Table 2 Descriptive statistics for 5,140 participants on the GAD-2 and PHQ-2 items of the PHQ-4, and interitem correlations (covariances) and reliability
Item | n | Mean | SD | Skewness | Kurtosis | Item-rest or corrected item-total Correlation | Cronbach’s α | Composite reliability |
|---|---|---|---|---|---|---|---|---|
GAD-2 items (n = 5,140) |  |  |  |  |  |  |  |  |
Item1: Nervousness | 5,140 | 0.85 | 1.03 | 0.94 | 2.63 | 0.83 | Â | Â |
Item 2: Worries | 5,140 | 0.82 | 1.04 | 0.99 | 2.67 | 0.83 | Â | Â |
GAD-2 scale | Â | 1.67 | 1.97 | 0.96 | 2.70 | Â | 0.90 | 0.90 |
PHQ-2 items (n = 5,140) |  |  |  |  |  |  |  |  |
Item 3: Loss of interest | 5,140 | 0.80 | 1.01 | 1.00 | 2.75 | 0.76 | Â | Â |
Item 4: Depressive mood | 5,140 | 0.80 | 1.01 | 1.02 | 2.81 | 0.84 | Â | Â |
PHQ-2 scale | Â | 1.60 | 1.89 | 0.98 | 2.83 | Â | 0.86 | 0.86 |
Total scale score: PHQ-4 (n = 5,140) |  | 3.28 | 3.67 | 0.95 | 2.78 |  | 0.92 | 0.92 |