Table 4.
Performance of the preliminary Rasch analysis of the WHOQOL-BREF domains (sub-sample (for validation) size, n = 300)
| WHOQOL-BREF scales | Original instrument | Summary of overall model fit statistics of each domain (original instrument) | |||||
|---|---|---|---|---|---|---|---|
| Location | S. E. | Residual | χ2 | p-value | |||
| Overall | |||||||
| Overall QOL | −0.04 | 0.12 | −1.29 | 2.5 | 0.645 | ||
| General Health | 0.04 | 0.12 | − 1.3 | 4.41 | 0.353 | ||
| Physical domain | |||||||
| Pain (3) | −1.40 | 0.10 | −0.23 | 15.22 | 0.004 | Person separation index | 0.834 |
| Dependence on medical aids (4) | −1.98 | 0.10 | 1.91 | 18.41 | 0.001 | Coefficient alpha | 0.852 |
| Energy (10) | 1.24 | 0.09 | 1.91 | 8.50 | 0.075 | Chi-square (Degrees of freedom) | 107.18 (28) |
| Mobility (15) | 0.19 | 0.09 | −1.43 | 16.49 | 0.002 | p-value | 0.0000 |
| Sleep and rest (16) | −0.28 | 0.09 | 1.80 | 24.03 | 0.007 | Items fit residual (mean (SD)) | −0.34 (2.39) |
| Activities of daily living (17) | 1.63 | 0.10 | −2.16 | 14.45 | 0.006 | Persons fit residual (mean (SD)) | −0.48 (1.17) |
| Work capacity (18) | 0.61 | 0.10 | −4.20 | 20.08 | 0.000 | ||
| Psychological domain | |||||||
| Positive feeling (5) | 0.23 | 0.09 | −2.41 | 25.26 | 0.000 | Person separation index | 0.767 |
| Personal belief (6) | 0.55 | 0.08 | −0.97 | 34.83 | 0.000 | Coefficient alpha | 0.776 |
| Concentration (7) | −0.69 | 0.09 | −2.31 | 13.77 | 0.008 | Chi-square (Degrees of freedom) | 130.64 (24) |
| Bodily image (11) | 0.20 | 0.10 | 1.56 | 18.82 | 0.001 | p-value | 0.0000 |
| Self-esteem (19) | −0.52 | 0.10 | 1.70 | 18.84 | 0.001 | Items fit residual (mean (SD)) | −0.09 (2.04) |
| Negative feeling (26) | 0.22 | 0.08 | 3.87 | 19.13 | 0.001 | Persons fit residual (mean (SD)) | −0.22 (0.90) |
| Social domain | |||||||
| Personal relationship (20) | −0.75 | 0.09 | −1.85 | 15.36 | 0.004 | Person separation index | 0.605 |
| Sexual activity (21) | −0.55 | 0.09 | −0.61 | 9.96 | 0.041 | Coefficient alpha | a |
| Social support (22) | 1.31 | 0.09 | 0.52 | 21.90 | 0.000 | Chi-square (Degrees of freedom) | 47.21 (12) |
| p-value | 0.0000 | ||||||
| Items fit residual (mean (SD)) | −0.64 (1.18) | ||||||
| Persons fit residual (mean (SD)) | −0.39 (0.71) | ||||||
| Environmental domain | |||||||
| Security (8) | −0.66 | 0.08 | −1.49 | 13.80 | 0.008 | Person separation index | 0.740 |
| Physical environment (9) | −0.05 | 0.08 | −0.86 | 6.94 | 0.139 | Coefficient alpha | 0.739 |
| Financial support (12) | 0.80 | 0.07 | −3.99 | 34.08 | 0.000 | Chi-square (Degrees of freedom) | 173.69 (32) |
| Accessibility of information (13) | 1.01 | 0.07 | −2.54 | 20.62 | 0.000 | p-value | 0.0000 |
| Leisure activity (14) | −0.19 | 0.07 | −0.28 | 8.64 | 0.071 | Items fit residual (mean (SD)) | −0.12 (2.73) |
| Home environment (23) | −0.79 | 0.08 | 2.14 | 10.50 | 0.033 | Persons fit residual (mean (SD)) | −0.24 (1.07) |
| Health care (24) | 0.53 | 0.09 | 1.62 | 22.32 | 0.000 | ||
| Transport (25) | −0.65 | 0.09 | 4.42 | 56.80 | 0.000 | ||
aCoefficient of Alpha cannot be calculated on missing data