Table 5.
The effect of bronchodilator treatment in patients with versus without SAD.
| SAD ( +) (N = 50) | SAD (−) (N = 13) | |||||||
|---|---|---|---|---|---|---|---|---|
| BD Rx (−) (N = 18) | BD Rx ( +) (N = 32) | p value | BD Rx (−) (N = 7) | BD Rx ( +) (N = 6) | p value | |||
| FVC (% predicted value) | 75.00 (64.00 to 82.50) | 62.00 (55.75 to 73.00) | 0.03 | 80.00 (77.00 to 93.50) | 89.00 (68.75 to 92.00) | 1.00 | ||
| FEV1 (% predicted value) | 96.50 (75.75 to 107.25) | 76.50 (66.75 to 83.75) | 0.04 | 102.00 (88.00 to 106.50) | 101.00 (86.00 to 120.50) | 0.94 | ||
| FEF25–75% (% predicted value) | 89.50 (68.50 to 130.00) | 89.00 (66.00 to 111.75) | 0.63 | 93.00 (84.00 to 102.50) | 94.00 (63.50 to 205.50) | 0.83 | ||
| FEV1/FVC % | 86.50 (80.50 to 90.00) | 86.00 (82.75 to 92.50) | 0.61 | 85.00 (82.00 to 87.50) | 85.50 (71.75 to 91.75) | 0.89 | ||
| DLCO (% predicted value) | 35.50 (26.50 to 47.50) | 32.50 (26.00 to 40.00) | 0.44 | 50.00 (31.50 to 59.50) | 29.00 (17.00 to 47.75) | 0.43 | ||
| R5–R20 (kPa L(− 1)sec) | 0.09 (0.08 to 0.12) | 0.09 (0.07 to 0.14) | 1.00 | 0.06 (0.06 to 0.07) | 0.06 (0.04 to 0.07) | 0.66 | ||
| X5 (kPa L(− 1)sec) | − 0.17 (− 0.21 to − 0.15) | − 0.16 (− 0.22 to − 0.14) | 0.56 | − 0.11 (− 0.12 to − 0.08) | − 0.11 (− 0.12 to − 0.10) | 1.00 | ||
| AX (kPa L(− 1)) | 1.02 (0.69 to 1.35) | 0.73 (0.61 to 1.20) | 0.56 | 0.41 (0.38 to 0.41) | 0.40 (0.34 to 0.42) | 0.94 | ||
| Fres (Hz) | 16.83 (15.68 to 18.18) | 16.47 (15.81 to 19.09) | 0.98 | 13.99 (13.82 to 14.18) | 14.46 (14.18 to 14.69) | 0.23 | ||
| CAT score | 5.00 (3.00 to 7.25) | 9.00 (4.00 to 12.00) | 0.04 | 5.00 (2.50 to 6.50) | 9.00 (5.00 to 9.00) | 0.61 | ||
| SGRQ | 18.78 (15.97 to 23.89) | 24.95 (17.47 to 50.80) | 0.11 | 16.44 (11.36 to 20.00) | 31.73 (22.12 to 36.62) | 0.07 | ||
| Symptom domain | 30.25 (13.98 to 36.34) | 30.17 (20.91 to 39.23) | 0.88 | 38.13 (27.28 to 44.25) | 38.30 (27.71 to 40.17) | 1.00 | ||
| Activity domain | 35.25 (17.14 to 53.20) | 47.84 (28.91 to 73.04) | 0.10 | 17.14 (8.20 to 32.31) | 53.62 (53.16 to 59.46) | 0.02 | ||
| Impact domain | 8.24 (2.20 to 14.93) | 10.86 (4.60 to 39.24) | 0.13 | 4.16 (3.86 to 8.76) | 6.36 (4.06 to 25.12) | 0.74 | ||
| △FVC (L) | − 0.09 (− 0.20 to 0.01) | 0.04 (− 0.11 to 0.14) | 0.06 | 0.03 (− 0.13 to 0.10) | − 0.06 (− 0.10 to 0.05) | 0.88 | ||
| △FEV1 (L) | − 0.05 (− 0.20 to 0.00) | 0.02 (− 0.04 to 0.11) | 0.01 | 0.07 (− 0.01 to 0.21) | 0.03 (− 0.05 to 0.05) | 0.32 | ||
| △FEF25–75% (L/s) | − 0.35 (− 0.52 to 0.11) | 0.11 (− 0.34 to 0.50) | 0.02 | 1.03 (0.27 to 1.40) | − 0.09 (− 0.34 to 0.32) | 0.06 | ||
| △DLCO (% predicted value) | − 4.50 (− 10.25 to 0.00) | − 0.50 (− 9.00 to 2.00) | 0.33 | − 6.00 (− 10.00 to − 0.50) | 8.00 (1.50 to 10.75) | 0.10 | ||
| △R5–R20 (kPa L(− 1)sec) | 0.02 (− 0.01 to 0.04) | 0.00 (− 0.03 to 0.03) | 0.10 | 0.00 (− 0.01 to 0.03) | 0.01 (− 0.01 to 0.03) | 0.95 | ||
| △X5 (kPa L(− 1)sec) | − 0.01 (− 0.03 to 0.02) | 0.00 (− 0.04 to 0.03) | 0.81 | − 0.03 (− 0.06 to 0.00) | − 0.03 (− 0.04 to 0.01) | 0.62 | ||
| △AX (kPa L(− 1)) | 0.08 (− 0.07 to 0.29) | 0.03 (− 0.21 to 0.18) | 0.63 | 0.07 (− 0.05 to 0.22) | 0.11 (0.05 to 0.20) | 0.63 | ||
| △Fres (Hz) | − 0.13 (− 0.92 to 1.75) | − 0.17 (− 1.36 to 1.50) | 0.85 | 0.93 (0.12 to 1.65) | 1.29 (0.48 to 2.11) | 0.84 | ||
| △CAT score | 1.00 (− 1.25 to 5.25) | − 3.00 (− 7.00 to − 1.00) | 0.01 | 1.00 (− 2.00 to 2.50) | 4.50 (1.75 to 6.25) | 0.22 | ||
| △SGRQ | 4.61 (− 4.26 to 12.31) | − 1.28 (− 11.70 to 6.37) | 0.15 | − 1.14 (− 6.14 to 2.10) | − 1.55 (− 6.63 to 3.86) | 0.65 | ||
| △Symptom domain | − 0.21 (− 4.18 to 2.85) | − 5.33 (− 16.46 to 11.03) | 0.77 | − 14.54 (− 23.89 to − 5.16) | 3.05 (− 7.91 to 15.56) | 0.11 | ||
| △Activity domain | 13.28 (− 2.23 to 32.38) | 0.32 (− 12.36 to 11.83) | 0.07 | 0.00 (− 14.54 to 14.44) | − 2.92 (− 9.30 to 1.46) | 0.57 | ||
| △Impact domain | 2.06 (− 4.47 to 6.83) | − 1.67 (− 13.64 to 5.46) | 0.32 | 0.00 (− 2.81 to 4.85) | 4.40 (− 3.33 to 8.71) | 0.78 | ||
Small airway dysfunction (SAD) is defined as AX > 0.44 (kPa/L) measured by impulse oscillometry. The data are described as median (interquartile range, IQR) for non-normally distributed variables. p values were generated from the Mann–Whitney U test for two-group comparisons.
BD Rx bronchodilator treatment, FVC forced vital capacity, FEV1 forced expiratory volume in the 1st second, FEF25–75% forced expiratory flow after expiration of 25% to 75% of forced vital capacity, DLCO diffusing capacity for carbon monoxide, R5 resistance at 5 Hz, R20 resistance at 20 Hz, X5 reactance at 5 Hz, Fres resonant frequency, AX area of reactance, CAT COPD assessment test, SGRQ St. George Respiratory Questionnaire, △ difference between visit 1 and visit 2.