Table 2.
Psychometric properties of the Gaming Disorder Test (GDT) at the item level
| Item # | Classical test theory analyses | Rasch analyses | ||||||
|---|---|---|---|---|---|---|---|---|
| Factor loadinga | Item-total correlation | Infit MnSq | Outfit MnSq | Discrimination | Difficulty | DIF contrasts across sexescd | DIF contrasts across gaming-time groupsce | |
| GDT-1 | 0.684 | 0.507 | 0.96 | 0.96 | 0.99 | -0.27 | -0.03 | -0.04 |
| GDT-2 | 0.713 | 0.557 | 0.92 | 0.90 | 1.07 | 0.34 | 0.21 | 0.19 |
| GDT-3 | 0.709 | 0.499 | 1.05 | 1.03 | 0.94 | -0.23 | 0.10 | -0.21 |
| GDT-4 | 0.749 | 0.533 | 1.06 | 1.00 | 1.01 | 0.16 | -0.20 | 0.10 |
a Based on confirmatory factor analysis
b Using Pearson correlation
c DIF = differential item functioning; DIF contrast > 0.5 indicates substantial DIF
d DIF contrast across sexes = Difficulty for females-Difficulty for males
e DIF contrast across time on gaming = Difficulty for participants with median weekly hours or below spent gaming (i.e., < 19.5 h)-Difficulty for participants with above median weekly hours spent gaming (i.e., ≥ 19.5 h)
MnSq = mean square error; DIF = differential item functioning