Developing the modified 4-item version of the Perceived Stress Scale with a better reliability and validity in functional dyspepsia

Abstract

Abstract Background: To develop the modified 4-itemversion of the Perceived Stress Scale (PSS) as a better reliability and validity than the 4-item version of the PSS (PSS-4) in evaluating psychological stress in patients with functional dyspepsia (FD). Also, to explore the relationship between psychological stress assessed by two approaches and symptoms of FD. Methods: 389 FD patients who met the Roman IV criteria completed the 10-item version of the PSS (PSS-10) and 4/10 items were selected by five methods of Cronbach’s coefficient, exploratory factor analysis (EFA), correlation coefficient, discrete degree and item analysis to develop the modified PSS-4. Reliability and validity of the modified PSS-4 and the PSS-4 were compared by internal consistency, EFA and confirmatory factor analysis (CFA). The relationship between psychological stress assessed by two approaches and symptoms of FD were explored by Pearson’s correlation coefficient and multiple linear regression analysis. Results: The Cronbach’s α coeffcient of the modified PSS-4 and the PSS-4 was 0.855 and 0.848, respectively, and a common factor was extracted, respectively. The cumulative contribution rate of one factor to the overall variance for the modified PSS-4 and the PSS-4 was 70.194% and 68.698%, respectively. The model used for the modified PSS-4 showed that the values of the goodness of ft index (GFI) and the adjusted GFI (AGFI) were 0.987 and 0.933, respectively, which indicated that the model fitted well. Psychological stress assessed by the modified PSS-4 (r=0.302, P=0.000) and the PSS-4 (r=0.301, P=0.000) was found to be correlated to somatization. And psychological stress assessed by the modified PSS-4 (r=0.225, P=0.000) and the PSS-4 (r=0.220, P=0.002) was found to be correlated to quality of life (QoL). Multiple linear regression analysis unveiled that psychological stress (β=0.251, P=0.000), dyspepsia symptoms severity (DSS) (β=0.345, P=0.000) assessed by the modified PSS-4 were correlated to somatization. In addition, psychological stress (β=0.247, P=0.003), DSS (β=0.343, P=0.000) assessed by the PSS-4 were correlated to somatization. Psychological stress (β=0.173, P=0.000), DSS (β=0.283,P=0.000), somatization (β=0.216, P=0.000) assessed by the modified PSS-4 were correlated to QoL. In addition, psychological stress (β=0.167, P=0.000), DSS (β=0.281, P=0.000), somatization (β=0.219, P=0.000) assessed by the PSS-4 were correlated to QoL. Conclusions: The modified PSS-4 showed a better reliability and validity, and psychological stress assessed by the modified PSS-4 may has a greater effect on the somatization and QoL of FD patients as compared to the PSS-4. These findings were helpful for further research on the clinical application value of the modified PSS-4 in FD.