Table 4.
Efficiency of multi-attribute utility measures to detect differences in self-reported health status; all women (n = 493)
| Measure | Categorisation of self-reported health status | Utility score | t-testa | Relative efficiencyb | ROC curve | |||
| Mean | (SD) | t-statistic | p-value | Areac | 95% CI | |||
| EQ-5D | Excellent | 0.964 | (0.085) | 9.334 | <0.001 | 1.000 | 0.721* | (0.666, 0.776) |
| Very good, good, fair or poor | 0.837 | (0.189) | ||||||
| SF-6D | Excellent | 0.916 | (0.091) | 10.604 | <0.001 | 1.291 | 0.798* | (0.748, 0.849) |
| Very good, good, fair or poor | 0.784 | (0.138) | ||||||
| EQ-5D | Excellent or very good | 0.925 | (0.119) | 9.156 | <0.001 | 1.000 | 0.756* | (0.709, 0.802) |
| Good, fair or poor | 0.765 | (0.213) | ||||||
| SF-6D | Excellent or very good | 0.874 | (0.108) | 14.205 | <0.001 | 2.407 | 0.841* | (0.804, 0.877) |
| Good, fair or poor | 0.712 | (0.125) | ||||||
| EQ-5D | Excellent, very good or good | 0.890 | (0.145) | 7.222 | <0.001 | 1.000 | 0.849* | (0.790, 0.908) |
| Fair or poor | 0.616 | (0.258) | ||||||
| SF-6D | Excellent, very good or good | 0.830 | (0.127) | 10.742 | <0.001 | 2.212 | 0.852* | (0.800, 0.905) |
| Fair or poor | 0.634 | (0.119) | ||||||
| EQ-5D | Excellent, very good, good or fair | 0.867 | (0.169) | 3.469 | 0.018 | 1.000 | 0.814* | (0.633, 0.996) |
| Poor | 0.366 | (0.353) | ||||||
| SF-6D | Excellent, very good, good or fair | 0.813 | (0.136) | 7.938 | <0.001 | 5.236 | 0.847* | (0.686, 1.000) |
| Poor | 0.507 | (0.093) | ||||||
SD denotes standard deviation. ROC denotes receiver operating characteristic. CI denotes confidence interval.
a Not assuming equality of variance as Levene test showed statistically significant differences in variances between self-reported health status groups.
b Relative efficiency statistic is referenced to 1.0 for the EQ-5D measure. A value higher than 1.0 indicates that the SF-6D is more efficient than the EQ-5D in detecting differences between women in terms of their self-reported health status.
c Area under receiver operating characteristic (ROC) curves; * p < 0.05 indicates that area under the ROC curve was statistically significantly greater than 0.5 and that measure has discriminatory power.