Clinical characteristics and burden of illness among adolescent and adult patients with severe asthma by asthma control: the IDEAL study

Figures & data

Figure 1. Patient disposition.

Table 1. Demographic characteristics and comorbidities of patients with severe asthma by asthma control.

Characteristic	Controlled N = 130	Uncontrolled N = 540	Total Cohort N = 670
Age, years, mean (SD)	50.9 (14.8)	50.4 (15.8)	50.5 (15.6)
Female, n (%)	75 (58)	340 (63)	415 (62)
BMI, kg/m^2, mean (SD)	28.5 (6.4)	30.2 (7.6)	29.9 (7.4)
Smoking status, n (%)
Current	9 (7)	43 (8)	52 (8)
Previous	37 (29)	153 (28)	190 (28)
Never	84 (65)	344 (64)	428 (64)
Current medical conditions, n (%)
Allergic rhinitis or hay fever	92 (71)	351 (65)	443 (66)
Obesity	45 (35)	222 (41)	267 (40)
Gastroesophageal reflux disease	45 (35)	197 (37)	242 (36)
Anxiety	24 (19)	104 (19)	128 (19)
Depression	15 (12)	87 (16)	102 (15)
Eczema	27 (21)	58 (11)	85 (13)
Sinusitis	22 (17)	64 (12)	86 (13)
Diabetes mellitus	12 (9)	70 (13)	82 (12)
Aspirin sensitivity	13 (10)	53 (10)	66 (10)
Nasal polyps	18 (14)	55 (10)	73 (11)
Osteoporosis	8 (6)	62 (12)	70 (10)
COPD	2 (2)	31 (6)	34 (5)

BMI, body mass index; COPD, chronic obstructive pulmonary disease; SD, standard deviation.

Table 2. Clinical characteristics and patient-reported outcomes of patients with severe asthma by asthma control.

Characteristic	Controlled N = 130	Uncontrolled N = 540	Total Cohort N = 670
Lung function
Pre-bronchodilator FEV1 % predicted, mean (SD)	75.6 (19.8)	67.1 (21.0)	68.7 (21.0)
Airway reversibility ≥12%, n (%)	40 (31)	228 (42)	268 (40)
Number of clinically significant exacerbations per patient in the previous 12 months, n (%)
≥1 event	0	382 (71)	382 (57)
1 event	0	185 (34)	185 (28)
2 events	0	92 (17)	92 (14)
3 events	0	53 (10)	53 (8)
>3 events	0	52 (10)	52 (8)
Events/patient-year, mean (SD)	0 (0.0)	1.5 (1.6)	1.2 (1.6)
Number of asthma exacerbations requiring hospitalization per patient in the previous 12 months, n (%)
≥1 event	0	58 (11)	58 (9)
≥2 events	0	20 (4)	20 (3)
Asthma medications use, n (%)
Current OCS use	6 (5)	88 (16)	94 (14)
Current omalizumab use	34 (26)	134 (25)	168 (25)
Blood eosinophil count at study visit, cells/µL
≥150, n (%)	90 (69)	335 (62)	425 (63)
≥300, n (%)	36 (28)	178 (33)	214 (32)
≥400, n (%)	18 (14)	121 (22)	139 (21)
Geometric mean (SD logs)	189 (0.815)	185 (1.041)	186 (1.001)
Total serum IgE, KU/L, geometric mean (SD logs)	177 (1.8)	150 (1.5)	155 (1.6)

FEV₁, forced expiratory volume in 1 s; IgE, immunoglobulin E; OCS, oral corticosteroid; SD, standard deviation.

Figure 2. Mean (a) SGRQ, (b) AQLQ, (c) ACQ-5, and (d) WPAI-GH scores in patients with severe asthma by asthma control.

ACQ, Asthma Control Questionnaire; AQLQ, Asthma Quality of Life Questionnaire; SGRQ, St George's Respiratory Questionnaire; WPAI-GH, Work Productivity and Activity Impairment Questionnaire: General Health.

Table 3. Demographic characteristics of patients with uncontrolled severe asthma by history of clinically significant exacerbations.

	Uncontrolled severe asthma (N = 540)
	No/infrequent (0–1) clinically significant exacerbations	Frequent (≥2) clinically significant exacerbations
Characteristic	n = 343 (63.5%)	n = 197 (36.5%)
Age, years, mean (SD)	51.9 (16.0)	47.8 (15.0)
Female, n (%)	211 (62)	129 (66)
BMI, kg/m^2, mean (SD)	30.1 (7.4)	30.5 (7.9)
Smoking status, n (%)
Current	32 (9)	11 (6)
Previous	88 (26)	65 (33)
Never	223 (65)	121 (61)
Current medical conditions, n (%)
Allergic rhinitis or hay fever	219 (64)	132 (67)
Obesity	138 (40)	84 (43)
Gastroesophageal reflux disease	123 (36)	74 (38)
Anxiety	64 (19)	40 (20)
Depression	55 (16)	32 (16)
Eczema	34 (10)	24 (12)
Sinusitis	30 (9)	34 (17)
Diabetes mellitus	52 (15)	18 (9)
Aspirin sensitivity	36 (11)	17 (9)
Nasal polyps	27 (8)	28 (14)
Osteoporosis	33 (10)	29 (15)
COPD	15 (4)	16 (8)

BMI, body mass index; COPD, chronic obstructive pulmonary disease; SD, standard deviation.

Table 4. Clinical characteristics and patient-reported outcomes of patients with uncontrolled severe asthma by history of clinically significant exacerbations.

	Uncontrolled severe asthma (N = 540)
	None/infrequent (0–1) clinically significant exacerbations	Frequent (≥2) clinically significant exacerbations
Characteristic	n = 343 (63.5%)	n = 197 (36.5%)
Lung function
Pre-bronchodilator FEV1 % predicted, mean (SD)	68.4 (20.4)	64.8 (21.7)
Airway reversibility ≥12%, n (%)	136 (39.7)	92 (46.7)
Number of clinically significant exacerbations per patient in the previous 12 months, n (%)
0 event	158 (46)	0
≥1 event	185 (54)	197 (100)
1 event	185 (54)	0
2 events	0	92 (47)
3 events	0	53 (27)
>3 events	0	52 (26)
Events/patient-year, mean (SD)	0.5 (0.5)	3.1 (1.6)
Number of asthma exacerbations requiring hospitalization per patient in the previous 12 months, n (%)
≥1 event	16 (5)	42 (21)
≥2 events	0	20 (10)
Asthma medications use, n (%)
Current OCS use	50 (15)	38 (19)
Current omalizumab use	83 (24)	51 (26)
Blood eosinophil count at study visit, cells/µL
≥150, n (%)	210 (61)	125 (64)
≥400, n (%)	75 (22)	46 (23)
Geometric mean (SD logs)	184 (1.048)	186 (1.033)
Total serum IgE, KU/L, geometric mean (SD logs)	156 (1.5)	141 (1.6)
Total neutrophil count (39), 10^9
<6.0, n (%)	245 (72)	122 (62)
6.0–<9.0, n (%)	72 (21)	45 (23)
≥9.0, n (%)	24 (7)	29 (15)
Health-related questionnaires, mean (SD)
SGRQ total score	45.1 (18.3)	50.3 (18.8)
SGRQ symptom domain score	56.4 (21.8)	63.0 (22.8)
SGRQ activity domain score	56.9 (23.5)	60.9 (22.5)
SGRQ impacts domain score	34.7 (19.3)	40.5 (20.2)
AQLQ total score	4.4 (1.2)	4.2 (1.3)
ACQ-5 score	2.3 (1.1)	2.5 (1.3)

ACQ, Asthma Control Questionnaire; AQLQ, Asthma Quality of Life Questionnaire; FEV₁, forced expiratory volume in 1 s; IgE, immunoglobulin E; OCS, oral corticosteroid; SD, standard deviation; SGRQ, St George's Respiratory Questionnaire.

Data sharing

Anonymized individual participant data and study documents for the original IDEAL study can be requested for further research from www.clinicalstudydatarequest.com.