Table 2.
Parent N = 277/369 | Child N = 233/240 | |
---|---|---|
Missing values (1st–3rd quartiles) | 0.0 (0.0–0.4) | 0.0 (0.0–0.4) |
Response pattern | PF and HRQoL positively skewed | PF and HRQoL positively skewed |
Floor effect, median | ||
PF | 85.9% | 88.0% |
HRQoL PhH | 68.8% | 71.2% |
HRQoL PsH | 67.1% | 69.5% |
Pain VAS | 33.9% | 33.1% |
Disease activity VAS | 35.7% | 40.3% |
Well-being VAS | 41.9% | 48.9% |
Ceiling effect, median | ||
PF | 0.4% | 0.0% |
HRQoL PhH | 2.2% | 3.0% |
HRQoL PsH | 1.1% | 0.4% |
Pain VAS | 0.0% | 0.0% |
Disease activity VAS | 4.0% | 0.0% |
Well-being VAS | 0.7% | 0.4% |
Items with equivalent item-scale correlation | 87% for PF, 80% for HRQoL | 80% for PF, 87% for HRQoL |
Items with items-scale correlation ≥ 0.4 | 87% for PF, 100% for HRQoL | 80% for PF, 90% for HRQoL |
Cronbach’s alpha | ||
PF-LL | 0.88 | 0.81 |
PF-HW | 0.87 | 0.81 |
PF-US | 0.72 | 0.71 |
HRQoL-PhH | 0.86 | 0.87 |
HRQoL-PsH | 0.77 | 0.73 |
Items with item-scale correlation lower than the Cronbach alpha | 100% for PF, 100% for HRQoL | 100% for PF, 100% for HRQoL |
Test–retest intraclass correlation | ||
PF total score | 0.92 | 0.47 |
HRQoL-PhH | 0.92 | 0.71 |
HRQoL-PsH | 0.83 | 0.11 |
Spearman’s correlation with JIA core-set variables, median | ||
PF | 0.4 | 0.3 |
HRQoL PhH | 0.3 | 0.3 |
HRQoL PsH | 0.2 | 0.1 |
Pain VAS | 0.2 | 0.3 |
Disease activity VAS | 0.2 | 0.2 |
Well-being VAS | 0.3 | 0.3 |
JAMAR Juvenile Arthritis Multidimensional Assessment Report, JIA juvenile idiopathic arthritis, VAS visual analogue scale, PF physical function, HRQoL health-related quality of life, PhH physical health, PsH psychosocial health, PF-LL PF-lower limbs, PF-HW PF-hand and wrist, PF-US PF-upper segment