Table 1.
Baseline Characteristics
| Variable | Diagnosed Asthma (N = 245,893) |
|---|---|
| Age (years), mean (SD), median | 44.8 (22.1), 45.0 |
| Male, n (%) | 107,763 (43.8) |
| Smoking status, n (%) | |
| Never smoked | 140,829 (60.5) |
| Current smoker | 37,218 (16.0) |
| Ex-smoker | 54,912 (23.6) |
| No data on smoking status | 12,934 (5.3) |
| FEV1% predicted, mean (SD)a, median | 85.3 (22.4), 87.0 |
| GINA treatment stepb, n (%) | |
| 1 | 23,919 (9.7) |
| 2 | 61,791 (25.1) |
| 3 | 61,276 (24.9) |
| 4 | 95,526 (38.8) |
| 5 | 3381 (1.4) |
| Exacerbations, ATS definitionc, n (%) | |
| 0 | 204,910 (83.3) |
| 1 | 30,420 (12.4) |
| 2 | 7257 (3.0) |
| ≥3 | 3306 (1.3) |
| Patients having overall asthma controld, n (%) | 117,423 (47.8) |
Notes: aNumber of patients with non-missing data = 110,946. bGINA step 1: short-acting relievers only; GINA step 2: low-dose inhaled corticosteroid (ICS) without controllers, leukotriene receptor (LTRA) without controllers, theophylline without controllers, sodium cromoglicate, or nedocromil sodium; GINA step 3: medium- or high-dose ICS without controllers, low-dose ICS/long-acting beta agonist (LABA), low-dose ICS/long-acting muscarinic antagonist (LAMA), low-dose ICS without LABA or LAMA plus LTRA and/or theophylline, LABA and/or LAMA without ICS, LTRA plus theophylline without ICS; GINA step 4: medium- or high-dose ICS/LABA, medium- or high-dose ICS/LAMA, medium- or high-dose ICS plus LTRA and/or theophylline, low-dose ICS/LABA plus ≥1 controller, low-dose ICS/LAMA plus ≥1 controller, ≥3 controllers without ICS; GINA step 5: maintenance OCS plus other treatment or anti-immunoglobulin-E therapy. cIncludes one or more occurrences of any of the following: asthma-related hospital admission or A&E attendance or an acute course of oral corticosteroids. dControlled asthma, defined as the absence of the following: an asthma-related A&E attendance, inpatient admission or outpatient department attendance, an acute course of oral corticosteroids with evidence of a lower respiratory consultation, an antibiotic prescribed with evidence of a lower respiratory consultation; and limited use of short-acting beta-2 agonists (average daily short-acting β-agonist dose not exceeding 200 μg salbutamol or >500 μg terbutaline).
Abbreviations: ATS, American Thoracic Society; FEV1, forced expiratory flow in 1 second; GINA, Global Initiative for Asthma; SD, standard deviation.