Cross-sectional online self-report survey was conducted in 9 tertiary hospitals in Sichuan province in China. The questionnaire was built on a professional questionnaire survey network platform called “Wenjuan Xing” (www.wjx.cn) and then was shared on social media (WeChat). The online questionnaire had three sections: informed consent, general information questionnaire, and the Chinese version of the PCS-DMHW scale were required. After a brief written informed consent at the beginning of the survey, the questionnaire was answered and it took 10 to 15 minutes for the participants to complete the survey.

In investigation research, the minimum sample size was 5-10 times the number of items on the scale [18], and there were 48 items in PCS-DMHW. According to 10 times the number of items, 480 samples were needed. Taking into account the 20% invalid questionnaire, the number of sample cases was finally determined to be 576. Using convenience sampling method, we contacted department heads in each hospital and invited them to forward our questionnaire to their WeChat group of staff to recruit participants. 733 mental health workers from 9 tertiary hospitals in Sichuan province were investigated from March 24, 2020 to April 14, 2020, among them, 715 participants completed the anonymous online survey and 18 participants completed the offline survey. Inclusion criteria: participants were aged over 18 years; worked in mental health related units; obtained informed consent and volunteered for the study. Exclusion criteria: mental and psychological health-related interns. Since the questionnaire was mainly collected online, the response rate cannot be calculated. And a total of 706 questionnaires were analyzed excluding 27 questionnaires which included unanswered items or founded it unreliable.

This survey adopted an online survey method. The researcher introduced the research purpose, significance and precautions for filling out the questionnaire to the survey participants through the “Wenjuan Xing,” and conducted the survey after obtaining the informed consent of the survey participants. After the survey was completed, a sample of 50 participants was randomly selected and repeated measurement was performed two weeks later to evaluate the scale’s retest reliability.

Excel was used for data entry and SPSS 21.0 (IBM Corp., Armonk, NY, USA) software was used for data statistics. The internal consistency reliability of Cronbach’s α coefficient rating scale and the retest reliability of Pearson correlation coefficient r rating scale with two test scores were used. The content validity index (CVI) was used to evaluate the content validity of the scale, and the content of the item was evaluated by six experts. A 4-level scoring method was adopted, with 1 being “irrelevant,” 2 being “weakly correlated,” 3 being “moderately correlated,” and 4 being “strongly correlated.” The CVI of the scale was calculated according to the expert evaluation results. Exploratory factor analysis (EFA) was used to evaluate the structural validity of the scale. To test the measurement model of the PCS-DMHW scale and to ensure its construct validity, we first computed the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy and Bartlett test of sphericity (BTS) to determine whether our data were suitable for EFA. The KMO index ranges between 0 and 1, and values above 0.5 are considered suitable for factor analysis. To ensure the suitability of factor analysis, BTS should be statistically significant (p≤0.05), which indicates that sufficient correlations exist among the variables. EFA was conducted to determine which of the scale’s items should be retained. Factors were extracted using principal axis factoring, which uses estimates of communalities on the diagonal in the extraction process, and direct oblimin rotation was used under the assumption of intercorrelations among factors. The common factors representing the scale structure were extracted to obtain the cumulative variance contribution rate of the common factors. The common factors could explain more than 40% of the variation, and the load value of each item in the corresponding factors was high (≥0.4), which was a relatively ideal factor analysis result. p<0.05 was regarded as the statistically significant difference.

Among the 706 participants, 103 were males (14.6%) and 603 were females (85.4%). Age was 20 to 57 years old. The basic information of mental health workforce was as follows, see Table 1.

Disaster refers to a crisis event characterized by chaos, suddenness and large-scale trauma, including natural disasters and man-made disasters [19]. China is one of the countries with the most serious natural disasters in the world [20]. In order to better deal with and prevent disasters, the core capabilities of disasters have gradually attracted the attention of scholars [21]. Among them, disaster-related mental health, especially post-traumatic stress disorder and depression have become areas of great concern to the academic community [22,23]. Although disaster medicine in our country has developed rapidly in recent years, it still inevitably suffers from the problems of weak foundation, insufficient attention and insufficient teaching of basic education medicine, the disaster medicine specialized reserve talented person is relatively short [24]. Moreover, in the hospital clinic, most of the medical staff obtain the relevant disaster psychological rescue knowledge through self-study and experience accumulation, and the correctness and pertinence of the knowledge are deficient, it may affect the specialization and comprehensiveness of psychological intervention in disaster rescue [25]. A survey was conducted among medical personnel who had participated in disaster rescue (earthquake, traffic accident, fire, etc.) in four hospitals in Shanghai and Sichuan from October 2013 to January 2014 by using the method of objective sampling, it was found that only 63 (25.5%) of the 247 medical personnel had participated in relevant psychological training, and the mental knowledge of disaster rescue was seriously insufficient [25]. There was another study showed that disaster psychological assistance workers need to receive long-term and systematic training to improve their professional knowledge and skills to ensure their competency [26]. Therefore, how to improve the ability of mental health workers to cope with disasters has gradually become one of the future research directions of the psychology department. But in China, it does not have a good assessment tool to measure the capacity of mental health workers in disasters. So it is of great significance to introduce the English version of the PCS-DMHW into China. First, point out the direction for setting the objectives and contents of psychological rescue courses related to disaster medicine undergraduate or graduate education. It is not only necessary to set up courses to improve personal professional psychological knowledge and skills, but also relevant courses to cultivate team communication, collaboration, resource allocation, and organizational leadership. Second, the Chinese version of the PCS-DMHW scale can be used as an evaluation tool for the effect evaluation of disaster psychological rescue continuing education training project, to evaluate whether the students have mastered relevant professional knowledge and skills, and whether they can complete the team psychological rescue work well. Third, as one of the evaluation criteria for the emergency dispatch of psychological rescuers in sudden disaster events, it evaluates whether the tested person is competent for the psychological rescue work of disaster, so as to ensure the professional psychological rescue ability of the rescue team to the greatest extent.

Reliability is mainly used to examine the internal consistency, accuracy and stability of the scale. The higher the reliability coefficient, the small the variation degree caused by random errors in the measurement process. This study used internal consensus reliability and test-retest reliability to evaluate the reliability of the Chinese version of the PCS-DMHW scale. The internal consensus reliability results showed that the Cronbach’s α coefficient of the Chinese version of the PCS-DMHW scale was 0.978, and the Cronbach’s α coefficients of the individual competences and organizational competences subscale was 0.956 and 0.964, respectively, and the Cronbach’s α coefficients of each field of the scale ranged from 0.863 to 0.928, indicating that the scale had good homogeneity. The test-retest reliability results showed that the Chinese version of PCS-DMHW was 0.949, and the scores of the individual competences and organizational competences subscales was 0.932 and 0.927, respectively, indicating that the scale had better cross-time stability.

Validity refers to the extent to which a research tool truly reflects the concept it is intended to study. The higher the degree of reflecting the research concept, the more accurate and valid the measurement results will be. This study evaluated content validity and construct validity. The results showed that the Chinese version of the PCS-DMHW total table was 0.833-1.000, the S-CVI/UA was 0.833, and the S-CVI/Ave was 0.972, the individual and organizational competences subscale I-CVI was 0.833-1.000, S-CVI/UA was 0.875, 0.857, and S-CVI/Ave was 0.979, 0.976, respectively, which showed that the PCS-DMHW project in China was representative and could reflect the disaster capacity of mental health workers. EFA showed that two common factors were extracted from individual and organizational competences subscale, the cumulative variance contribution rate were 61.91% and 68.21%, respectively, and the factor load value were all greater than 0.40, suggesting that the extracted common factors had strong explanatory power and good construct validity. Among them, Item 7 and Item 11 in organizational competences subscale had double-load phenomenon, which indicated that item differentiation should be improved. Although these two entries should have been removed from a statistical point of view, it was decided to keep them and that they belonged to the original dimension respectively. Common factor 1 in the individual competences subscale contains 18 items, which is named “professional quality” in this study, and are specifically divided into three dimensions: professional knowledge, professional skills, and professional qualifications (items 5, 9, 11), in which professional knowledge covers two aspects, including understanding disaster (items 17, 19, 24) and tailored support (items 8, 12, 15), and professional skills cover three aspects, including problem-solving (items 3, 7, 13), communication (items 2, 6, 18), and information sharing (items 1, 10, 14). Common factor 2 in the individual ability scale contains 6 items, which is named “professional attitude” in this study, including two dimensions: calling (items 20, 21, 22) and ethic (items 4, 16, 23). The common factor 1 in the organizational competences subscale is named “management,” which specifically includes network, conflict management (items 5, 14, 15) and leadership management (items 16, 20, 21). The network includes two aspects, namely disaster management (items 10, 12, 13) and linking local resources (items 2, 7, 18). The common factor 2 in the organizational competences subscale is named “team,” which specifically includes cooperation (items 9, 17, 19), communication (items 6, 8, 11), and followship (items 1, 3, 4).

Compared with the original scale, the Chinese version of PCS-DMHW also has good internal consistency reliability and construct validity in mental health workforce. However, there are two major differences in research results. First, the test-retest reliability coefficient for 2-week interval of the Chinese version of individual ability and organizational competences subscale was both 0.9 above. But the test-retest reliability coefficient for 2-week interval of the Korean version of individual competences and organizational ability subscale was only 0.637 and 0.624, respectively. It can be seen that the test-retest reliability of the Chinese version PCS-DMHW scale in this study is relatively high, and shows good stability and consistency across time in this measurement. Second, we found that the common factors extracted by the team of Yoon and Choi was not completely consistent with the theoretical structure when testing the validity of the English PCS-DMHW scale. The Chinese version of the PCS-DMHW scale was different from the original scale in terms of the number of common factors and items. It may be that the team of Yoon and Choi designed the dimensions and items of the PCS-DMHW scale mainly based on some theoretical ideas, and conducted an exploration analysis to analyze the scale structure from the perspective of statistics. To extract common factors, common factors may be different according to different research objects and sample sizes.

The limitations of this study were: 1) The source of the sample was relatively limited: the sample size of this study was relatively sufficient, but the survey population is mainly concentrated in Sichuan, which has certain regional limitations; 2) The survey method was relatively simple: since the survey time was during the COVID-19 epidemic, it was not suitable to face-to-face gathering of the crowd to carry on the investigation, therefore this research adopted the network investigation method, although this method was not limited by time and space, it was more convenient and fast, but it could not completely guarantee the reliability of the survey results and the accuracy of the samples; and 3) The empirical validity needs to be improved: the limitation of this study was that the scale after the Chinese version only proposed the number of common factors and the items covered, but did not propose clear dimensions. Subsequent research will further explore and verify its structural validity. In addition, this study was the first time to introduce the PCS-DMHW scale in China, and there was a lack of disaster competency related scale for mental health workforce in China. It was suggested that face-to-face investigation should be adopted in future research.

In conclusion, the Chinese version of the PCS-DMHW scale had good reliability and validity, with a concise scale structure, simple testing and scoring methods, and was suitable for evaluating the disaster core competence of mental health workforce in China in the context of Chinese culture. The research could be combined with multiple centers to expand its scale, as well as the sampling breadth and hospital level, and further verify the validity and reliability of the scale through clinical practice.