Analysis on mental state of CSSD staff
According to the survey results, the CPSS score of the CSSD staff was 19.21 ± 7.265, which was lower than that of the clinical nurses , but higher than that of community residents in China . The perceived stress is the psychological response of the individual after perceiving and evaluating threatening stimuli in the environment . The novel coronavirus chiefly transmits via respiratory droplets and close contact ; CSSD staff members were not in direct contact with the confirmed or suspected COVID-19 patients, therefore, CSSD staff had a lower perceived stress regarding the COVID-19 epidemic compared to clinical nurses. Due to the nature of work in the CSSD, the CSSD staff was at risk of being infected with the novel coronavirus through occupational exposure. Therefore, the CSSD staff had a higher perceived stress from the threat of the novel coronavirus compared to the community residents during the epidemic.
The survey results showed that the CD-RISC score of the CSSD staff was 64.26 ± 15.129, lower than the norm in China , meaning that the CSSD staff had less resilience. The survey results also showed that the optimism factor score was the lowest and the tenacity factor score was the highest. Because the novel coronavirus is transmitted quickly and widely, the number of confirmed and suspected cases increased continuously as it became an epidemic; the clinical workload and work pressure also increased , the CSSD staff had to handle a high workload while being at risk of infection from occupational exposure. During the early stages of the epidemic, protective articles were in shortage in China, particularly facial masks and protective gowns, thus the CSSD staff was unable to effectively cope with and adapt to the stress resulting from the emergent public health event. The CSSD staff with higher tenacity factor score had more control when facing stress and the emergent public health event, and were not easily influenced. Therefore, it is recommended that managers pay attention to the resilience level of the CSSD staff and provide them with specific mental support to improve their resilience and decrease the negative impact stemming from the epidemic.
According to the study results, the CSSD staff had a lower anxiety level. Their SAS score was 37.39 ± 8.458, lower than the threshold score of SAS, possibly because most of the participants were from Tertiary A hospitals and received strong support from the public and governments, along with protective measures, disease screening tools and treatment conditions. As a result, Tertiary A hospitals were able to meet employment demands. Also, most of the participants were of middle and upper level education backgrounds, they learned about the COVID-19 epidemic through proper channels and took effective measures to protect themselves.
Analysis on correlation between CD-RISC, CPSS and SAS scores of CSSD staff
The survey results showed that the CSSD staff’s CPSS score was positively correlated with their SAS score (r = 0 .66, P < 0.01). That is to say, the higher the perceived stress, the more prevalent the anxiety. The possible reason is that the perceived stress was expressed as the tension and vulnerability of an individual, and the individual experienced negative moods, feelings, etc. to varying degrees . As demonstrated by Rooij SRD, perceived stress increases to some extent when a person is in a state of depression or anxiety . The findings are echoed by Wiegner, who found that perceived stress is usually accompanied by increased depression and/or anxiety . The CSSD staff felt the negative pressure due to outbreak of coronavirus, and was prone to anxiety after working under such stressful conditions for extended periods of time. The CD-RISC score was negatively correlated with the CPSS score (r = -0.617, P < 0.01), and the CD-RISC score was also negatively correlated with the SAS score (r = -0.477, P < 0.01), which are basically consistent with the results of He, et al.  and Xie, et al. . The scores indicate that the higher the resilience level, the lower the perceived stress and anxiety level. Individuals with higher resilience usually adopt optimistic and active attitudes under stressful conditions; they also know how to use external resources to handle problems . During the epidemic, the higher the resilience, the higher the consciousness of self-protection. If the necessary protection measures are taken and the correct operation procedures are implemented, stress and anxiety can be relieved.
Analysis on influencing factors for CPSS, SAS and CD-RISC scores
As shown in this study, job position and age of the CSSD staff were two factors that had high influence on the CPSS score. The CPSS score of the CSSD nurses was 20.081 ± 7.008, significantly higher than the CPSS score (15.898 ± 7.009) of the CSSD logistic staff; and the SAS score of the CSSD nurses was 38.332 ± 8.652, higher than the SAS score (35.469 ± 7.307) of the CSSD logistic staff. Due to the simple staffing structure in the CSSD, i.e. only the nurses and logistic staff in the CSSD, the CSSD logistic staff was responsible for handling most of the devices which required more physical labors, while the CSSD nurses played the leading role and were chiefly responsible for guidance and supervision of sterile supply. The CSSD nurses played an important role in controlling hospital-acquired infection. During the epidemic, controlling the hospital-acquired infection was the top priority in combating the epidemic, so the CSSD nurses had a higher level of perceived stress and anxiety compared to the CSSD logistic staff. Moreover, the CPSS score of the CSSD nurses in the younger age groups was higher than that of the CSSD nurses in the older age groups. The CSSD nurses in the younger age groups had shorter service periods, insufficient work experience and less experiences regarding hindrances; they also lacked strategies to use in response to stressful conditions . Conversely, the CSSD nurses in the older age groups were very experienced in work and life, so these nurses could maintain a stable mood and had the necessary skills to respond to the emergent public health event.
The political status was a factor had the most influence on the CD-RISC score. The CD-RISC score of members of the Communist Party of China was 69.726 ± 12.071, higher than that of people without party affiliation (63.816 ± 15.664), and that of members of the Chinese Communist Youth League and probationary members of the Communist Party of China (59.039 ± 13.676). This is possibly because the members of the Communist Party of China always adhered to the mission of serving the public wholeheartedly, maintaining a spirit of contribution and perseverance.