Developing the modified 4-item version of perceived stress scale for functional dyspepsia.

Background: To develop the modified 4-item version of Perceived Stress Scale (PSS) with a better reliability and validity than the 4-item version of PSS (PSS-4) in evaluating psychological stress in patients with functional dyspepsia (FD). The present study also aimed to explore the correlation between dyspepsia symptoms severity (DSS), anxiety, depression, somatization, quality of life (QoL), and psychological stress assessed by two approaches in FD.

Methods: A total of 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, such as Cronbach's coefficient, exploratory factor analysis (EFA), correlation coefficient, discrete degree, and item analysis, to develop the modified PSS-4. The reliability and validity of the modified PSS-4 and the PSS-4 were compared by internal consistency, EFA, and confirmatory factor analysis (CFA). The correlation between psychological stress assessed by two approaches and DSS, anxiety, depression, somatization, and QoL was explored by Pearson's correlation coefficient and multiple linear regression analysis.

Results: Cronbach's α coefficient of the modified PSS-4 and the PSS-4 was 0.855 and 0.848, respectively, and a common factor was extracted. 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-fit index (GFI) and the adjusted GFI (AGFI) were 0.987 and 0.933, respectively, indicating that the model fitted well. Psychological stress was correlated to DSS, anxiety, depression, somatization, and QoL as assessed by the modified PSS-4 and PSS-4. Multiple linear regression analysis revealed that psychological stress was correlated to somatization, as assessed by the modified PSS-4 (β = 0.251, P < 0.001) and PSS-4 (β = 0.247, P < 0.001). Psychological stress, DSS, and somatization were correlated to QoL, as assessed by the modified PSS-4 (β = 0.173, P < 0.001) and the PSS-4 (β = 0.167, P < 0.001).

Conclusions: The modified PSS-4 showed better reliability and validity, and psychological stress had a greater effect on the somatization and QoL of FD patients assessed by the modified PSS-4 than PSS-4. These findings were helpful for further investigation of the clinical application of the modified PSS-4 in FD.