Background
Methods
Research population and data collection
HRQoL data
Data analysis
Hypotheses
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The ceiling with the EQ-5D + C is less than with the EQ-5D;
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The convergent validity of the EQ-5D + C with the EQ-VAS is higher than the convergent validity of the EQ-5D with the EQ-VAS in the group of TBI patients;
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The explanatory power of the EQ-5D + C is higher compared to the EQ-5D in TBI patients due to specific cognitive symptoms after TBI;
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The explanatory power of the EQ-5D is higher in non-TBI patients than in TBI patients due to more heterogeneity in type and nature of injury;
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Absolute classification efficiency of the EQ-5D + C is higher compared to the EQ-5D in the group of TBI patients, while relative classification efficiency is similar.
Results
Study population
Demographics of research population | Research population | TBI | Non-TBI | p value |
---|---|---|---|---|
n
| 2693 | 715 | 1978 | |
Mean age (SD) | 64.0 (18.3) | 61.4 (18.6) | 65.0 (18.1) | < 0.001* |
Females | 1326 (49.2%) | 305 (42.7%) | 1021 (51.6%) | < 0.001* |
Education level | ||||
Low | 898 (33.3%)a | 233 (32.6%)b | 665 (33.6%)c | 0.616 |
Medium | 963 (35.8%)a | 258 (36.1%)b | 705 (35.6%)c | 0.833 |
High | 752 (27.9%)a | 198 (27.7%)b | 554 (28.0%)c | 0.872 |
ISS scores | ||||
1–3 | 609 (22.6%)d | 358 (50.1%) | 251 (12.7%)d | < 0.001* |
4–8 | 921 (34.2%)d | 169 (23.6%) | 752 (38.0%)d | < 0.001* |
9–15 | 1005 (37.3%)d | 125 (17.5%) | 880 (44.5%)d | < 0.001* |
16+ | 141 (5.2%)d | 63 (8.8%) | 78 (3.9%)d | < 0.001* |
Severity of TBI | ||||
Mild | – | 550 (76.9%) | – | – |
Moderate | – | 65 (9.1%) | – | – |
Severe | – | 100 (14.0%) | – | – |
Comorbidity | ||||
n pre-existing conditions | ||||
0 | 1061 (39.4%) | 306 (42.8%) | 755 (38.2%) | 0.032* |
1 | 724 (26.9%) | 194 (27.1%) | 530 (26.8%) | 0.861 |
2 | 441 (16.4%) | 111 (15.5%) | 330 (16.7%) | 0.473 |
3+ | 467 (17.4%) | 104 (14.5%) | 363 (18.5%) | 0.016* |
Frequency of unique health states and ceiling effects
Convergent validity
Combination | Spearman’s rank correlation | |
---|---|---|
Research population | EQ-5D – EQ-VAS | − 0.673 |
EQ-5D + C – EQ-VAS | − 0.690 | |
TBI | EQ-5D – EQ-VAS | − 0.719 |
EQ-5D + C – EQ-VAS | − 0.736 | |
Non-TBI | EQ-5D – EQ-VAS | − 0.652 |
EQ-5D + C – EQ-VAS | − 0.665 |
Explanatory power
Combination of EQ-5D + C dimensions | Adjusted R2 | F value | P value |
---|---|---|---|
Research population | |||
MO, SC, UA, PD, AD | 0.480 | 249.1 | < 0.001* |
MO, SC, UA, PD, AD, CO | 0.499 | 224.5 | < 0.001* |
MO, UA, PD, AD, CO | 0.486 | 255.4 | < 0.001* |
MO, SC, PD, AD, CO | 0.477 | 246.8 | < 0.001* |
MO, SC, UA, AD, CO | 0.472 | 241.7 | < 0.001* |
MO, SC, UA PD, CO | 0.471 | 241.2 | < 0.001* |
SC, UA, PD, AD, CO | 0.487 | 256.4 | < 0.001* |
TBI patients | |||
MO, SC, UA, PD, AD | 0.528 | 80.9 | < 0.001* |
MO, SC, UA, PD, AD, CO | 0.560 | 76.6 | < 0.001* |
MO, UA, PD, AD, CO | 0.546 | 86.7 | < 0.001* |
MO, SC, PD, AD, CO | 0.533 | 82.3 | < 0.001* |
MO, SC, UA, AD, CO | 0.530 | 81.5 | < 0.001* |
MO, SC, UA PD, CO | 0.546 | 86.8 | < 0.001* |
SC, UA, PD, AD, CO | 0.546 | 87.0 | < 0.001* |
Non-TBI patients | |||
MO, SC, UA, PD, AD | 0.451 | 163.7 | < 0.001* |
MO, SC, UA, PD, AD, CO | 0.466 | 145.0 | < 0.001* |
MO, UA, PD, AD, CO | 0.452 | 164.3 | < 0.001* |
MO, SC, PD, AD, CO | 0.447 | 161.1 | < 0.001* |
MO, SC, UA, AD, CO | 0.441 | 157.2 | < 0.001* |
MO, SC, UA PD, CO | 0.433 | 151.9 | < 0.001* |
SC, UA, PD, AD, CO | 0.454 | 165.7 | < 0.001* |
Classification efficiency—Shannon’s indices
Health profiles | H′ | Adjusted H′ | J′ | Adjusted J′ |
---|---|---|---|---|
TBI | ||||
EQ-5D | 5.08 | 5.25 | 0.64 | 0.66 |
EQ-5D + C | 5.88 | 6.39 | 0.62 | 0.67 |
Non-TBI | ||||
EQ-5D | 5.58 | 5.64 | 0.70 | 0.71 |
EQ-5D + C | 6.38 | 6.56 | 0.67 | 0.69 |