TABLE 1.
Baseline clinical characteristics of frequent exacerbators (≥2/year) and infrequent exacerbators (<2/year)
| Infrequent | Frequent | p Value | |
|---|---|---|---|
| N | 156 | 264 | |
| Sex: female a | 83/156 (53.2) | 177/264 (67.1) | 0.007 |
| Age (yr) b | 52.53 (1.06) [156] | 51.67 (0.83) [264] | 0.449 |
| BMI (kg/m2) b | 28.74 (0.42) [156] | 29.53 (0.42) [264] | 0.560 |
| Age at diagnosis(year) b | 29.78 (1.55) [148] | 24.8 (1.13) [262] | 0.010 |
| Smoking status a | |||
| Current smoker | 22/156 (14.1) | 20/264 (7.6) | 0.047 |
| Ex‐smoker | 39/156 (25) | 76/264 (28.8) | 0.467 |
| Never smoked | 95/156 (60.9) | 168/264 (63.6) | 0.648 |
| Atopy test positive a | 111/133 (83.5) | 163/225 (72.4) | 0.025 |
| Allergic rhinitis diagnosed a | 72/140 (51.4) | 135/237 (57.0) | 0.349 |
| Diabetes diagnosed a | 13/145 (9.0) | 29/250 (11.6) | 0.516 |
| Eczema diagnosed a | 41/146 (28.1) | 96/248 (38.7) | 0.042 |
| Non‐allergic rhinitis diagnosed a | 22/143 (15.4) | 37/241 (15.4) | 1.000 |
| Sinusitis diagnosed a | 37/144 (25.7) | 94/248 (37.9) | 0.018 |
| Nasal polyps diagnosed a | 53/147 (36.1) | 84/244 (34.4) | 0.828 |
| Osteoporosis diagnosed a | 31/141 (22.0) | 69/246 (28.1) | 0.234 |
| GORD diagnosed a | 74/146 (50.7) | 124/241 (51.5) | 0.967 |
| Regular xanthine use a | 23/146 (15.8) | 57/242 (23.6) | 0.087 |
| Regular leukotriene modifier use a | 63/149 (42.3) | 120/254 (47.2) | 0.389 |
| Regular use of LAMA a | 36/144 (25) | 55/236 (23.3) | 0.801 |
| Regular SABA use a | 117/154 (76.0) | 224/251 (89.2) | p < 0.001 |
| Regular omalizumab use a | 24/145 (16.6) | 42/239 (17.6) | 0.906 |
| Regular OCS use a | 58/148 (39.2) | 123/249 (49.4) | 0.061 |
| FEV1 (% predicted) b | 68.36 (1.66) [156] | 66.81 (1.34) [261] | 0.455 |
| FVC (% predicted) b | 89.17 (1.52) [156] | 86.96 (1.2) [261] | 0.166 |
| Residual volume (L) b | 2.61 (0.07) [122] | 2.77 (0.08) [177] | 0.612 |
| sGaw (s−1 kPa−1) b | 0.93 (0.07) [115] | 0.89 (0.06) [173] | 0.219 |
| TLC (L)b | 5.85 (0.04) [156] | 5.82 (0.03) [263] | 0.550 |
| IgE (IU/ml) c | 144 (71‐368) [152] | 106 (41‐310) [253] | 0.026 |
| FeNO (ppb) c | 27 (15‐52) [146] | 24.5 (15‐46) [247] | 0.326 |
| Blood eosinophils (%) c | 2.95 (1‐6) [153] | 2.91 (1‐5) [254] | 0.354 |
| Blood neutrophils (%) c | 60.9 (55‐68) [153] | 62.98 (56‐71) [254] | 0.155 |
| Sputum eosinophils (%) c | 3.98 (1‐14) [65] | 2.9 (0‐16) [115] | 0.830 |
| Sputum neutrophils (%) c | 52.69 (43‐71) [65] | 55.1 (32‐75) [115] | 0.909 |
| Mean ACQ5 b | 1.98 (0.1) [136] | 2.44 (0.08) [236] | p < 0.001 |
| Mean AQLQ b | 4.67 (0.11) [135] | 4.35 (0.08) [232] | 0.015 |
| Total HADS b | 11.5 (0.79) [108] | 13.32 (0.6) [186] | 0.060 |
| Total SNOT20 b | 31.43 (1.52) [138] | 31.97 (1.11) [241] | 0.712 |
| Total ESS b | 7.35 (0.37) [137] | 7.76 (0.29) [234] | 0.372 |
Abbreviations: ACQ5, Asthma Control Questionnaire (five questions); AQLQ, asthma quality of life questionnaire; BMI, body metabolic index; ESS, Epworth Sleepiness Scale; FeNO, fractional level of nitric oxide in exhaled breath; FEV1, forced expiratory volume in one second; FVC, forced vital capacity; GORD, gastro‐oesophageal reflux disease; HADS, Hospital Anxiety and Depression Scale; IgE, immunoglobulin E; LAMA, long‐acting muscarinic antagonist; OCS, oral corticosteroid; Ppb, parts per billion; SABA, short‐acting β‐agonist; sGaw, specific airway conductance; SNOT20, sinonasal outcome test (20 questions); TLC, total lung capacity.
Number (percentage).
Mean (SD).
Median (interquartile range).