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Table 4 Summary of observed and predicted values by EQ-5D group and FEV 1 severity

From: Mapping the EQ-5D index from the cystic fibrosis questionnaire-revised using multiple modelling approaches

Observed EQ-5D range N Observed EQ-5D OLS models Tobit models TPM models
Domain (3) Item (5) Domain (3) Item (5) Domain (3) Item (8)
−0.349 - 0.099 23 −0.028 0.294 (0.321) 0.197 (0.225) 0.293 (0.320) 0.185 (0.214) 0.274 (0.307) 0.160 (0.196)
0.1 - 0.299 41 0.227 0.420 (0.211) 0.337 (0.149) 0.421 (0.209) 0.335 (0.148) 0.418 (0.214) 0.320 (0.134)
0.3 - 0.599 38 0.511 0.505 (0.130) 0.518 (0.106) 0.502 (0.136) 0.517 (0.113) 0.524 (0.135) 0.532 (0.100)
0.6 - 0.699 92 0.660 0.620 (0.106) 0.643 (0.093) 0.621 (0.110) 0.643 (0.098) 0.649 (0.115) 0.655 (0.092)
0.7 - 0.799 71 0.756 0.747 (0.084) 0.736 (0.088) 0.749 (0.093) 0.737 (0.097) 0.778 (0.099) 0.761 (0.089)
0.8 - 0.899 59 0.841 0.794 (0.109) 0.804 (0.097) 0.792 (0.103) 0.804 (0.100) 0.817 (0.101) 0.816 (0.099)
0.9 - 1 77 1 0.895 (0.107) 0.938 (0.088) 0.900 (0.100) 0.949 (0.051) 0.916 (0.084) 0.948 (0.052)
ANOVA    F = 107.30 F = 176.10 F = 105.70 F = 183.84 F =104.81 F = 202.73
p < 0.001 p < 0.001 p < 0.001 p < 0.001 p < 0.001 p < 0.001
FEV 1
Severe < 41% 92 0.552 0.550 (0.157) 0.548 (0.132) 0.548 (0.158) 0.550 (0.133) 0.565 (0.157) 0.561 (0.121)
Moderate 41-70% 136 0.695 0.684 (0.119) 0.694 (0.107) 0.683 (0.120) 0.693 (0.101) 0.703 (0.120) 0.702 (0.099)
Mild > 70% 105 0.741 0.755 (0.113) 0.748 (0.097) 0.760 (0.116) 0.751 (0.090) 0.781 (0.111) 0.757 (0.076)
ANOVA    F = 24.38 F = 19.29 25.39 F = 18.43 F = 23.83 F = 16.76
p< 0.001 p< 0.001 p < 0.001 p < 0.001 p < 0.001 p < 0.001
  1. OLS, ordinary least squares; TPM, two-part model; FEV1, percentage of predicted Forced Expiratory Volume in 1 second.
  2. Model 3 = CFQ-R domains that are statistically significant at the 10% level + statistically significant squared terms; Model 5 = All CFQ-R items excluding the health domain items; TPM Model 8 = All CFQ-R items excluding the health domain items + age and gender.