Factor loading across studies and time (varimax rotation) for placebo patients only
| Study number (baseline) | Week (all studies) | ||||||
| 1 | 2 | 3 | 0 | 4 | 8 | 12 | |
| AQLQ activities | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| AQLQ environment | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| AQLQ symptoms | 1,3 | 1 | 1 | 1 | 1 | 1 | 1 |
| AQLQ emotions | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| FEV1 % pred | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| PEF pm | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| PEF am | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| FVC | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| FEF | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| Night-time waking | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Night-time β2‐agonist use | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Night-time symptoms | 3,4 | 3 | 3 | 3,4 | 3,4 | 4,3 | 4,3 |
| Nights without β2‐agonist % | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Nights without waking % | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Short of breath daytime | 4 | 4 | 4 | 4 | 4,1 | 4 | 4 |
| Activity limitation | 4 | 4,1 | 4,1 | 4 | 4,1 | 4 | 4 |
| ΔPEF am–pm | 1,4 | 4 | 4 | 4 | 4 | 4 | 4 |
| Chest tightness daytime | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
| Wheeze daytime | 4 | None | None | 4 | 4 | 4 | 4 |
| β2‐agonist use daytime | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
| Days without β2‐agonist % | 4 | None | None | 4 | 4 | 4 | 4 |
Factors (1, 2, 3 or 4) onto which each of the 21 items loaded with statistical significance
If an item loaded on two factors, the one onto which it loaded most strongly is shown first
AQLQ: Asthma Quality of Life Questionnaire
FEV1: forced expiratory volume in one second
PEF: peak expiratory flow
FVC: forced vital capacity
FEF: forced expiratory flow