TABLE 2.
Baseline demographics and characteristics for subjects enrolled in the PAS2 (Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma) study and AIR2 (Asthma Intervention Research 2) trial
| PAS2 | AIR2, bronchial thermoplasty | p-value | |
| Subjects | 190 | 190 | |
| Demographics | |||
| Age years | 45.87±11.39 (190) (18.00–66.00) |
40.69±11.89 (190) (18.00–63.00) |
<0.0001 |
| Female | 61.6 (117/190) | 57.4 (109/190) | 0.4032 |
| BMI kg·m−2 | 32.50±7.72 (190) (18.48–61.27) |
29.29±6.16 (190) (17.63–52.77) |
<0.0001 |
| Baseline medication usage | |||
| ICS dose μg·day−1 | 2301.04±807.46 (189) (750.00–6480.00) |
1960.74±745.19 (190) (880.00–6000.00) |
<0.0001 |
| LABA dose μg·day−1 | 106.87±39.36 (189) (75.00–416.67) |
116.8±34.39 (189) | 0.0031 |
| SABA puffs·day−1 | 2.38±1.48 (182) (1.00–18.00) |
2.24±1.29 (168) (1.00–8.00) |
0.3451 |
| Other asthma medications | |||
| OCS | 18.9 (36/190) | 4.2 (8/190) | <0.0001 |
| Dose mg·day−1 | 9.13±2.66 (35) (5.00–17.00) |
11.88±15.51 (8) (5.00–50.00) |
0.3125 |
| Methylxanthines | 4.2 (8/190) | 2.6 (5/190) | 0.3972 |
| Leukotriene modifier | 44.2 (84/190) | 0.0 (0/190) | <0.0001 |
| Omalizumab | 15.8 (30/190) | 1.1 (2/190) | <0.0001 |
| Dose mg·day−1 | 266.83±88.67 (30) (150.00–405.00) |
350.00±35.36 (2) (325.00–375.00) |
0.2026 |
| Other | 40.5 (77/190) | 31.1 (59/190) | 0.0541 |
| Any of the above maintenance medications | 70.5 (134/190) | 33.7 (64/190) | <0.0001 |
| Quality of life measurement: AQLQ | 4.17±1.33 (190) (1.56–6.59) |
4.30±1.17 (190) (1.63–6.28) |
0.2936 |
| ERS/ATS guidelines: modified definition of severe asthma# | 94.7 (180/190) | 82.1 (156/190) | 0.0001 |
| Spirometry | |||
| Pre-bronchodilator FEV1 % pred | 79.63±13.10 (190) (59.52–125.93) |
77.83±15.65 (190) (50.15–120.27) |
0.2255 |
| Post-bronchodilator FEV1 % pred | 84.82±12.90 (190) (65.09–130.69) |
86.06±15.76 (190) (56.09–130.29) |
0.4009 |
| Pre-bronchodilator FEV1 L | 2.54±0.65 (190) (1.28–4.93) |
2.59±0.73 (190) (1.31–5.68) |
0.4517 |
| Post-bronchodilator FEV1 L | 2.70±0.66 (190) (1.40–5.18) |
2.87±0.79 (190) (1.34–5.83) |
0.0225 |
| Medical history: how long the subject has been diagnosed with asthma years | 25.62±14.46 (190) (1.00–60.00) |
22.91±13.37 (190) (1.00–59.00) |
0.0591 |
| Prior 12 months | |||
| Subjects | |||
| Severe exacerbations | 74.2 (141/190) | 51.6 (98/190) | <0.0001 |
| Hospitalisations for asthma | 15.3 (29/190) | 4.2 (8/190) | 0.0003 |
| Emergency department visits for asthma | 27.4 (52/190) | 28.9 (55/190) | 0.7322 |
| Events | |||
| Severe exacerbations | 1.57±1.15 (190) (0.00–3.00) |
0.88±1.03 (190) (0.00–3.00) |
<0.0001 |
| Hospitalisations for asthma | 0.21±0.53 (190) (0.00–2.00) |
0.05±0.27 (190) (0.00–2.00) |
0.0003 |
| Emergency department visits for asthma | 0.52±1.16 (190) (0.00–10.00) |
0.74±1.71 (190) (0.00–10.00) |
0.1409 |
Data are presented as N, mean±sd (n or N) (range) or % (n/N), unless otherwise stated. BMI: body mass index; ICS: inhaled corticosteroid; LABA: long-acting β-agonist; SABA: short-acting β-agonist; AQLQ: Asthma Quality of Life Questionnaire; ERS: European Respiratory Society; ATS: American Thoracic Society; FEV1: forced expiratory volume in 1 s. #: the definition used for severe asthma was modified from the ERS/ATS guideline definition as Asthma Control Questionnaire and the Asthma Control Test scores were not collected for both studies; a subject was considered to have severe asthma if one of the following was true: baseline ICS ≥2000 μg·day−1 (beclomethasone equivalent) and LABA/leukotriene modifier usage; or two or more severe exacerbations in the 12 months prior to first bronchial thermoplasty; or one or more hospitalisations in the 12 months prior to first bronchial thermoplasty; or post-bronchodilator FEV1 % pred <80% and FEV1/forced vital capacity <0.7.