The Relationship Between the “Adherence Starts with Knowledge-20” Questionnaire and Clinical Factors in Patients with COPD: A Multi-Center, Cross-Sectional Study

Figures & data

Table 1 Characteristics of the Included Studies

Characteristics		Total (n = 319)
Age, years		74 (68‒79)
Male, n (%)		278 (87%)
Total ASK-20 scores		38 (33‒44)
TBCs		3 (2‒5)
CAT		14 (8‒20.5)
mMRC		1 (1‒2)
HADS-anxiety		4 (3‒7)
HADS-depression		6 (3‒9)
Satisfaction		106 (33%)
Lung function tests	VC, L	3.1 ± 0.8
	%VC, %	96.1 (85.4‒107.8)
	FEV1, L	1.6 (1.1‒2.0)
	%FEV1, %pred	65.4 ± 22.4
GOLD stage	I	98 (31%)
	II	143 (45%)
	III	57 (18%)
	IV	21 (6%)
Living alone, n (%)		73 (23%)
Hypertension, n (%)		132 (44%)
Hyperlipidemia, n (%)		68 (23%)
Hyperuricemia, n (%)		45 (15%)
Atrial fibrillation, n (%)		18 (5.9%)
Diabetes, n (%)		54 (18%)
Inhaler therapy (single)		262 (82%)
Inhaler device (single) (n = 262)
	Ellipta/Respimat/Breezhaler	69 (26%)/97 (37%)/83 (32%)
	Aerosol/Genuair/Diskus	3 (1.1%)/6 (2.2%)/4 (1.5%)
Inhaler component total, n (%)	LAMA/LABA/ICS	277 (87%)/261 (82%)/77 (24%)
Inhaler component, n (%)	LAMA alone	58 (18%)
	LABA alone	22 (6.8%)
	ICS alone	0 (0%)
	LAMA/LABA combinations	163 (51%)
	LAMA/ICS combinations	0 (0%)
	ICS/LABA combinations	20 (6.2%)
	LAMA/LABA/ICS triplets	56 (18%)

Notes: Categorical variables are presented as number (%). Continuous variables are reported as mean (standard deviation ± SD) for normally distributed data and as median (interquartile range) for non-normally distributed data.

Abbreviations: ASK-20, Adherence Starts with Knowledge-20; CAT, the COPD Assessment Test; FEV1, forced expiratory volume in 1 second; %FEV1, % predicted forced expiratory volume in 1 second; GOLD, the Global Initiative for Chronic Obstructive Lung Disease; HADS, the Hospital Anxiety and Depression Scale; ICS, inhaled corticosteroid; LABA, long-acting β2 agonist; LAMA, long-acting muscarinic antagonist; mMRC, the modified Medical Research Council; TBCs, total barrier counts; VC, vital capacity; %VC, % predicted vital capacity.

Figure 1 Distribution of Adherence Starts with Knowledge-20 (ASK-20) score. The median total ASK-20 score was 38 (33–44). The x-axis shows the total ASK-20 scores and the y-axis shows the frequency.

Table 2 Relationship Between Comorbidities and Adherence Starts with Knowledge-20 (ASK-20) Score and Total Barrier Counts (TBCs)

Comorbidity	Total (n = 319)
	ASK-20 Score		TBCs
	Median (Interquartile Range)	p-value	Median (Interquartile Range)	p-value
Hypertension	39.5 (38.1–40.8)		3.8 (3.4–4.2)
No Hypertension	38.8 (37.5–40.1)	0.45	3.7 (3.3–4.1)	0.58
Hyperlipidemia	39.1 (37.2–41.0)		3.9 (3.4–4.6)
No Hyperlipidemia	39.1 (38.0–40.1)	0.86	3.7 (3.3–4.0)	0.28
Hyperuricemia	39.7 (37.3–42.1)		4.1 (3.3–4.8)
No Hyperuricemia	39.0 (38.0–40.0)	0.61	3.7 (3.4–4.0)	0.23
Atrial fibrillation	41.2 (37.0–45.5)		4.4 (3.1–5.7)
No Atrial fibrillation	39.0 (38.0–39.9)	0.28	3.7 (3.4–4.0)	0.16
Diabetes	40.6 (38.5–42.7)		4.1 (3.6–4.7)
No Diabetes	38.8 (37.7–39.8)	0.12	3.7 (3.3–4.0)	0.06

Note: Differences with a p-value of < 0.05 were considered statistically significant.

Abbreviations: ASK-20, Adherence Starts with Knowledge-20; TBCs, total barrier counts.

Figure 2 Correlation of total Adherence Starts with Knowledge-20 (ASK-20) score and total barrier counts (TBCs) with patients’ clinical factors and inhaler therapy. Correlation plot of age with ASK-20 score (A) and TBCs (B). Correlation plot of CAT score with ASK-20 score (C) and TBCs (D). Correlation plot of mMRC with ASK-20 score (E) and TBCs (F). Correlation plot of the HADS-anxiety score with the ASK-20 score (G) and TBCs (H). Correlation plot of the HADS-depression score with the ASK-20 score (I) and TBCs (J). Correlation plot of the %FEV1.0 with the ASK-20 score (K) and TBCs (L). The total ASK-20 scores and TBCs were significantly correlated with the CAT, HADS-anxiety, and HADS-depression scores.

Abbreviations: ASK-20, Adherence Starts with Knowledge-20; CAT, the COPD Assessment Test; %FEV1, % predicted forced expiratory volume in 1 second; HADS, the Hospital Anxiety and Depression Scale; mMRC, the modified Medical Research Council; TBCs, total barrier counts.

Table 3 Multivariable Analysis of Factors Associated with the Adherence Starts with Knowledge-20 (ASK-20) Score

Clinical Factor	Standard	β, Standardized	95% Confidence Interval		p
	Error	Coefficient	Lower	Upper
Age, years	0.06	0.01	−0.11	0.13	0.86
Male, n (%)	0.08	−0.04	−0.23	0.10	0.44
CAT	0.08	0.18	0.03	0.35	0.02
mMRC	0.08	−0.05	−0.21	0.10	0.51
%FEV1, %pred	0.07	0.08	−0.05	0.21	0.24
HADS-anxiety	0.06	0.29	0.17	0.42	<0.01
Satisfaction	0.06	−0.09	−0.04	0.21	0.17
Diabetes	0.07	−0.05	−0.20	0.09	0.42

Abbreviations: CAT, the COPD Assessment Test; %FEV1, % predicted forced expiratory volume in 1 second; HADS, the Hospital Anxiety and Depression Scale; mMRC, the modified Medical Research Council.

Table 4 Relationship Between Inhaler Devices and Clinical Factors

		Total (n = 249)
		Ellipta (n = 69)	Respimat (n = 97)	Breezhaler (n = 83)	p-value	Ellipta/Respimat	Ellipta/Breezhaler	Respimat/Breezhaler
Age, years		74 (72‒76)	72 (70‒74)	75 (73‒76)	0.1	0.2	0.64	0.03
Male, n (%)		57 (83%)	84 (87%)	72 (87%)	0.72
CAT		15.8 (14‒17.7)	12.9 (11.4‒14.4)	14.2 (12.5‒15.9)	0.048	0.02	0.17	0.25
mMRC		1.5 (1.3‒1.8)	1.2 (1.0‒1.4)	1.3 (1.1‒1.5)	0.21	0.08	0.24	0.6
HADS-anxiety		4.8 (4‒5.6)	4.7 (4.0‒5.4)	4.9 (4.0‒5.7)	0.97	0.81	0.9	0.9
HADS-depression		5.4 (4.7‒6.3)	6.3 (5.6‒7.0)	5.8 (5.0‒6.6)	0.34	0.17	0.7	0.3
Satisfaction		20 (29%)	34 (35%)	27 (33%)	0.69
VC, L		3.2 ± 0.8	3.2 ± 0.8	3.1 ± 0.8	0.74	0.93	0.59	0.45
%VC, %		99.6 (94.7‒104.6)	92.8 (88.6‒96.9)	95.4 (91.1‒99.7)	0.11	0.04	0.16	0.53
FEV1, L		1.7 (1.5‒1.9)	1.7 (1.6‒1.8)	1.7 (1.5‒1.8)	0.97	0.83	0.83	1
%FEV1, %pred		69.7 ± 25.4	64.0 ± 20.1	68.1 ± 20.3	0.4	0.27	0.78	0.24
Inhaler component
LAMA alone	LAMA alone	12 (17%)	37 (38%)	3 (3.6%)	<0.01
LABA alone	LABA alone	0 (0%)	0 (0%)	21 (25%)	<0.01
LAMA/LABA combinations	LAMA/LABA combinations	42 (61%)	60 (62%)	59 (71%)	0.32
ICS/LABA combinations	ICS/LABA combinations	13 (19%)	0 (0%)	0 (0%)	<0.01
LAMA/LABA/ICS triplets	LAMA/LABA/ICS triplets	2 (2.9%)	0 (0%)	0 (0%)	0.072
living alone		18 (26%)	23 (24%)	23 (28%)	0.83
ASK-20 questionnaire
Total ASK-20 scores		39.8 (37.9‒41.8)	38.5 (37‒40.1)	39.2 (37.3‒41)	0.64	0.39	0.43	0.91
Lifestyle	Lifestyle	11.7 (11.1‒12.5)	11.7 (11.2‒12.3)	11.6 (10.9‒12.3)	0.78	0.83	0.67	0.48
Attitude and beliefs toward your treatment	Attitude and beliefs toward your treatment	4.6 (4.3‒5.1)	4.9 (4.6‒5.2)	5.0 (4.6‒5.4)	0.62	0.44	0.36	0.89
Help from others	Help from others	2.8 (2.4‒3.1)	2.8 (2.5‒3.0)	2.9 (2.6‒3.2)	0.81	0.99	0.59	0.57
Talking with healthcare team	Talking with healthcare team	6.6 (6.1‒7.3)	6.3 (5.9‒6.8)	6.4 (5.9‒7.0)	0.51	0.25	0.53	0.55
Taking medicines	Taking medicines	6.8 (6.1‒7.5)	6.2 (5.6‒6.8)	6.6 (6.1‒7.2)	0.28	0.15	0.67	0.23
Have you …	Have you …	7 (6.4‒7.8)	6.8 (6.1‒7.2)	6.6 (6.0‒7.2)	0.42	0.34	0.21	0.67
TBCs		4.1 (3.5‒4.7)	3.6 (3.1‒4.0)	3.7 (3.1‒4.3)	0.36	0.2	0.22	0.92

Note: Differences of p < 0.05 were considered statistically significant.

Abbreviations: ASK-20, Adherence Starts with Knowledge-20; CAT, the COPD Assessment Test; FEV1, forced expiratory volume in 1 second; %FEV1, % predicted forced expiratory volume in 1 second; HADS, the Hospital Anxiety and Depression Scale; ICS, inhaled corticosteroid; LABA, long-acting β2 agonist; LAMA, long-acting muscarinic antagonist; mMRC, the modified Medical Research Council; TBCs, total barrier counts; VC, vital capacity; %VC, % predicted vital capacity.

Table 5 Differences in Clinical Factors Between Patients Treated with Single or Multiple Maintenance Inhalers

	Total (n = 319)
	Single Inhaler (n = 262)	Multiple Inhalers (n = 57)	p-value
Age, years	73 (72‒74)	74 (72‒76)	0.79
Male, n (%)	224 (86%)	54 (95%)	0.06
CAT	14.2 (13.3‒15.1)	15.7 (13.4‒18)	0.23
mMRC	1.3 (1.2‒1.5)	1.4 (1.1‒1.7)	0.65
HADS-anxiety	4.9 (4.4‒5.3)	5.0 (4.1‒5.9)	0.65
HADS-depression	6.0 (5.6‒6.4)	6.6 (5.6‒7.6)	0.41
Satisfaction	86 (33%)	20 (35%)	0.77
Lung function tests
VC, L	3.1 ± 0.81	3.3 ± 0.87	0.2
%VC, %	95.2 (92.8‒97.7)	97.7 (92‒103.3)	0.57
FEV1, L	1.6 (1.6‒1.7)	1.6 (1.4‒1.8)	0.3
%FEV1, %pred	66.5 ± 21.6	60.8 ± 25.2	0.13
Inhaler component
LAMA alone	58 (22%)	0 (0%)	<0.01
LABA alone	22 (8.4%)	0 (0%)	0.03
LAMA/LABA combinations	161 (61%)	2 (3.5%)	<0.01
ICS/LABA combinations	19 (7.3%)	1 (1.7%)	0.12
LAMA/LABA/ICS triplets	2 (0.8%)	54 (95%)	<0.01
Living alone	67 (26%)	6 (11%)	0.01
ASK-20 questionnaire
Total ASK-20 scores	39.3 (38.3‒40.3)	37.6 (35.4‒39.8)	0.11
Lifestyle	11.7 (11.4‒12.1)	11.6 (11‒12.2)	0.8
Attitude and beliefs toward your treatment	4.9 (4.7‒5.1)	4.6 (4.3‒5.0)	0.24
Help from others	2.8 (2.7‒3.0)	2.5 (2.2‒2.9)	0.15
Talking with healthcare team	6.5 (6.2‒6.8)	6.2 (5.5‒6.8)	0.36
Taking medicines	6.5 (6.2‒6.9)	6.2 (5.5‒6.9)	0.38
Have you …	6.8 (6.5‒7.2)	6.4 (5.7‒7.1)	0.2
TBCs	3.9 (3.5‒4.2)	3.3 (2.6‒4.0)	0.055

Note: Differences of p < 0.05 were considered statistically significant.

Abbreviations: ASK-20, Adherence Starts with Knowledge-20; CAT, the COPD Assessment Test; FEV1, forced expiratory volume in 1 second; %FEV1, % predicted forced expiratory volume in 1 second; HADS, the Hospital Anxiety and Depression Scale; ICS, inhaled corticosteroid; LABA, long-acting β2 agonist; LAMA, long-acting muscarinic antagonist; mMRC, the modified Medical Research Council; TBCs, total barrier counts; VC, vital capacity; %VC, % predicted vital capacity.