| Instrument | Construct validity# Pearson's correlation coefficient (r) | Discriminant/known-groups validity¶ |
| C-ACT [41] | PAQLQ+ [52] domain scores, r = 0.47 PACQLQ [50] domain scores, r = 0.68 | Specialist rating of asthma control (p<0.0001) Change in patient therapy (p<0.0001) FEV1 % pred (p = 0.0494) FEV1/FVC (ns) |
| CAN [42] | FEV1 r = -0.136 (p = 0.026) | Asthma severity (p<0.001) Symptom intensity Cough (p<0.001) Wheezing (p<0.001) Breathlessness (p<0.001) Presence of exacerbations (p<0.001) Intensity of exacerbations (p<0.001) |
| PACD [18] | PACQLQ [50] activity change over 21 days Symptom/activity scale r = -0.27 (SS) DWAS r = 0.19 (SS) PACQLQ emotional change over 21 days Symptom/activity scale r = -0.34 (SS) DWAS r = 0.32 (SS) Change in physician severity rating Symptom/activity scale r = -0.43 (SS) DWAS r = -0.37 (SS) Change in β-agonist treatments Symptom/activity scale r = 0.65 (SS) DWAS not applicable Change in physician global assessment Symptom/activity scale r = 0.39 (SS) DWAS r = -0.28 (SS) Change in caregiver global assessment Symptom/activity scale r = 0.47 (SS) DWAS r = -0.28 (SS) | Asthma status, stable versus unstable+ adjusted for age and clinic Symptom/activity scale (p = 0.0001) Mean per cent DWAS 37% in stable group versus 11% in unstable group (p = 0.0001) |
| PACT [44] | ITG Child Asthma Short Form (QOL measure) [53] Frequency of flares domain r = 0.61 (p<0.01) Symptoms at best domain r = 0.77 (p<0.01) Specialist clinician assessment Frequency of flares domain r = 0.54 (p<0.01) Symptoms at best domain r = 0.59 (p<0.01) FEV1 % pred Frequency of flares domain r = -0.12 (ns) Symptoms at best domain r = -0.29 (p<0.01) | Not reported |
| PedsQL 3.0 SF22 Asthma Module§ [46] | Impact on Family Scale [54] Asthma symptoms r = -0.14 (p<0.01) Treatment problems r = -0.19 (p<0.01) School and sports days missed by child Asthma symptoms r = -0.33 (p<0.01) Treatment problems r = -0.34 (p<0.01) Work days missed by parent Asthma symptoms r = -0.28 (p<0.01) Treatment problems r = -0.26 (p<0.01) | Asthma severity level, post hoc pairwise comparisons for both scales: Mild intermittent versus mild persistent (p<0.05) Mild persistent versus moderate-severe persistent (p<0.05) Mild intermittent versus moderate-severe persistent (p<0.05) |
| PedsQL Asthma Symptoms Scale [45] | PedsQL 4.0 Generic Core Scales [55] Total score r = 0.49 (p<0.001) | Asthma severity level (mild, moderate, severe): Mild versus severe (p<0.001) Mild versus moderate (p<0.001) ns difference between moderate and severe |
| TRACK [47] | Not reported (factor analysis conducted) | Physician rating of control (p<0.001) [47, 50] Physician recommendation for change in therapy (p<0.001) [47, 50] Symptom frequency (p<0.001) [47] Caregiver-reported frequency of asthma attacks in past 3 months at baseline (p<0.001) [50] |
C-ACT: Childhood Asthma Control Test; CAN: Control de Asma en Niños (Control of Asthma in Children); PACD: Pediatric Asthma Caregiver Diary; PACT: Pediatric Asthma Control Tool; PedsQL 3.0 SF22 Asthma Module: Paediatric Quality of Life Inventory 3.0 SF22 Asthma Module; PedsQL Asthma Symptoms Scale: Paediatric Quality of Life Inventory 3.0 Asthma Module Asthma Symptoms Scale (proxy-reported version); TRACK: Test for Respiratory and Asthma Control in Kids; PAQLQ: Pediatric Asthma Quality of Life Questionnaire; PACQLQ: Pediatric Asthma Caregiver's Quality of Life Questionnaire; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; ns: not statistically significant; DWAS: day without asthma symptoms; SS: statistically significant, level not specified; ITG: Integrated Therapeutics Group; QOL: quality of life. #: all reported evidence of construct validity was related to convergent validity. Correlation values are categorised as <0.10, weak; 0.10−0.50, moderate; and >0.50, strong [56]. ¶: comparison of mean instrument scores across patients differing in the categories presented. +: assessed at baseline of a 3-week study; stable, requiring no change in anti-inflammatory asthma therapy (inhaled corticosteroids or cromolyn); unstable, unstable asthma or asthma exacerbation requiring addition of new anti-inflammatory asthma therapy or an increase in anti-inflammatory asthma therapy. §: both the parent-reported (children aged 2–11 years) and the child self-reported (children aged 12–18 years) versions of the PedsQL 3.0 SF22 Asthma Module were validated in Chan et al. [46]; 125 adolescents and 338 parents composed the sample (average age of asthmatic child, 9.0 years). Separate results by version were not provided for validity assessments.