Table 2

Asthma outcomes by GSAQ score tertile

GSAQ tertile
Variables, mean (SD)T1T2T3p Valuep Value*p Value†
ACQ, mean (SD)0.76 (0.78)0.99 (0.46)1.52 (0.82)0.007‡0.0250.090
Morning symptom0 (0, 0)0 (0, 1)1 (0, 2)0.007§
 Activity limitation0 (0, 1)1 (0, 1)2 (0, 3)0.069
 SABA use0 (0, 1)1 (1, 1)1 (0, 2)0.109
 Shortness of breath(0, 1)1 (1, 2)3 (1, 4)<0.001
 Wheezing0.5 (0, 1)1 (0, 1)2 (1, 3)0.001
 Awakening0 (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)0.0020.0170.038
 Getting as much done5 (4.5, 5)4.5 (4, 5)4 (4, 5)0.213§
 Nocturnal symptoms5 (5, 5)5 (4, 5)5 (3, 5)0.165
 Rate4.5 (4, 5)4 (4, 4)4 (3, 4)0.005
 SABA use5 (4, 5)3 (3, 4)4 (3, 4)0.007
 Shortness of breath4 (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)0.00040.0100.083
 PACQLQ, mean (SD)5.7 (1.2)5.3 (1.3)4.9 (1.0)0.0530.2000.239
Spirometry
 FVC per cent predicted, mean (SD)97.8 (8.9)92.7 (24.0)106.6 (14.5)0.140‡0.0410.066
 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)0.0030.0130.017
Z score0.34 (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‡0.3170.417
 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)0.4710.8430.955
 Impedance (cm H2O/L/s), mean (SD)9.0 (2.4)8.4 (2.3)6.7 (2.2)0.0070.0320.011
Resistance (cm H2O/L/s), mean (SD)
 R58.3 (2.1)7.7 (2.1)6.9 (3.0)0.084‡0.2690.141
R106.6 (1.5)6.2 (1.7)5.3 (1.5)0.0250.1170.037
 R155.8 (1.3)5.4 (1.6)5.0 (1.3)0.1150.4070.146
 R205.4 (1.4)4.9 (1.4)4.9 (1.4)0.3040.6580.363
 R255.3 (1.4)5.0 (1.3)4.7 (1.2)0.2080.5760.274
 R356.0 (1.6)5.5 (1.2)5.1 (1.1)0.0690.2400.131
Reactance (cm H2O/L/s)¶, mean (SD)
 X5−3.3 (1.7)−3.1 (1.1)−2.6 (1.8)0.209‡0.3040.253
X102.1 (1.3)1.9 (0.9)1.0 (0.9)0.0050.0130.013
X151.4 (0.9)1.3 (0.8)0.5 (0.8)0.0050.0170.011
X200.7 (0.6)0.5 (0.8)0.1 (0.7)0.0150.0660.027
 X250.2 (0.6)0.2 (0.7)0.5 (0.6)0.1120.3850.175
 X351.3 (0.6)1.4 (0.7)1.5 (0.7)0.368 0.8740.560
AX (cm H2O/L)**29.5 (17.6)27.5 (15.2)15.1 (14.9)0.0150.0420.020
F res (1/s)**24.4 (3.8)23.3 (5.3)19.4 (7.4)0.0140.0640.004
Airway reactivity
 BDR, no. (%)7 (39)7 (33)5 (29)0.553††
 FEV1 per cent change1413100.395‡
 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.