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 (ß = 0.251, P < 0.001) and PSS-4 (ß = 0.247, P < 0.001). Psychological stress, DSS, and somatization were correlated to QoL, as assessed by the modified PSS-4 (ß = 0.173, P < 0.001) and the PSS-4 (ß = 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.

Developing the Patient Health Questionnaire-8 for a greater impact on the quality of life of patients with functional dyspepsia compared to Somatic Symptom Scale-8.

BACKGROUND: To develop the Patient Health Questionnaire-8 (PHQ-8) as a more reliable approach than the Somatic Symptom Scale-8 (SSS-8), evaluating somatization which might be a critical factor influencing the quality of life (QoL) in patients with functional dyspepsia (FD). Also, the effects of somatization on QoL of FD patients were assessed by these two approaches. METHODS: Herein, 612 FD patients completed a questionnaire involving 25 items. 8/25 items were selected to develop the PHQ-8 by four methods of discrete degree, correlation coefficient, factor analysis, and Cronbach's α coefficient. Reliability and validity of the PHQ-8 and the SSS-8 were compared by principal component and confirmatory factor analyses. The effects of somatization, depression, and anxiety on the Nepean Dyspepsia Index (NDI) for QoL were explored by Pearson's correlation coefficient and linear regression analysis. RESULTS: The Cronbach's α coefficient for the PHQ-8 and the SSS-8 was 0.601 and 0.553, respectively, and the cumulative contribution rate of three extracted factors for the developed PHQ-8 and SSS-8 was 55.103% and 51.666%, respectively. Somatization evaluated by the PHQ-8 (r = 0.309, P < 0.001) and the SSS-8 (r = 0.281, P < 0.001) was found to be correlated to NDI. The model used for the PHQ-8 showed that the values of goodness-of-fit index (GFI) and adjusted GFI (AGFI) were 0.984 and 0.967, respectively, which indicated that the model fitted well. Linear regression analysis unveiled that somatization (ß = 0.270, P < 0.001), anxiety (ß = 0.163, P < 0.001), and depression (ß = 0.136, P = 0.003) assessed by the PHQ-8 were correlated to NDI. In addition, somatization (ß = 0.250, P < 0.001), anxiety (ß = 0.156, P < 0.001), and depression (ß = 0.155, P = 0.001) evaluated by the SSS-8 were correlated to NDI. CONCLUSIONS: PHQ-8 showed a superior reliability and validity, and somatization assessed by the developed PHQ-8 showed a greater influence on the QoL of FD patients as compared to the SSS-8. Our findings suggested that the developed PHQ-8 may show improvement in a reliable assessment of the effects of somatization on FD patients in lieu of the SSS-8.