Association Between Patient Preference for Inhaler Medications and Asthma Outcomes

Figures & data

Figure 1 Study flow.

Figure 2 Definition of patient preference for inhalers.

Table 1 Patient Characteristics

	Matched Preference	Mismatched Preference	p-value
	n = 269	n = 82
Age (year)	59.2 ± 15.1	61.2 ± 15.2	0.294
≥65 years old, n (%)	110 (40.9)	38 (46.3)	0.382
Number of females/males	171/98	46/36	0.223
Body mass index (kg/m^2)	23.6 ± 3.8	23.5 ± 4.8	0.607
Patients with smoking history, n (%)	91 (33.8)	32 (39.0)	0.687
Use of inhaled corticosteroids, n (%)	269 (100)	82 (100)	1.000
Type of inhaler device DPI/pMDI	194/75	54/28	0.275
(DPI device: Elipta/Turbohaler/Accuhaler/Twisthaler, n)	(64/94/29/7)	(22/25/6/1)	0.604
Use of LABA, n (%)	219 (81.4)	63 (76.8)	0.361
Use of LAMA, n (%)	25 (9.2)	9 (11.0)	0.652
Use of regular oral corticosteroids, n (%)	10 (3.7)	11 (13.4)	0.003*
Use of any biologics, n (%)	4 (1.5)	2 (2.4)	0.560
GINA treatment step, n  1/2/3/4/5	0/19/98/128/24	0/10/23/34/15	0.033*
FEV1% of predicted^a	97.4 ± 20.7	96.5 ± 20.2	0.880
FeNO^b	33.7 ± 35.2	47.5 ± 56.9	0.202
Disease duration (year)	11.0 ± 12.0	10.9 ± 10.8	0.840
Number of types of controller inhaler medications ever used	2.06 ± 1.20	2.46 ± 1.26	0.004*
Adherence ≥75%, n (%)	246 (91.5)	66 (80.5)	0.006*
ACT score	22.9 ± 3.0	20.6 ± 4.6	<0.001*
Uncontrolled asthma (ACT≤19), n (%)	36 (13.4%)	25 (30.5%)	<0.001*
Exacerbation rate rate (/year)	0.38 ± 1.27	0.88 ± 1.73	0.003*

Notes: *P < 0.05, chi-square test, Fisher’s exact test, or Mann–Whitney U-test. ^an=253. ^bn=238. Values are mean ± SD unless otherwise indicated.

Abbreviations: DPI, dry powder inhaler; pMDI, pressurized metered dose inhaler; LABA, long-acting β-agonist; LAMA, long-acting muscarinic antagonist; GINA, global initiative for asthma; FEV₁, forced expiratory volume in 1 s; FeNO, fractional exhaled nitric oxide; ACT, asthma control test; SD, standard deviation.

Figure 3 Comparison of (A) prevalence of uncontrolled asthma and (B) exacerbation rate between patients of matched and mismatched groups. Error bars represent (A) 95% score confidence intervals and (B) 95% confidence intervals. *P<0.05.

Table 2 Univariate and Multivariate Linear and Logistic Regression Analyses for Uncontrolled Asthma, Exacerbation Rate, and Adherence

	ACT Score ≤19 (Versus ACT Score ≥20)			Exacerbation Rate (/Year)			Good Adherence (Versus Poor Adherence)
	Odds Ratio	95% CI	P-value	Regression Coefficient	95% CI	P-value	Odds Ratio	95% CI	P-value
Univariate analysis
Matched preference (versus Mismatched)	0.352	0.196–0.637	<0.001*	0.497	0.149–0.846	0.005*	2.593	1.278–5.162	0.009*
Age	1.000	0.982–1.019	0.999	0.009	−0.011–0.029	0.366	1.005	0.983–1.027	0.667
Male (versus female)	0.469	0.243–0.860	0.018	0.137	−0.169–0.443	0.379	1.913	0.900–4.064	0.053
Body mass index	1.031	0.964–1.100	0.371	0.016	−0.058–0.090	0.673	0.989	0.914–1.075	0.794
Smoking (pack-year)	1.012	1.001–1.023	0.027*	−0.001	−0.014–0.012	0.885	1.015	0.995–1.046	0.242
GINA treatment step	2.168	1.474–3.266	<0.001*	0.496	0.124–0.868	0.009*	1.021	0.668–1.551	0.924
DPI (versus pMDI)	0.687	0.386–1.244	0.212	−0.221	−0.548–0.105	0.183	2.031	1.029–4.008	0.041*
Multivariate analysis
Matched preference (versus Mismatched)	0.331	0.175–0.629	<0.001*	0.494	0.143–0.846	0.006*	3.007	1.457–6.208	0.003*
Age	0.993	0.973–1.013	0.492	0.008	−0.012–0.028	0.412	1.005	0.982–1.028	0.672
Male (versus female)	0.278	0.131–0.592	<0.001*	0.128	−0.190–0.447	0.429	1.955	0.840–4.549	0.107
Body mass index	1.023	0.954–1.097	0.518	0.008	−0.064–-0.082	0.819	1.000	0.920–1.087	1.000
Smoking (pack-year)	1.017	1.004–1.030	0.010*	−0.007	−0.021–0.007	0.315	1.009	0.986–1.034	0.377
GINA treatment step	2.125	1.418–3.279	<0.001*	0.498	0.123–0.872	0.009*	1.049	0.678–1.623	0.829
DPI (versus pMDI)	0.759	0.404–1.427	0.366	−0.280	−0.605–0.044	0.090	1.906	0.931–3.905	0.082

Note: *P < 0.05.

Abbreviations: ACT, asthma control test; GINA, global initiative for asthma; DPI, dry powder inhaler; pMDI, pressurized metered dose inhaler; CI, confidence interval.

Table 3 Univariate and Multivariate Logistic Regression Analyses for Regular Oral Corticosteroid

	Odds Ratio	95% CI	P-value
Univariate analysis
Matched preference (versus mismatched)	0.249	0.102–0.610	0.002*
Age	1.006	0.976–1.036	0.707
Male (versus female)	2.807	1.131–6.964	0.026*
Body mass index	0.948	0.843–1.065	0.353
Smoking (pack-year)	1.016	1.003–1.029	0.012*
DPI (versus pMDI)	1.352	0.482–3.792	0.567
Multivariate analysis
Matched preference (versus mismatched)	0.287	0.113–0.734	0.009*
Age	0.993	0.962–1.026	0.678
Male (versus female)	2.280	0.850–6.115	0.099
Body mass index	0.939	0.834–1.057	0.283
Smoking (pack-year)	1.011	0.995–1.027	0.177
DPI (versus pMDI)	1.502	0.517–4.363	0.443

Note: *P < 0.05.

Abbreviations: DPI, dry powder inhaler; pMDI, pressurized metered dose inhaler; CI, confidence interval.

Table 4 Comparison of Patient Characteristics Between Matched and Unmatched Groups Regarding DPI or pMDI Usage

	Patients Using DPI (n = 248)			Patients Using pMDI (n = 103)
	Matched Preference	Mismatched Preference	P-value	Matched Preference	Mismatched Preference	P-value
	n = 194	n = 54		n = 75	n = 28
Age (year)	58.1 ± 15.1	63.5 ± 14.0	0.020*	62.1 ± 14.8	56.8 ± 16.7	0.108
≥ 65 years old, n (%)	69 (35.6)	28 (51.9)	0.030*	41 (54.7)	10 (35.7)	0.087
Number of females/males	124/70	29/25	0.184	47/28	17/11	0.856
Body mass index (kg/m^2)	23.4 ± 3.8	24.0 ± 5.2	0.614	24.0 ± 4.0	22.6 ± 3.9	0.092
Patients with smoking history, n (%)	61 (31.4)	24 (44.4)	0.204	30 (40.0)	8 (28.6)	0.555
Use of LABA, n (%)	165 (85.1)	47 (87.0)	0.714	54 (72.0)	16 (57.1)	0.151
Use of LAMA, n (%)	17 (8.8)	7 (13.0)	0.356	8 (10.7)	2 (7.1)	0.591
Use of regular oral corticosteroids, n (%)	8 (4.1)	8 (14.8)	0.005*	2 (2.7)	3 (10.7)	0.114
Use of any biologics, n (%)	4 (2.1)	1 (1.9)	0.888	0 (0.0)	1 (3.6)	0.100
GINA treatment step, n  1/2/3/4/5	0/16/83/76/19	0/3/17/23/11	0.124	0/3/15/32/52/5	0/7/6/11/4	0.003*
Disease duration (year)	10.5 ± 10.7	11.3 ± 10.6	0.360	12.3 ± 14.5	9.9 ± 11.2	0.337
Exacerbation rate (/year)	0.88 ± 2.89	2.04 ± 3.78	<0.001*	0.49 ± 1.24	1.22 ± 2.69	0.648
ACT score	23.0 ± 2.8	20.9 ± 4.6	<0.001*	22.5 ± 3.3	20.1 ± 4.7	0.010*
Uncontrolled asthma (ACT≤ 19), n (%)	25 (12.9%)	14 (25.9%)	0.020*	11 (14.7%)	11 (39.3%)	0.007*
Adherence ≥75%, n (%)	180 (92.8)	46 (85.2)	0.511	66 (88.0)	20 (71.4)	0.044*

Note: *P < 0.05. Values are mean ± SD unless otherwise indicated.

Abbreviations: DPI, dry powder inhaler; pMDI, pressurized metered dose inhaler; LABA, long acting β-agonist; LAMA, long-acting muscarinic antagonist; GINA, global initiative for asthma; ACT, asthma control test; SD, standard deviation.