Table 3 Construct validity and responsiveness of CaReQoL Asthma (t38 or t64)
CaReQoL domain (scores at t38 or t64) | Comparison instruments: change scores (∆ t0–t38 or ∆ t0–t64) | Expected correlation strength# (direction) | Construct validity and responsiveness (t38) | Respon-siveness (t64) | Explanation/hypothesis |
|---|---|---|---|---|---|
Physical functioning (8 items) | Δ AQLQ: Total score Symptoms Activity limitations Emotional functioning Environmental stimuli | 0.40–0.59 (+) 0.40–0.59 (+) 0.40–0.59 (+) 0.00–0.39 (+) 0.00–0.39 (+) | 0.48*** 0.53*** 0.39** 0.15 (n.s.) 0.29* | 0.45** 0.44** 0.44** 0.30 (n.s.) 0.32* | Physical functioning is likely to be moderately related with changes in Total, Activity limitations and Symptoms scores, but not to other AQLQ scores |
Δ ACQ | 0.40–0.59 (−) | − 0.52*** | − 0.55*** | Physical functioning is likely to be moderately related to a change in ACQ | |
Δ FEV1 | 0.00–0.39 (+) | 0.25 (n.s.) | 0.15 (n.s.) | Physical functioning is expected to be weakly related to a change in FEV1 | |
Social functioning (4 items) | Δ AQLQ: Total score Symptoms Activity limitations Emotional functioning Environmental stimuli | 0.40–0.59 (+) 0.00–0.39 (+) 0.40–0.59 (+) 0.00–0.39 (+) 0.00–0.39 (+) | 0.49*** 0.48*** 0.45*** 0.10 (n.s.) 0.42*** | 0.45** 0.40** 0.49** 0.14 (n.s.) 0.38* | Social functioning is likely to be moderately related to changes in the Total score and Activity limitations, but not to other AQLQ scores |
Δ ACQ | 0.40–0.59 (−) | − 0.53*** | − 0.43** | Social functioning is likely to be moderately related to a change in ACQ | |
Δ FEV1 | 0.00–0.39 (+) | 0.19 (n.s.) | 0.07 (n.s.) | Social functioning is expected to be weakly related to a change in FEV1 | |
Coping with asthma (5 items) | Δ AQLQ: Total score Symptoms Activity limitations Emotional functioning Environmental stimuli | 0.00–0.39 (+) 0.00–0.39 (+) 0.00–0.39 (+) 0.40–0.59 (+) 0.00–0.39 (+) | 0.16 (n.s.) 0.20 (n.s.) 0.09 (n.s.) 0.18 (n.s.) 0.06 (n.s.) | 0.32* 0.24 (n.s.) 0.37* 0.07 (n.s.) 0.38* | Coping is likely to be moderately related to changes in Emotional function, but not to other AQLQ scores |
Δ ACQ | 0.40–0.59 (−) | − 0.14 (n.s.) | − 0.46** | Coping is expected to be moderately related to a change in ACQ | |
Δ FEV1 | 0.00–0.39 (+) | 0.17 (n.s.) | 0.01 (n.s.) | Coping is expected to be weakly related to a change in FEV1 | |
Knowledge about asthma (3 items) | Δ AQLQ: Total score Δ ACQ Δ FEV1 | 0.00–0.39 (+) 0.00–0.39 (−) 0.00–0.39 (+) | 0.17 (n.s.) − 0.15 (n.s.) 0.14 (n.s.) | 0.36* − 0.23 (n.s.) 0.10 (n.s.) | Since there are no similar items on Knowledge about asthma in all other measures, correlations are expected to be very weak |
Medication (3 items) | Δ AQLQ: Total score Symptoms Activity limitations Emotional functioning Environmental stimuli | 0.00–0.39 (+) 0.40–0.59 (+) 0.00–0.39 (+) 0.00–0.39 (+) 0.00–0.39 (+) | 0.38** 0.48*** 0.29* 0.02 (n.s.) 0.27* | 0.23 (n.s.) 0.19 (n.s.) 0.28 (n.s.) -0.04 (n.s.) 0.28 (n.s.) | Medication is likely to be moderately related to changes in Symptoms, but not to other AQLQ scores |
Δ ACQ | 0.40–0.59 (−) | − 0.47*** | − 0.35* | Since 1 item of the ACQ concerns the use of medicine, a moderate correlation is expected | |
Δ FEV1 | 0.00–0.39 (+) | 0.08 (n.s.) | 0.00 (n.s.) | Medication is expected to be weakly related to a change in the FEV1 | |
Overall quality of life (QoL) (1 item) | Δ AQLQ: Total score Symptoms Activity limitations Emotional functioning Environmental stimuli | 0.40–0.59 (+) 0.40–0.59 (+) 0.00–0.39 (+) 0.00–0.39 (+) 0.00–0.39 (+) | 0.40** 0.41*** 0.30* 0.24 (n.s.) 0.37** | 0.34* 0.27 (n.s.) 0.40* 0.05 (n.s.) 0.37* | The perceived effect on QoL is likely to be moderately related to changes in the Total and Symptoms scores, and weakly related to other AQLQ scores |
Δ ACQ | 0.40–0.59 (−) | − 0.34** | − 0.45** | The overall quality of life is likely to be moderately related to a change in ACQ | |
Δ FEV1 | 0.00-0.39 ( +) | 0.15 (n.s.) | 0.14 (n.s.) | The effect on QoL is expected to be weakly related to a change in the predicted FEV1 | |
Global perceived effect (GPE) (1 item) | Δ AQLQ: Total score Symptoms Activity limitations Emotional functioning Environmental stimuli | 0.40–0.59 (+) 0.40–0.59 (+) 0.00–0.39 (+) 0.00–0.39 (+) 0.00–0.39 (+) | 0.46*** 0.47*** 0.43*** 0.09 (n.s.) 0.33** | 0.46** 0.40** 0.51*** 0.18 (n.s.) 0.38* | This criterion variable GPE is expected to be moderately related to changes in the Total and Symptoms scores, and weakly related to changes in other AQLQ scores |
Δ ACQ | 0.40–0.59 (−) | − 0.53*** | − 0.50** | The GPE is expected to be moderately related to a change in ACQ | |
Δ FEV1 | 0.00–0.39 ( +) | 0.18 (n.s.) | 0.20 (n.s.) | The GPE is expected to be weakly related to the FEV1 |