Table 2.
Asthma outcomes by GSAQ score tertile
| GSAQ tertile |
||||||
|---|---|---|---|---|---|---|
| Variables, mean (SD) | T1 | T2 | T3 | p Value | p Value* | p Value† |
| ACQ, mean (SD) | 0.76 (0.78) | 0.99 (0.46) | 1.52 (0.82) | 0.007 ‡ | 0.025 | 0.090 |
| Morning symptom | 0 (0, 0) | 0 (0, 1) | 1 (0, 2) | 0.007 § | ||
| Activity limitation | 0 (0, 1) | 1 (0, 1) | 2 (0, 3) | 0.069 | ||
| SABA use | 0 (0, 1) | 1 (1, 1) | 1 (0, 2) | 0.109 | ||
| Shortness of breath | (0, 1) | 1 (1, 2) | 3 (1, 4) | <0.001 | ||
| Wheezing | 0.5 (0, 1) | 1 (0, 1) | 2 (1, 3) | 0.001 | ||
| Awakening | 0 (0, 0) | 0 (0, 2) | 1 (0, 2) | 0.011 | ||
| ACT, mean (SD) | 23.0 (1.5) | 19.6 (2.9) | 18.8 (3.6) | 0.002 ‡ | 0.017 | 0.038 |
| Getting as much done | 5 (4.5, 5) | 4.5 (4, 5) | 4 (4, 5) | 0.213§ | ||
| Nocturnal symptoms | 5 (5, 5) | 5 (4, 5) | 5 (3, 5) | 0.165 | ||
| Rate | 4.5 (4, 5) | 4 (4, 4) | 4 (3, 4) | 0.005 | ||
| SABA use | 5 (4, 5) | 3 (3, 4) | 4 (3, 4) | 0.007 | ||
| Shortness of breath | 4 (4, 5) | 4 (3, 4) | 4 (3, 4) | 0.028 | ||
| Quality of Life | ||||||
| PAQLQ, mean (SD) | 5.9 (1.0) | 5.3 (1.2) | 4.4 (1.2) | 0.0004 ‡ | 0.010 | 0.083 |
| PACQLQ, mean (SD) | 5.7 (1.2) | 5.3 (1.3) | 4.9 (1.0) | 0.053 ‡ | 0.200 | 0.239 |
| Spirometry | ||||||
| FVC per cent predicted, mean (SD) | 97.8 (8.9) | 92.7 (24.0) | 106.6 (14.5) | 0.140‡ | 0.041 | 0.066 |
| Z score | −0.04 (0.49) | −0.32 (1.3) | 0.44 (0.80) | |||
| FEV1 per cent predicted, mean (SD) | 84.7 (13.1) | 86.7 (14.3) | 99.9 (16.3) | 0.003 ‡ | 0.013 | 0.017 |
| Z score | −0.34 (0.83) | −0.21 (0.91) | 0.62 (1.0) | |||
| FEV1 (litres)/FVC (litres) | 75.8 (12.3) | 77.9 (7.8) | 82.1 (8.9) | 0.060‡ | 0.317 | 0.417 |
| Z score | −0.27 (1.23) | −0.06 (0.78) | 0.37 (0.90) | |||
| FENO (ppb), mean (SD) | 59.9 (50.2) | 55.4 (58.0) | 43.4 (32.2) | 0.471 | 0.843 | 0.955 |
| Impedance (cm H2O/L/s), mean (SD) | 9.0 (2.4) | 8.4 (2.3) | 6.7 (2.2) | 0.007 | 0.032 | 0.011 |
| Resistance (cm H2O/L/s), mean (SD) | ||||||
| R5 | 8.3 (2.1) | 7.7 (2.1) | 6.9 (3.0) | 0.084‡ | 0.269 | 0.141 |
| R10 | 6.6 (1.5) | 6.2 (1.7) | 5.3 (1.5) | 0.025 | 0.117 | 0.037 |
| R15 | 5.8 (1.3) | 5.4 (1.6) | 5.0 (1.3) | 0.115 | 0.407 | 0.146 |
| R20 | 5.4 (1.4) | 4.9 (1.4) | 4.9 (1.4) | 0.304 | 0.658 | 0.363 |
| R25 | 5.3 (1.4) | 5.0 (1.3) | 4.7 (1.2) | 0.208 | 0.576 | 0.274 |
| R35 | 6.0 (1.6) | 5.5 (1.2) | 5.1 (1.1) | 0.069 | 0.240 | 0.131 |
| Reactance (cm H2O/L/s)¶, mean (SD) | ||||||
| X5 | −3.3 (1.7) | −3.1 (1.1) | −2.6 (1.8) | 0.209‡ | 0.304 | 0.253 |
| X10 | −2.1 (1.3) | −1.9 (0.9) | −1.0 (0.9) | 0.005 | 0.013 | 0.013 |
| X15 | −1.4 (0.9) | −1.3 (0.8) | −0.5 (0.8) | 0.005 | 0.017 | 0.011 |
| X20 | −0.7 (0.6) | −0.5 (0.8) | −0.1 (0.7) | 0.015 | 0.066 | 0.027 |
| X25 | 0.2 (0.6) | 0.2 (0.7) | 0.5 (0.6) | 0.112 | 0.385 | 0.175 |
| X35 | 1.3 (0.6) | 1.4 (0.7) | 1.5 (0.7) | 0.368 | 0.874 | 0.560 |
| AX (cm H2O/L) ** | 29.5 (17.6) | 27.5 (15.2) | 15.1 (14.9) | 0.015 ‡ | 0.042 | 0.020 |
| F res (1/s) ** | 24.4 (3.8) | 23.3 (5.3) | 19.4 (7.4) | 0.014 | 0.064 | 0.004 |
| Airway reactivity | ||||||
| BDR, no. (%) | 7 (39) | 7 (33) | 5 (29) | 0.553†† | ||
| FEV1 per cent change | 14 | 13 | 10 | 0.395‡ | ||
| PC20 (mg/mL) | 0.7 (0.3, 1.3) | 1.2 (0.4, 4.4) | 1.2 (0.2, 3.1) | 0.249§ | ||
p Value after adjustment for BMI percentile.
p Value after adjustment for BMI percentile, sex, second-hand tobacco smoke exposure and presence or depression or anxiety.
Analysis of variance test for linear trend.
Kruskal–Wallis test for subscales.
More negative numbers correspond to worse lung function.
Lower values correspond to worse lung function.
Cochran–Armitage Trend test for categorical variables.
ACQ, Asthma Control Questionnaire, subscales under ACQ are 0–6 point integer scales with a higher score indicating worse asthma; ACT, asthma control test, subscales under ACT are 1–5 point integer scales with a lower score indicating worse asthma; AX, area of reactance; BDR, bronchodilator reversibility (≥12% improvement in FEV1); F res, resonant frequency; GSAQ, GERD Symptoms Assessment Questionnaire; PACQLQ, paediatric asthma caregiver’s quality of life questionnaire; ppb, parts per billion; PAQLQ, paediatric asthma quality of life questionnaire; PC20, provocation concentration eliciting a 20% FEV1 drop; SABA, short-acting β agonist; R, resistance; X, reactance.
Bolded figures represent statistical significance at the level of p<0.05