Table 4.
DIF across countries prior to and after applying the post-hoc strategies (n = 243)
| Items | Prior modification | After modification | ||||||
|---|---|---|---|---|---|---|---|---|
| MS | F | df | p | MS | F | df | p | |
| SWLS | Strategy 2 | |||||||
| Ideal life | 1.72 | 3.36 | 5 | 0.006 | 0.86 | 1.47 | 5 | 0.202 |
| Life conditions | 1.54 | 2.74 | 5 | 0.020 | 0.58 | 0.88 | 5 | 0.494 |
| Life satisfaction | 1.64 | 2.70 | 5 | 0.022 | 1.55 | 2.26 | 5 | 0.050 |
| Got things I want | 3.03 | 4.01 | 5 | 0.002b | deleted | |||
| Change nothing in life | 15.15 | 11.20 | 5 | 0.000b | deleted | |||
| LISAT-9 | Strategy 4 | |||||||
| Life as a whole | 1.45 | 2.35 | 5 | 0.042 | 0.76 | 1.15 | 5 | 0.333 |
| Self care | 3.23 | 3.64 | 5 | 0.004b | 2.43 | 2.85 | 5 | 0.016 |
| Vocational situation | 1.34 | 1.67 | 5 | 0.142 | 0.97 | 1.37 | 5 | 0.237 |
| Financial situation | 7.13 | 8.08 | 5 | 0.000b | merged | |||
| Leisure situation | 4.17 | 6.64 | 5 | 0.000b | merged | |||
| Sexual life | 0.87 | 1.04 | 5 | 0.3959 | 2.01 | 1.90 | 5 | 0.095 |
| Partner relations | 2.27 | 1.65 | 5 | 0.1513 | deleted | |||
| Family life | 3.74 | 3.38 | 5 | 0.0058 | deleted | |||
| Contact with friends | 0.72 | 0.80 | 5 | 0.5485 | 2.21 | 2.05 | 5 | 0.073 |
| Merged item 4 and 5 | 1.19 | 1.90 | 5 | 0.095 | ||||
| PWI | Strategy 3 | |||||||
| Whole life | 1.80 | 2.59 | 5 | 0.027 | 1.783 | 2.53 | 5 | 0.030 |
| Living standard | 2.08 | 2.28 | 5 | 0.048 | 2.094 | 2.25 | 5 | 0.051 |
| Health | 9.22 | 9.59 | 5 | 0.000b | merged | |||
| Life achievement | 1.72 | 1.80 | 5 | 0.114 | 1.792 | 1.84 | 5 | 0.106 |
| Relationships | 4.44 | 4.65 | 5 | 0.001b | merged | |||
| Feeling safe | 3.80 | 5.63 | 5 | 0.000b | merged | |||
| Feel part of community | 1.82 | 2.20 | 5 | 0.055 | 1.811 | 2.16 | 5 | 0.060 |
| Future security | 2.77 | 3.88 | 5 | 0.002b | merged | |||
| Merged item 3 and 8 | 6.683 | 9.05 | 5 | 0.000b | ||||
| Merged item 5 and 6 | 0.286 | 0.39 | 5 | 0.858 | ||||
| WHOQoL-5 | Strategy 3 | |||||||
| Health | 2.90 | 3.85 | 5 | 0.002b | merged | |||
| Activities of daily living | 1.50 | 2.04 | 5 | 0.075 | 1.41 | 2.04 | 5 | 0.074 |
| Relationships | 2.32 | 2.50 | 5 | 0.031 | 2.14 | 2.46 | 5 | 0.034 |
| Living place | 2.97 | 2.99 | 5 | 0.012 | 2.69 | 2.89 | 5 | 0.015 |
| Quality of life | 2.36 | 4.13 | 5 | 0.001b | merged | |||
| Merged item 1 and 5 | 0.80 | 1.47 | 5 | 0.200 | ||||
Index:
b: Below the Bonferroni corrected probability level of p < 0.05/number of items (SWLS and PWI: p < 0.01; LISAT and PWI: p < 0.006)
Abbreviations:
SWLS: Satisfaction with life scale; LISAT: Life satisfaction questionnaire; PWI: Personal well-being index; WHOQoL: World Health Organization quality of life assessment; DIF: Differential item functioning; MS: Mean square sum of residuals; F: F-distributed test value; df: Degrees of freedom; p: probability