TABLE 4.
Test-retest reliability, internal consistency and validity of some of the asthma tools used for measuring and reporting asthma symptoms/asthma control
| Test | Test-retest reliability | Internal consistency | Validity |
| Asthma Symptom Utility Index | Yes Intraclass correlation coefficient: 0.74 |
Yes | Yes, compared with indicators of disease severity (medical history instrument, lung function, physician severity rating scale and Juniper asthma disease severity scale), generic health utility (HUI Mark 2), Asthma Quality of Life Questionnaire |
| Asthma Control Questionnaire | Yes Intraclass correlation coefficient: 0.90 |
Yes | Yes, in comparison to Asthma Quality of Life Questionnaire (AQLQ) and the Medical Outcomes Survey Short Form-36 (SF-36), clinician global rating of change (based on consultation with the patient, spirometry, 1-week diary of short-acting β2-agonist use and morning pre-bronchodilator peak expiratory flow, AQLQ and SF-36 data) |
| Asthma Control Test | Yes Test-retest reliability: 0.77 |
Yes Cronbach's α=0.84–0.85 (cross-sectionally); 0.79 (longitudinally) |
Yes, correlation with specialist's rating of asthma control based on history, physical examination and FEV1 |
FEV1: forced expiratory volume in 1 s.