Table 1.
Patient Baseline Demographics and Clinical Characteristics at Enrollment by PIF
| All Patients (N=403) | Suboptimal PIF (N=184) | Optimal PIF (N=219) | P-value | |
|---|---|---|---|---|
| Age, years, mean ± SD | 66.9 ± 9.3 | 66.7 ± 10.3 | 67.1 ± 8.3 | 0.679 |
| Female, N (%) | 159 (39.5) | 83 (45.1%) | 76 (34.7%) | 0.033 |
| Race, N (%) | <0.001 | |||
| White | 326 (80.9%) | 133 (72.3%) | 193 (88.1%) | |
| Black | 74 (18.4%) | 50 (27.2%) | 24 (11.0%) | |
| Other/missing | 3 (0.7%) | 1 (0.5%) | 2 (1.0%) | |
| Height, inches, mean ± SD | 67.2 ± 4.1 | 66.6 ± 4.1 | 67.8 ± 3.8 | 0.002 |
| Weight, pounds, mean ± SD | 194.2 ± 57.1 | 192.5 ± 58.6 | 195.6 ± 57.1 | 0.591 |
| BMI, kg/m2, mean ± SD | 30.2 ± 8.6 | 30.5 ± 8.6 | 29.9 ± 8.6 | 0.538 |
| Smoking status, N (%) | 0.571 | |||
| Never | 25 (6.2%) | 9 (4.9%) | 16 (7.3%) | |
| Current | 120 (29.8%) | 54 (29.3%) | 66 (30.1%) | |
| Former | 258 (64.0%) | 121 (65.8%) | 137 (62.6%) | |
| Months since COPD diagnosis, mean ± SD | 96.3 ± 80.4 | 104.2 ± 77.7 | 89.7 ± 82.1 | 0.072 |
| Enrollment timing, N (%) | ||||
| May – June 2019 | 61 (15.1%) | 28 (15.2%) | 33 (15.1%) | 0.967 |
| July – September 2019 | 160 (39.7%) | 47 (25.5%) | 113 (51.6%) | <0.001 |
| October – December 2019 | 93 (23.1%) | 23 (12.5%) | 70 (32.0%) | <0.001 |
| January – March 2020 | 89 (22.1%) | 86 (46.7%) | 3 (1.4%) | <0.001 |
| Highest PIF, L/min, mean ± SD | 64.4 ± 20.1 | 46.4 ± 9.3 | 79.4 ± 13.2 | <0.001 |
| PIF measurements, mean ± SD | 4.0 ± 1.2 | 3.7 ± 1.0 | 4.3 ± 1.4 | <0.001 |
| Micro-spirometry measurement, mean ± SD | ||||
| FEV1, L | 1.3 ± 0.5 | 1.2 ± 0.5 | 1.4 ± 0.5 | <0.001 |
| FEV1, % predicted | 46.8 ± 16.3 | 44.3 ± 16.0 | 48.9 ± 16.2 | 0.004 |
| FVC, L | 2.3 ± 0.9 | 2.1 ± 0.9 | 2.5 ± 0.8 | <0.001 |
| FEV1/FVC | 60.8 ± 17.0 | 61.8 ± 17.6 | 59.9 ± 16.5 | 0.280 |
| PEF, L/sec | 3.2 ± 1.7 | 2.6 ± 1.2 | 3.7 ± 1.8 | <0.001 |
| COPD moderate/severe exacerbations during 12-months prior to enrollment, mean ± SD | ||||
| All COPD exacerbations | 1.8 ± 1.2 | 1.9 ± 1.4 | 1.8 ± 1.3 | 0.370 |
| COPD exacerbations with hospitalization | 1.6 ± 1.1 | 1.6 ± 1.3 | 1.6 ± 1.0 | 0.586 |
| CAT total score, mean ± SD | 20.5 ± 7.5 | 22.3 ± 7.7 | 19.0 ± 7.0 | <0.001 |
| mMRC total score, mean ± SD | 1.8 ± 1.1 | 2.0 ± 1.1 | 1.7 ± 1.1 | 0.003 |
| Medication delivery at enrollment, N (%) | ||||
| Any DPI | 169 (44.2%) | 76 (44.4%) | 93 (44.1%) | nr |
| Any SMI | 123 (32.2%) | 55 (31.8%) | 68 (32.5%) | nr |
| Any MDI | 354 (92.7%) | 160 (93.6%) | 194 (91.9%) | nr |
| Any Nebulizer | 231 (57.3%) | 103 (56.0%) | 128 (58.4%) | nr |
| None | 17 (4.2%) | 7 (3.8%) | 10 (4.6%) | nr |
| Medication class at enrollment, N (%) | ||||
| Any SABD (includes SABA, SAMA, SAMA/SABA) | 362 (89.8%) | 164 (89.1%) | 198 (90.4%) | nr |
| Any LABD (includes LABA, LAMA, LABA/LAMA, LABA/ICS, LAMA/LABA/ICS) | 294 (73.0%) | 133 (72.3%) | 161 (73.5%) | nr |
| Antibiotics | 23 (5.7%) | 11 (6.0%) | 12 (5.5%) | nr |
| Methylxanthines | 21 (5.2%) | 10 (5.4%) | 11 (5.0%) | nr |
| Oral corticosteroids (OCS) | 19 (4.7%) | 8 (4.3%) | 11 (5.0%) | nr |
| Inhaled corticosteroids (ICS) | 15 (3.7%) | 6 (3.3%) | 9 (4.1%) | nr |
| Phosphodiesterase (PDE)-4 inhibitors | 22 (5.5%) | 6 (3.3%) | 16 (7.3%) | nr |
| None | 17 (4.2%) | 7 (3.8%) | 10 (4.6%) | nr |
Notes: PIF is against medium low resistance. Three patients did not complete the CAT symptoms assessment including 1 from the suboptimal PIF cohort and 2 from the optimal PIF cohort.
Abbreviations: COPD, chronic obstructive pulmonary disease; CAT, COPD Assessment Test; DPI, dry powder inhaler; FEV1, forced expiratory volume in one second; FVC, forced vital capacity; LABA, long-acting beta2-agonist; LABD, long-acting bronchodilator drug; LAMA, long-acting antimuscarinic antagonists; MDI, metered dose inhaler; mMRC, modified Medical Research Council; N, sample size; nr, not reported; PEF, peak expiratory flow; PIF, peak inspiratory flow; SABA, short-acting beta2-agonist; SAMA, short-acting antimuscarinic antagonists; SD, standard deviation; SMI, soft mist inhaler.