Factors influencing asthma control: results of a real-life prospective observational asthma inhaler treatment (ASIT) study

Figures & data

Table 1 Sociodemographic characteristics of patients according to asthma control at baseline

	Overall (n = 572)	Asthma control status		P value
		Controlled (ACT ≥ 20, n = 352)	Uncontrolled (ACT < 20, n = 220)
	Mean (SD)
Age (year)	42.7 (12.2)	43.6 (12.1)	41.3 (12.2)	0.061
Age categories (year)	n (%)
18–40	252 (44.1)	144 (40.9)	108 (49.1)	0.055
41–60	272 (47.6)	175 (49.7)	97 (44.1)	0.192
>60	48 (8.4)	33 (9.4)	15 (6.8)	0.276
Gender	n (%)
Male	137 (24.0)	92 (26.1)	45 (20.5)	0.127
Female	435 (76.0)	260 (73.9)	175 (79.5)	0.127
	Mean (SD)
Time from asthma onset (years)	8.0 (8.3)	8.0 (8.3)	8.0 (8.2)	1.00
	n (%)
≤5	305 (53.3)	191 (54.3)	114 (51.8)	0.560
>5 to ≤ 10	118 (20.6)	68 (19.3)	50 (22.7)	0.328
> 10 to ≤15	59 (10.3)	36 (10.2)	23 (10.5)	0.909
>15	90 (15.7)	57 (16.2)	33 (15.0)	0.701
Comorbidities	n (%)
None	162 (28.3)	115 (32.7)	47 (21.4)	0.003
Non-asthma related	209 (36.5)	126 (35.8)	83 (37.7)	0.646
Asthma related	321 (56.1)	181 (51.4)	140 (63.6)	0.004
Rhinitis*	219 (68.2)	120 (66.3)	99 (70.7)	0.009
Sinusitis*	105 (32.7)	57 (31.5)	48 (34.3)	0.092
GERD*	106 (33.0)	59 (32.6)	47 (33.6)	0.169
Number of comorbidities	n (%)
1 comorbidity	218 (67.9)	109 (31)	109 (62.5)	<0.001
2 comorbidities	69 (21.5)	35 (9.9)	34 (15.5)	0.045
3 comorbidities	34 (10.6)	19 (5.4)	15 (6.8)	0.491
Active smoking	104 (18.2)	53 (15.1)	51 (23.2)	0.015
Educational status	n (%)
Illiterate	28 (4.9)	14 (4.0)	14 (6.4)	0.197
Secondary school	440 (76.9)	279 (79.3)	161 (73.2)	0.092
University	104 (18.2)	59 (16.8)	48 (21.8)	0.139
Employment status	n (%)
Unemployed	354 (61.9)	223 (63.4)	131 (59.5)	0.350
Employed	210 (36.7)	126 (35.8)	84 (38.2)	0.562
Missing	8	3	5

Note:

* Percent of patients with asthma-related comorbidities.

Abbreviation: ACT, asthma control test; n, number; SD, standard deviation.

Figure 1 Asthma control improvement between visits.

Note: *P < 0.001, compared to rate of controlled asthma at the same visit; ⁺P < 0.001 compared to visit 1.
Abbreviation: ACT, asthma control test.

Table 2 Change in asthma control status from Visit 1–Visit 4 in terms of asthma duration, BMI, smoking status, and comorbid disorders

	Asthma control status
	Controlled (ACT ≥ 20)			Uncontrolled (ACT < 20)
	Visit 1 n (%)	Visit 4 n (%)	P value*	Visit 1 n (%)	Visit 4 n (%)	P value*
All patients	352 (61.5)	269 (87.3)	<0.001	220 (38.5)	39 (12.7)	<0.001
Time from asthma onset (years)a
0–15 years (V1: n = 482; V4: n = 251)	294 (61.0)	215 (86.0)	<0.001	187 (39.0)	35 (14.0)	<0.001
≥15 years (V1: n = 90; V4: n = 57)	57 (63.0)	52 (91.0)	<0.001	33 (37.0)	4 (9.0)	<0.001
BMI (kg/m^2)b
≥30 (V1: n = 180; V4: n = 88)	107 (59.4)	72 (81.8)	0.0003	73 (40.6)	16 (18.2)	<0.001
<30 (V1: n = 363; V4: n = 131)	226 (62.3)	116 (88.5)	<0.001	137 (37.7)	15 (11.5)	<0.001
Smokingc
Smoker (V1: n = 104; V4: n = 50)	52 (51.0)	39 (78.0)	0.0014	51 (49.0)	11 (22.0)	0.001
Non-smoker (V1: n = 468; V4: n = 258)	300 (64.0)	230 (89.0)	<0.001	168 (36.0)	28 (11.0)	<0.001
Comorbid disorder #	ACT score				Pvalue**
	Visit 1 Mean (SD)		Visit 4 Mean (SD)
1 (V1: n = 218; V4: n = 117)	19.9 (4.4)		22.6 (3.3)		<0.001
2 (V1: n = 69; V4: n = 33)	19.3 (4.7)		22.0 (4.1)		0.004
3 (V1: n = 34; V4: n = 20)	16.9 (6.1)**		20.4 (4.6)		0.021

Notes:

* Versus visit 1.

** P = 0.007, compared to patients with 1 comorbid disorder. Comparison of asthma control rate:

a time from asthma onset of 0–15 years versus ≥15 years at visit 1: P = 0.692; and at visit 4: P = 0.1643.

b BMI of ≥30 kg/m² versus <30 kg/m² at visit 1: P = 0.526; and at visit 4: P = 0.009.

c smokers versus non-smokers at visit 1: P = 0.010; and at visit 4: P = 0.030.

Abbreviations: ACT, asthma control test; BMI, body mass index; n, number; SD, standard deviation; V, visits.

Figure 2 Change in percentage of uncontrolled asthma patients (n = 220) with fixed dose and seperate combination inhaler treatments from visit 1 to visit 4.

Abbreviations: FP/s, fluticasone propionate/salmeterol; BDP/F, beclomethasone/formoterol; B/F, budesonide/formoterol; B + F, budesonide + formoterol.

Table 3 Asthma control level according to inhaler device as assessed by the physicians

	Total (n = 572)	Visit 1 (Month 0)		Total (n = 308)	Visit 4 (Month 6)		P value*
		Asthma control status			Asthma control status
		Controlled (ACT ≥ 20, n = 352)	Uncontrolled (ACT < 20, n = 220)		Controlled (ACT ≥ 20, n = 269)	Uncontrolled (ACT < 20, n = 39)
According to inhaler types used
Fixed dose combinations	n (%)
FP/S Discus	152 (26.6)	94 (61.8)	58 (38.2)	79 (25.6)	70 (88.6)	9 (11.4)	<0.001
BDP/F Solution spray	107 (18.7)	72 (67.3)	35 (32.7)	60 (19.5)	54 (90.0)	6 (10.0)	<0.001
B/F Turbuhaler	156 (27.3)	91 (58.3)	65 (41.7)	87 (28.2)	74 (85.1)	13 (14.9)	<0.001
Separate combinations	n (%)
B + F Aerolizer	84 (14.7)	48 (57.1)	36 (42.9)	51 (16.6)	39 (76.5)	12 (23.5)	0.131
B + F Easyhaler**	21 (3.8)	14 (66.7)	7 (33.3)	8 (2.6)	8 (100.0)	0 (0.0)	**

Notes:

* Rate of uncontrolled asthma visit 1 versus visit 4.

** No statistical analysis was done because of small number of patients.

Abbreviations: ACT, asthma control test; B, budesonide; BDP, beclometasone dipropionate; F, formoterol; FP, fluticasone propionate; S, salmeterol; n,number.

Table 4 Logistic regression analysis for predictors of asthma control

	OR	95% CI	P value
Female	1.351	0.876; 2.085	0.173
Asthma related comorbidity present	0.602	0.419; 0.863	0.006
Asthma unrelated comorbidity present	0.926	0.624; 1.373	0.700
Smoking	0.522	0.330; 0.825	0.005
Patient age >60 years	1.456	0.735; 2.883	0.281
BMI ≥ 30 kg/m^2	0.926	0.628; 1.367	0.700
Disease duration ≥10 years	1.070	0.710; 1.612	0.748
Educated (literate)	0.533	0.229; 1.238	0.143

Abbreviations: BMI, body mass index; CI, confidence interval; OR, odds ratio.