Any large-scale disaster induces fear, panic, sadness, despair or confusion not only to its direct victims and their families, but also to the local community and even the entire country. On the other hand, it also triggers healing-community reaction [1] seeking recovery and reconnection amidst crisis and chaos. Like many volunteers who work hard to restore their community, mental health professionals such as psychologists, psychiatrists, nurses, and social workers make a concerted effort to help survivors, family members, and others in the disaster area. Disaster mental health (DMH) workforce members can contribute to the recovery of survivors in their respective expertise and competence areas. Education and training are essential for them to play their roles well in disaster situations. Emphasis should therefore be placed on strengthening their expertise and competences as well as increasing a sense of responsibility for DMH services.

Competence can be to be understood as the effect that “a professional is qualified, capable, and able to understand and do certain things in an appropriate and effective manner” [2]. Competence is made up of a variety of elements, which can be summarized, for example, into what a person brings to a job or role (knowledge), what the person does in the job or role (performance), and what is achieved by the person in a job or role (outcomes) [3,4]. Recently, it has become a trend to extend the concept of competence by including ethic, value, and attitude that go beyond the scope of knowledge and skills [5-7]. The goal of education and training is to promote and develop these various competences, and the field of DMH is no exception.

The core competences required for disaster response are the elements essential for effective disaster-related task performance. In this regard, the Guidelines for International Trauma Training by ISTSS/RAND [8] present a series of rules and strategies that can be used as a basic framework for training lay health workers as well as professionals. The core elements of a DMH workforce training program are values and beliefs, contexts and systems, and an evidence-based curriculum [8]. DMH services involve experience and knowledge sharing in the traditional mental health field and require collaboration with other professionals, public officials and volunteers who have differing backgrounds and expertise. For this reason, organizational competences, in addition to individual competences, might be of vital importance in the field of DMH.

Many researchers have placed emphasis on the organizational competences of a DMH workforce, such as communication,9,10 leadership at extreme crisis [11], collaboration with other professionals [12,13], and teamwork [10]. Additionally, ethical competence is very important, given that DMH workforce members should deal with the existential and spiritual issues of the survivors, family members, and people in the community in extreme circumstances [8]. Therefore, a DMH workforce training and competence enhancement program should cover not only individual knowledge and skills but also ethic, attitudes, and values required of them as disaster survivors’ advocates and care providers, as well as organizational competences such as teamwork, leadership/followship and conflict management.

Thus far, core competences have been proposed for general healthcare or public health professionals and students, with focuses on psychological support and intervention as well as comprehensive disaster preparedness and response [9]. Regrettably, however, a scale for measuring core competences required of DMH workforce members, covering both individual and organizational competences, has yet to be developed. The delay in developing a DMH workforce competence scale may be ascribed to a number of reasons. First, the history of disaster is long, but the history of disaster research is relatively short. DMH is an emerging field with a short history compared with other disciplines. Therefore, it was not until recently that researchers became aware of the importance of the competences required of DMH workforce members and began to take interest in developing comprehensive and systematic training curricula. Accordingly, it is rather rarely the case that DMH or disaster psychology is offered as a required subject in the undergraduate or postgraduate curriculum of the related departments such as psychology, psychiatry, nursing and social work, and in the training courses for acquisition of professional licensure. However, the importance of the DMH field has been continually emphasized by several scholars [7,9], and each large-scale disaster has prompted increased attention to DMH. The second reason is associated with the lack of consensus on the definition of disaster response competences required of DMH workforce members. Related professionals, such as psychologists, physicians, nurses, and social workers, have their respective expertise and orientations, which makes it difficult for them to reach a consensus on common core competences in disaster situations. Whereas a few scales have been developed to measure the core competences in emergency nursing or urgent care situations [13-15] and emergency medicine [16], the core competences required of mental health professionals have not been established, still less a scale to measure them. Nonetheless, there is a growing demand for competence enhancement of the DMH workforce [17] with a constantly raising awareness of the need of developing an assessment tool to measure them.

Competence can be estimated with a fair degree of accuracy by objectively assessing the level of knowledge or skill-based performance, or by measuring the perceived competence, i.e., competence-related self-efficacy. The DMH competences can be accessed from a multidimensional perspective including a self-report and an observer rating methods and at individual and organizational levels. Perceived self-efficacy is one of the essential components for multidimensional assessment of the DMH competences. Workers with a high perceived competence are more likely to respond efficiently in actual disaster situations than those with a low perceived competence: there is a reciprocal relationship between actual response competence and perceived competence, i.e., the higher the former, the higher the latter [18,19]. Thus, the current study was intended to develop the Perceived Competence Scale for Disaster Mental Health Workforce (PCS-DMHW), a self-reported scale focusing on perceived competence related to disaster response, and to test its validity.

In Addition, most of the disaster response competence scales measure general competence without differentiating between individual and organizational competences. For example, in the study by Al Thobaity and colleagues [15] who developed a scale measuring the disaster nursing core competences, three factors were extracted, namely, core competences of disaster nursing, barriers to developing disaster nursing and nurses’ roles in disaster management. Of them, the core competences of disaster nursing include mitigation and planning and preparedness and response core competences. The Disaster Response Self-Efficacy Scale [14] for measuring nursing students’ disaster response competences consisted of disaster on-site rescue, disaster psychological nursing, and disaster role quality and adaptation. Notably, contrary to previous scales, the new PCS-DMHW has been designed to measure the perceived competence of both DMH professionals and lay health workers at the organization level, in addition to individual competences.

To sum up, this study pursues two objectives: 1) to develop a PCS-DMHW measuring the DMH workforce’s perceived core competences at both individual and organizational levels and 2) to test the construct validity and criterion-related validity of the PCS-DMHW using the empirical data collected from DMH workforce members.

This study was conducted to develop and validate the PCS-DMHW, a scale capable of measuring the perceived core competences of DMH workforce members at individual and organizational levels. This self-reported scale includes 24 items classified into four subscales of individual competences (knowledge and skill, ethic, personal qualification, and calling), 27 items classified into three subscales of organizational competences (teamwork, network, and followship), and three items pertaining to one supplementary scale (prevention of burnout).

In the process of testing the content validity of the theoretical model of the PCS-DMHW, the individual competences, which were classified into three sub-competences of DMH support-related knowledge, skills required for disaster response, and essentially required attitudes, were reclassified through EFA into four factors as follows: knowledge and skill were extracted together as a single factor, and attitudes were distinctively categorized into three factors of ethic, characteristic, and calling. These four individual competence factors were also verified by CFA.

The knowledge and skills items within the individual competences scale were extracted into one factor in the EFA. This result suggests that knowledge and skills are regarded theoretically as separate concepts, but the two operated interactively in disaster response situations, instead of independently from each other. Contrary to our expectations, the items pertaining to the subscale “prevention of burnout” as part of individual competences were excluded from analysis because they failed to be grouped together into a single factor and the overall model fit was poor when they were included in the CFA. Despite the insufficient statistical relevance of the ‘prevention of burnout’ subscale, it was decided to retain the related items as a supplementary subscale for future studies in consideration of the absolute importance of preventing of burnout at disaster situations.

As regards the organizational competence scale of the PCS-DMHW, three factors of teamwork, network and followship were found to be appropriate theoretically and empirically fit in both EFA and CFA. Among the organizational competences essential when working at disaster sites, leadership, communication, cooperation and conflict management were grouped together into the factor ‘teamwork’, resource networking and disaster administration into the factor ‘network’, and followship was classified as a separate single factor. In the theoretical model of the PCS-DMHW, leadership and followship were assumed to form one factor related to human resource management, but the leadership factor was included in the teamwork scale measuring communication, cooperation and conflict management in the final model. The ‘teamwork’ scale of the PCS-DMHW is also in good agreement with the findings of previous studies, according to which the most common teamwork component is the informationsharing communication among team members [29,30] and team leadership is the decisive factor for promoting effective teamwork [31,32]. I Inclusion of the ‘network’ and ‘followship’ subscales in the PCS-DMHW is considered to be associated with the specific situation of disaster. The ‘network’ subscale reflects well the importance of networking the human and material resources generally scarce in disaster situations and the need for administrative competence for resource networking. The scale labeled ‘followship’ refers to the ability to follow leaders’ instructions and accomplish the task assigned.

Correlation analysis was performed to test discriminant and convergent validity, whereby it was anticipated that subscales within the PCS-DMHW, either individual or organizational, would have higher correlations. While the interscale correlation of the PCS-DMHW was found to be fairly high, the subscales at the individual level showed high positive correlations not only with other individual competences, but also with organizational competences. Interestingly, ‘ethic’ subscale showed lowest correlation with the subscale ‘knowledge and skills’ among all individual competence subscales and relatively high correlations with ‘teamwork’ and ‘followship’ subscales among organizational competences. These suggest that the attitude of respecting survivors’ human rights and providing ethically appropriate care for them in disaster situations is also associated with the capacity to respect colleagues with different backgrounds and cooperate well with them. The organization-level subscales showed relatively high intra-scale correlations. Among the organizational competence subscales, ‘teamwork’ demonstrated relatively high positive correlations not only with ‘network’ and ‘followship’ but also with the individual competence subscales. It suggests that individual and organizational competences are interdependent. A high correlation was also demonstrated between the subscales ‘knowledge and skills’ and ‘network’, which is presumably associated with the actual task performance and role assumption among DMH workforce members in disaster situations.

The PCS-DMHW scores were compared according to the length of career of the participants to verify criterion-related validity. While no significant career-dependent differences were shown in the perceived competences of ‘ethic’, ‘qualification’, ‘a sense of calling’, and ‘followship’, the higher career group (≥5 years after obtaining professional qualification) yielded significantly higher scores in the subscales of ‘perceived knowledge and skills’ and ‘network’ compared with the lower career or no career groups. Given that these two subscales are related to the main tasks and roles of the DMH workforce in disaster situations, it may be assumed that career level has influence on the perceived competence in the actual work-related factors, not in the attitude factor of the DMH workforce members. The higher career level group (≥ 5 years) scored higher in ‘teamwork’ competence as well compared with the lower career level group (<5 years). These results partially support the validity of the PCS-DMHW.

Under the examination as presented above, the PCS-DMHW is successfully measuring perceived individual and organizational competences in the field of DMH. It has demonstrated relatively high reliability and validity. Although the sample utilized in this study is not from a normative dataset of mental health workers in Korea, it seems useful as an indicator of the need for improvement training in DMH competences based upon a standard score (e.g., T-score) drawn from mean and standard deviation of our participants. It should be cautiously suggested that training of the competences for disaster response is needed if the individual competence is less than 31 points or the organizational competence is less than 40 points (35 T-score).

In terms of scale development and construct, however, this instrument has several limitations. First, although the items of the PCS-DMHW, were generated after a thorough investigation through literature review and expert FGI, DMH being an emerging field with a relatively short history, no theoretical and empirical consensus has yet been reached among experts and professionals as to its core competences. Moreover, while there has been relatively extensive research on multidisciplinary teamwork in the medical field, teamwork has attracted little attention in the psychology field except in the subfield of organizational psychology. Therefore, continuous efforts will have to be undertaken to bring about theoretical and conceptual consensus on the core competences required of mental health workers for disaster response respond.

Second, Costello and Osborne [33] argue that a stable factor structure can be established only if at least four items are included in one factor. However, according to MacCallum et al. [34], at least three items are necessary to construct a factor properly. Relying on this, the PCS-DMHW was constructed with three items per factor in the preliminary research of this study lest the number of items should exceed the range of smooth survey administration by including four or more items in a factor.

Third, considering that the minimum number of samples is 50 and that the number of samples should be four- to fivefold the number of variables to be tested as prior conditions generally required for factor analysis, the minimum necessary number of samples for a disaster response core competence scale would be 180-225 (45 items×4-5). Based on this calculation, the number of samples for EFA and CFA was set at around 250 each. However, in the case of CFA, a minimum of 300 participants have been recommended [35]. Therefore, it is considered necessary to establish a more robust factor structure by conducting a CFA of the proposed scale on a larger number of mental health professionals.

Fourth, the PCS-DMHW does not directly measure the knowledge and skills actually required at disaster sites and the ability to work with colleagues. However, it may be considered a useful scale in terms of benefit-cost ratio, given the positive relationship between perceived competence and actual response capacity [18,19]. In order to help develop and strengthen more efficiently the competences of DMH workforce members, there is a need to assess their competences using various methods in addition to a self-reported scale.

Finally, the PCS-DMHW was developed and validated for Korean mental health workers. Korea has a short history of systematic response to large-scale disasters, and there are a relatively small number of professionals with experience in disaster response. In this study, the respondents’ PCS-DMHW scores were compared after classifying them into three groups according to the length of time after obtaining professional qualifications (no career, <5 years, and ≥5 years). However, it is necessary to compare the PCS-DMHW scores among groups classified according to the degree of experience or actual ability in disaster response in future studies. Also, the discriminant and convergent validity will have to be tested through correlation analysis with other competence scales. The applicability of the PCS-DMHW in other cultures and languages will also have to be investigated.

Despite the above-described limitations, the PCS-DMHW is the only tool known to the researchers for measuring the perceived competences of professionals from various fields and lay health workers in the field of DMH, not limited to specific occupation groups. Furthermore, items of the PCS-DMHW were developed at both individual and organizational levels so that it may be used in various education and training settings. The PCS-DMHW is expected to serve as a useful tool in the education and training programs aiming at developing and strengthening the DMH workforce’s professional capacity.