Table 5.
Efficiency of multi-attribute utility measures to detect differences in self-reported health status; women for whom both utility scores were between 0.296 and 1.0 (n = 481)
| 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) | 8.682 | <0.001 | 1.000 | 0.712* | (0.655, 0.768) |
| Very good, good, fair or poor | 0.861 | (0.137) | ||||||
| SF-6D | Excellent | 0.916 | (0.091) | 10.038 | <0.001 | 1.337 | 0.792* | (0.741, 0.844) |
| Very good, good, fair or poor | 0.794 | (0.129) | ||||||
| EQ-5D | Excellent or very good | 0.931 | (0.103) | 10.029 | <0.001 | 1.000 | 0.747* | (0.699, 0.795) |
| Good, fair or poor | 0.804 | (0.143) | ||||||
| SF-6D | Excellent or very good | 0.876 | (0.106) | 13.816 | <0.001 | 1.898 | 0.835* | (0.797, 0.872) |
| Good, fair or poor | 0.725 | (0.114) | ||||||
| EQ-5D | Excellent, very good or good | 0.897 | (0.124) | 8.672 | <0.001 | 1.000 | 0.829* | (0.763, 0.896) |
| Fair or poor | 0.716 | (0.126) | ||||||
| SF-6D | Excellent, very good or good | 0.833 | (0.123) | 9.663 | <0.001 | 1.242 | 0.834* | (0.775, 0.894) |
| Fair or poor | 0.661 | (0.105) | ||||||
| EQ-5D | Excellent, very good, good or fair | 0.882 | (0.134) | 6.482 | 0.018 | 1.000 | 0.720 | (0.471, 0.970) |
| Poor | 0.678 | (0.053) | ||||||
| SF-6D | Excellent, very good, good or fair | 0.818 | (0.l30) | 10.121 | 0.006 | 2.438 | 0.770* | (0.544, 0.997) |
| Poor | 0.583 | (0.039) | ||||||
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.