implementing organizational interventions is a complex process and the success of the intervention is influenced by conditions such as organizational context, the character of the interventions and their implementation, and the workers' view of the intervention. This complexity also explains why organizational interventions tend to have a lower success rate than individual‐level interventions [24].

Another reason why the implemented measures are mainly reserved for individual and, especially, administrative controls can be, as proposed by Rae and Provan (2019), that the measures can serve the purpose of ‘demonstrated safety’ [28]. Examples of such measures are policies and guidelines, which are integral parts of a structured approach to ensuring and demonstrating occupational safety and health to external stakeholders. Measures with this purpose are oriented towards showing that the organization is meeting its safety obligation and increases as regulators and other external stakeholders need to be convinced [28]. The companies in this study implemented the measures to fulfill the ATP. Hence, it is plausible that the companies have been oriented toward administrative controls to demonstrate safety.

The analysis shows that the companies' experiences seem to corroborate results garnered from the literature; that multi‐faceted, comprehensive measures were more effective than narrow‐focused measures, that a combination of individual and organizational‐oriented approaches was perceived as effective, and that the companies who implemented measures higher in the P‐HOC found the measures effective. The companies particularly highlighted the efficacy of restructuring efforts, whether related to working hours or management.

The companies' experiences of the effect of the measures support the evidence that the more comprehensive a measure is, the greater the potential for impact, and that administrative control measures have a limited effect in their own right. The experiences of the companies that implemented several measures, where at least one of them was not an administrative control measure, resonates with the evidence that implementing several measures at different levels of the P‐HOC is an effective approach to improving the psychosocial working environment. The fact that the companies who only implemented measures on level 2 did not find them very successful aligns with the argument for placing administrative controls on level 2; that they cannot change the working environment in their own right.

It is relevant to highlight that there were divergent perspectives on the effect of the measures within some companies. This underlines the complexity of measuring the effect of measures to improve the psychosocial working environment.

5.1. Discussion on the Application of the P‐HOC Framework

The P‐HOC framework is designed to serve as a flexible guide for labor inspectors, OSH professionals, OSH representatives, and organizations in addressing psychosocial hazards. While the hierarchy encourages aiming for higher‐level controls, such as the elimination of hazards (Level 5), it is important to acknowledge that not all hazards can be addressed at the same level. The type of psychosocial hazard in question often determines which level of control is most appropriate.

For instance, psychosocial hazards such as excessive workloads can be addressed by level 5 measures—eliminate negative working conditions and barriers to safety, health, and well‐being—as exemplified in the results section. However, in cases where the hazard involves the absence of psychological aid or inadequate social support, as the example in case 9—or if elimination of a hazard would involve elimination of the option of performing work, since alternatives do not currently exist—a higher‐level control may not practically applicable. In these instances, interventions from Levels 1–3, which include support systems and organizational policies, may be more fitting. Further, this study highlights the importance of comprehensive and multi‐facetted measures and thereby the need for a nuanced understanding of the psychosocial risk in play, ensuring that the interventions align with the specific needs of the workplace. The P‐HOC framework should be seen as a flexible tool that guides organizations toward the most effective interventions possible for the given risk factor, rather than a rigid system where every psychosocial hazard must be solved at the highest level of control. This study indicates great relevance for future research to dig deeper into the varying effects of measures at different levels of the P‐HOC. By stratifying the measures, we conceptualize the effectiveness of measures targeting the psychosocial working environment. This works as a tangible tool for labor inspectors, OSH professionals, OSH representatives, and organizations to assess whether their measures can make a difference for the psychosocial environment in workplaces. Also, future research could fruitfully apply and test the framework for evaluation of working environment initiatives in larger intervention studies or studies mapping out working environment initiatives in companies, and quantitatively examine the relationship between the level of measures on the P‐HOC and outcomes such as influence, stress, sickness absence, depression, and work ability.

5.2. Limitations

Despite the valuable insights provided in this study, several limitations must be acknowledged. Firstly, our review of existing literature was not exhaustive. Consequently, there may be evidence of measures that could influence our findings. Secondly, the empirical evidence presented is of moderate quality, and it is important to note that the companies' interventions were motivated by their participation in the ATP. Thus, our conclusions should be interpreted as indicative rather than definitive. Further research is necessary to investigate the levels of the P‐HOC more comprehensively.

Moreover, our hierarchy places individual measures at a lower level, similar to the original HOC and the TWH HOC, this placement reflects the principle that organizational measures hold greater weight in creating and sustaining a safe workplace. Individual measures can contribute to health and well‐being but are not the primary strategy for mitigating psychosocial hazards. However, some discussion exists within the field about the quality and effectiveness of organizational versus individual measures. Future research should continue exploring how these measures function together within the hierarchy, further clarifying their roles in psychosocial interventions.

It is also important to recognize that our approach involves a simplification of highly complex processes. This simplification inevitably overlooks some of the nuances involved in measures and interventions related to the psychosocial working environment.

Author Contributions

Asta Kjærgaard and Jeppe Zielinski Nguyen Ajslev conceived and designed the study. All authors participated in the acquisition, interpretation, and analysis of data. Asta Kjærgaard drafted the work. All authors were part of revising the work critically for important intellectual content. All authors provided final approval of the version to be published. All authors agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Ethics Statement

According to Danish law, qualitative interview studies need neither approval by ethical and scientific committee nor informed consent. All data were deidentified and analyzed anonymously.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are not available due to privacy or ethical restrictions.