Table 3. Demographic and baseline characteristics of the less-smoking and the more-smoking groups.
| Less-smoking* (n=60) | More-smoking* (n=163) | p-value | |
|---|---|---|---|
| Age, yr | 64.6±11.8 | 67.0±8.4 | 0.141 |
| Male sex | 20 (33.3) | 154 (94.5) | <0.001 |
| Smoking status | |||
| Pack-year | 1.7±3.5 | 46.1±34.3 | <0.001 |
| Current/Ex-/Never smoker | 7 (11.7)/9 (15.0)/44 (73.3) | 65 (39.9)/98 (60.1)/0 (0) | <0.001 |
| Age at symptom onset, yr | 51.5±14.3 | 53.4±15.3 | 0.407 |
| Duration of treatment, yr | 6.9±5.5 | 8.0±7.2 | 0.233 |
| Asthma diagnosis before age 40 | 11 (18.3) | 29 (17.8) | 1.000 |
| Other allergic disease | 21 (35.0) | 33 (20.2) | 0.033 |
| Post-bronchodilator FEV1, % predicted | 62.0±12.5 | 58.7±14.0 | 0.103 |
| Post-bronchodilator FEV1/FVC, % | 57.9±11.0 | 49.1±10.4 | <0.001 |
| Change in FEV1, mL | 327.9±194.3 | 376.6±203.6 | 0.127 |
| Change in FEV1, % | 23.7±12.2 | 26.9±17.4 | 0.146 |
| Patient reported outcome | |||
| ACT score | 20.0±4.4 | 18.3±6.0 | 0.026 |
| CAT score | 13.2±9.2 | 13.0±8.6 | 0.882 |
| PHQ-9 score | 3.9±5.2 | 3.5±4.4 | 0.610 |
| Comorbidity | |||
| Rhinosinusitis | 10 (16.7) | 13 (8.0) | 0.080 |
| Gastroesophageal reflux | 8 (13.3) | 20 (12.3) | 0.822 |
| Hypertension | 20 (33.3) | 66 (40.5) | 0.356 |
| Ischemic heart disease | 4 (6.7) | 19 (11.7) | 0.331 |
| Heart failure | 1 (1.7) | 12 (7.4) | 0.193 |
| Arrhythmia | 4 (6.7) | 7 (4.3) | 0.492 |
| Diabetes mellitus | 5 (8.3) | 28 (17.2) | 0.136 |
| Osteoporosis | 17 (28.3) | 10 (6.1) | <0.001 |
| Aspirin sensitivity | 4 (6.7) | 4 (2.5) | 0.216 |
| Depression | 7 (11.7) | 17 (10.4) | 0.809 |
| Medication | |||
| ICS inhaler | 4 (6.7) | 5 (3.1) | 0.255 |
| ICS+LABA combination inhaler | 49 (81.7) | 125 (76.7) | 0.471 |
| LAMA inhaler | 18 (30.0) | 102 (62.6) | <0.001 |
| LABA inhaler | 3 (5.0) | 11 (6.7) | 0.764 |
| Triple therapy (LAMA+ICS+LABA) | 12 (20.0) | 76 (46.6) | <0.001 |
| Leukotriene receptor antagonist | 28 (46.7) | 44 (27.0) | 0.006 |
| Oral theophyllin | 14 (23.3) | 55 (33.7) | 0.145 |
| Oral steroid | 2 (3.3) | 16 (9.8) | 0.078 |
| Inhaler compliance >75% | 55 (91.7) | 154 (94.5) | 0.443 |
| Total systemic steroid/6 mo† | 241.3±582.0 | 101.6±254.3 | 0.077 |
Values are presented as mean±SD or number (%) unless otherwise indicated.
*The less-smoking group represents the patients group with a smoking history of less than 10 pack-years and the more-smoking group represents the patients group with a smoking history of equal or more than 10 pack-years. †The amount of total systemic steroid used for the last 6 months is described as the equivalent dose of prednisolone.
FEV1: forced expiratory volume in 1 second; FVC: forced vital capacity; ACT: Asthma Control Test; CAT: COPD Assessment Test; PHQ-9: Patient Health Questionnaire; ICS: inhaled corticosteroid; LABA: long acting β2 agonist; LAMA: long acting muscarinic antagonist.