Table 4.
Rasch analysis of the Sleep Preoccupation Scale (SPS) n = 523
| Item | Ability measure | SE | Infit | Outfit | Point biserial |
|---|---|---|---|---|---|
| SPS1 | -0.48 | 0.05 | 1.24 | 1.26 | 0.48 |
| SPS2 | -0.64 | 0.05 | 0.88 | 0.89 | 0.6 |
| SPS3 | -0.27 | 0.05 | 0.83 | 0.87 | 0.62 |
| SPS4 | -0.07 | 0.05 | 0.94 | 0.93 | 0.61 |
| SPS5 | -0.09 | 0.05 | 1.09 | 1.13 | 0.53 |
| SPS6 | -0.22 | 0.05 | 0.99 | 1.02 | 0.59 |
| SPS7 | -0.46 | 0.05 | 1.19 | 1.19 | 0.55 |
| SPS8 | 0.44 | 0.05 | 1.01 | 1.04 | 0.58 |
| SPS9 | -0.32 | 0.05 | 0.95 | 0.93 | 0.62 |
| SPS10 | 0.31 | 0.05 | 1.04 | 1.17 | 0.46 |
| SPS11 | 0.24 | 0.05 | 0.79 | 0.8 | 0.64 |
| SPS12 | 0.1 | 0.05 | 0.96 | 0.96 | 0.61 |
| SPS13 | -0.36 | 0.05 | 1.01 | 1.05 | 0.55 |
| SPS14 | -0.14 | 0.05 | 1.15 | 1.18 | 0.56 |
| SPS15 | -0.04 | 0.05 | 0.82 | 0.79 | 0.63 |
| SPS16 | 0.31 | 0.05 | 0.81 | 0.82 | 0.62 |
| SPS17 | 0.43 | 0.05 | 0.83 | 0.83 | 0.63 |
| SPS18 | 0.74 | 0.05 | 1 | 1.02 | 0.57 |
| SPS19 | -0.13 | 0.05 | 0.94 | 0.92 | 0.62 |
| SPS20 | 0.07 | 0.05 | 1.04 | 1.03 | 0.58 |
| SPS21 | 0.57 | 0.05 | 1.04 | 1.16 | 0.57 |
| SPS22 | 0.01 | 0.05 | 1.02 | 1 | 0.61 |
Note. Item analysis was performed using the Rating Scale Model (RSM). AIC = Akaike information criterion (28626.57), BIC = Bayesian information criterion (29029.02), CAIC = consistent Akaike information criterion (29124.02). The log-likelihood represents the log-likelihood value of the model (-14218.28). SSD = squared standard deviation (0.71) and MSE = mean squared error (0.06)