Abstract
BackgroundDuring the epidemic of COVID-19 of China, the emergency medical teams are facing serious stress in the front-line. As far as we know, there are no studies to test the applicability and measurement properties of the 10-item Chinese perceived stress scale (CPSS-10) in the emergency medical team.MethodsFrom March 17 to 27, 2020, an online survey was conducted on the emergency medical teams of Liaoning Province who supporting Wuhan. The CPSS-10 was used to measure the stress of medical workers. Classical test theory (CTT), bifactor model and multidimensional graded response model (MGRM) were used to analyze the measurement characteristics and differential item functioning (DIF) of CPSS-10.ResultsThe Cronbach's alpha coefficient of CPSS-10 was 0.86. Bifactor model confirmed that CPSS-10 was a two-factor structure. MGRM showed ordered response categories of K10. Item 8 could distinguish individual stress, but the slope of this item was very large (slope is 7.97, which was higher than 4), showing local dependence. There was a significant age DIF, but no DIF in gender. After removing the items 2, 5, and 8, the CPSS-7 showed high reliability, without DIF of age and gender, and there was no local dependence.ConclusionsMGRM could provide useful measurement information about CPSS-10 and CPSS-7. MGRM found that CPSS-10 did not fully conform to the item response theory (IRT). CPSS-7 had proved to be a more effective and reliable tool for assessing the perceived stress of emergency medical team.