Table 3 Rasch analysis results of the ZBI
ZBI-22 | ZBI-12 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
No. | Measure | INFIT MNSQ | OUTFIT MNSQ | Disordered category or threshold | No. | Measure | INFIT MNSQ | OUTFIT MNSQ | Disordered category or threshold |
1. Asks for more help than needs | 0.44 | 1.321 | 1.453 | Yes | No | ||||
2. Not have enough time | 0.04 | 0.912 | 0.859 | No | 1 | − 0.19 | 0.903 | 0.897 | No |
3. Feel stressed | − 0.03 | 0.697 | 0.614 | Yes | 2 | − 0.65 | 0.905 | 0.865 | No |
4. Feel embarrassed | 0.14 | 1.120 | 1.099 | Yes | |||||
5. Feel angry | 0.13 | 0.891 | 0.932 | No | 3 | 0.40 | 0.978 | 1.014 | No |
6. Negative relationships | 0.37 | 0.941 | 0.956 | Yes | 4 | 0.67 | 1.129 | 0.855 | Yes |
7. Afraid about the future | − 0.64 | 1.082 | 1.134 | No | |||||
8. Dependent on you | − 0.92 | 1.258 | 1.334 | Yes | |||||
9. Feel strained | 0.23 | 0.760 | 0.655 | No | 5 | 0.33 | 0.818 | 0.781 | Yes |
10. Health decreased | 0.31 | 0.646 | 0.795 | No | 6 | 0.40 | 0.806 | 1.083 | No |
11. Lack of privacy | − 0.04 | 0.616 | 0.730 | No | 7 | 0.11 | 0.893 | 1.062 | No |
12. Lack of social life | 0.19 | 0.675 | 0.639 | No | 8 | 0.32 | 0.701 | 0.682 | No |
13. Feel uncomfortable | 0.38 | 0.943 | 1.967 | No | |||||
14. Expecting to be cared for | − 0.58 | 1.512 | 1.612 | Yes | |||||
15. Lack of money | 0.12 | 1.355 | 1.399 | No | |||||
16. Unable to care much longer | 0.72 | 0.789 | 0.777 | Yes | |||||
17. Lost control of life | 0.60 | 0.844 | 0.737 | Yes | 9 | 0.35 | 0.918 | 0.796 | Yes |
18. Leave the care | 0.40 | 1.423 | 1.358 | Yes | |||||
19. Uncertain about what to do | 0.14 | 0.795 | 0.704 | Yes | 10 | 0.40 | 1.035 | 1.029 | Yes |
20. Should do more | − 0.71 | 1.264 | 1.256 | No | 11 | − 1.08 | 1.406 | 1.339 | No |
21. Could do a better job caring | − 0.80 | 1.383 | 1.367 | No | 12 | − 1.06 | 1.449 | 1.317 | No |
22. Overall feeling of burden | − 0.50 | 0.912 | 0.973 | Yes | |||||
PCA | ZBI-22 | ZBI-12 |
|---|---|---|
%Variance explained by measures | 46.0% | 48.7% |
Unexplained variance in first contrast | 2.52 (6.2%) | 3.03 (12.6%) |
Disattenuated correlation | 0.896–1.000 | 0.357–1.000 |
Pair of item that standardized residual correlation > 0.2 | #20(should do more)—#21(could do a better job) #11(lack of privacy)—#12(lack of social life) #1(asks for more help than needs)—#18(leave the care) #15(lack of money)—#16(unable to care much longer) #5(feel angry)—#9(feel strained) | #11(should do more)—#12(could do a better job) #3(feel angry)—#5(feel strained) #8(lack of privacy)—#9(lack of social life) |
Item separation/reliability | 2.57/0.87 | 2.03/0.80 |
Person separation/reliability | 4.08/0.94 | 3.97/0.94 |