To the authors' knowledge, this is the first study designed to evaluate the reliability and validity of the Simplified Chinese version of the PSS-10 scale. Overall, the psychometric data presented in this study support the conclusion that the Simplified Chinese version of the PSS-10 (C-PSS-10) has adequate psychometric properties.
The overall Cronbach's alpha of the Simplified Chinese version of PSS-10 was 0.86 in this sample. This value is in accord with findings from other studies of different language versions, where reliability coefficients ranged from 0.78–0.91 
. The two-week test-retest reliability of C-PSS-10 was 0.68, which is acceptable when compared with the original findings that the test-retest reliability was 0.85 in the college sample after 2 days and 0.55 in the community sample after 6 weeks 
Previous studies have shown that the PSS-10 has concurrent validity with a number of other measures including the State Trait Anxiety Inventory (STAI) and the Beck Depression Inventory (BDI) 
. In the current study, the Simplified Chinese version of PSS-10 was also found to be significantly and moderately positively correlated with measures of anxiety and depression (r
0.58 for BAI and 0.67 for BDI; p<0.001), and thus the construct validity of this scale was confirmed. These results also indicate that psychological stress is associated with mental health issues.
With regard to the PSS-10′s factor structure, researchers have found that it has 2 related latent factors 
, representing positive and negative feelings. In the present study, the EFA yielded the same result as those found in other language versions 
. In Cohen's original analysis, two factors yielded eigenvalues of 3.4 and 1.4, which accounted for 48.9% and 14.5% of the variance respectively 
. In the present study, the Simplified Chinese version of the PSS-10 yielded eigenvalues of 4.76 and 1.48, and accounted for 47.61% and 14.80% of the variance respectively. Concerning item loadings, item 8 had high loadings (>0.3) on the other factors in the present study. Similar results have been reported in other studies 
. The CFA demonstrated a relatively better goodness-of-fit for the two-factor solution model for the Simplified Chinese version compared to the original version, which found that the PSS-10 revealed an adequate two-factor solution: goodness of fit index
0.926, Root Mean Square Residual
0.039, Comparative Fit Index
. Although we confirmed the two-factor model of PSS-10, we do not recommend using two separate sub-scales clinically. The PSS-10′s authors suggested that any distinction between these factors is irrelevant 
, and another study also suggested to use the full scale as a whole to evaluate perceived stress level 
There are several limitations to this study that should be noted. First, police have a very special occupation, which is full of stressful events in daily work. We can see this stress in our data because the sample's average score on the C-PSS-10 was relatively high compared to the community residents used in the original norms 
. Additionally, we recruited only female police officers in this study, and all the participants were relatively young. Thus, the characteristics of this sample may limit its generalizability of the results to other populations. However, it is worth noting that according to studies of the English version, the PSS is not a specific-population- dependent instrument. Similar psychometric properties have been found across a variety of different sub-populations in different locations 
. The Traditional Chinese version of PSS has also been found to have similar psychometric properties in two different sub-groups in Hong Kong 
. Therefore, on the basis of these findings we expect that the Simplified Chinese version could be validly used in a broader range of Chinese-speaking populations as well. Second, because of the cross-sectional nature of this study, the predictive validity of this scale could not be confirmed. Third, this study was not able to evaluate the discriminant validity of the C-PSS-10 and further study in that area is needed. Fourth, like other studies using similar methodologies 
, we were unable to determine the extent to which our concurrent validity findings represent an overlap between the constructs of stress, depression, and anxiety such that the PSS could be considered to be a “proxy measure” for depression or anxiety. Fifth, it was outside the scope of our study to determine whether additional items might be necessary to capture additional culturally-relevant aspects of reactions to stress. Future studies might examine each of these issues.
In conclusion, the results of this study suggest that the Simplified Chinese version of the PSS-10 is an instrument with adequate psychometric properties. Therefore, the Simplified Chinese version of PSS-10 can be a very useful instrument to measure psychological stress among Chinese-speaking populations in China and elsewhere in the world.