Table 4.
Comparison between health utility value sets generated by time trade-off and discrete-choice experiments with a duration dimension
| TTO (adjusted) | DCETTO | |
|---|---|---|
| Coef. | Coef. | |
| Physical functioning | ||
| PF1 | 0.000 | 0.000 |
| PF2 | − 0.038 | − 0.027 |
| PF3 | − 0.080 | − 0.050 |
| PF4 | − 0.140 | − 0.145 |
| PF5 | − 0.395 | − 0.404 |
| Role limitation | ||
| RL1 | 0.000 | 0.000 |
| RL2 | − 0.050 | − 0.029 |
| RL3 | − 0.059 | − 0.030 |
| RL4 | − 0.096 | − 0.081 |
| RL5 | − 0.097 | − 0.112 |
| Social functioning | ||
| SF1 | 0.000 | 0.000 |
| SF2 | − 0.047 | − 0.035 |
| SF3 | − 0.060 | − 0.038 |
| SF4 | − 0.093 | − 0.104 |
| SF5 | − 0.108 | − 0.114 |
| Pain | ||
| PN1 | 0.000 | 0.000 |
| PN2 | − 0.047 | − 0.072 |
| PN3 | − 0.083 | − 0.079 |
| PN4 | − 0.154 | − 0.155 |
| PN5 | − 0.388 | − 0.466 |
| PN6 | − 0.427 | − 0.541 |
| Mental health | ||
| MH1 | 0.000 | 0.000 |
| MH2 | − 0.033 | 0.000 |
| MH3 | − 0.050 | − 0.010 |
| MH4 | − 0.132 | − 0.146 |
| MH5 | − 0.134 | − 0.197 |
| Vitality | ||
| VT1 | 0.000 | 0.000 |
| VT2 | − 0.029 | 0.000 |
| VT3 | − 0.060 | − 0.083 |
| VT4 | − 0.108 | − 0.089 |
| VT5 | − 0.116 | − 0.167 |
| No. (%) of worse than death | 927 (4.94%) | 1593 (8.50%) |
| The worst state value (555655) | − 0.277 | − 0.535 |
| MAD | 0.0588 | |
| MSD | 0.0055 | |
| ICC | 0.9804 | |
The value set generated by TTO was based on model 2 (random-effects model) shown in Table 2, and the linear adjustment to remove the effect of the non-zero intercept was made using the formula UAdjusted = UPredicted/(1 − intercept). The value set generated by DCETTO was based on the anchored coefficients of the conditional logit model (Table 3) with the combination of inconsistent coefficients
Coef. coefficient, DCETTO discrete-choice experiments with a duration dimension, ICC intraclass correlation coefficient, MAD mean absolute difference, MH mental health, MSD mean squared difference, PF physical functioning, PN pain, RL role limitation, SF social functioning, TTO time trade-off, VT vitality