Evaluating inhaler use technique in COPD patients

Figures & data

Table 1 Demographic and clinical characteristics of COPD patients

Characteristics	n=103
Age (years)	71.2±9.2
Male sex, n (%)	66 (64.1)
Body mass index (kg/m^2)	20.7±3.9
Education level
Lower education (≤6 years)	85 (82.5)
Higher education (>6 years)	18 (17.5)
Percent predicted FEV1	51.9±22.5
Ratio of FEV1/FVC (%)	54.1±12.2
GOLD	Classification	Stagea
	A 28 (27.2)	I 9 (8.8)
	B 20 (19.4)	II 40 (39.2)
	C 17 (16.5)	III 39 (38.2)
	D 38 (36.9)	IV 14 (13.7)
mMRC score	2.0±1.1
CAT score	10.6±6.7
Frequent AEs in the previous year (≥2 times per year)	23 (22.3)
AEs in the previous year (n)	1.0±1.9
Treatment by a pulmonologist in previous 2 years	57 (55.3)
Multiple devices (≥2 devices)	72 (69.9)

Note: Data are shown as the n (%) or as the mean ± standard deviation,

a n=102.

Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; mMRC, modified Medical Research Council; CAT, COPD Assessment Test; GOLD, Global Initiative for Chronic Obstructive Lung Disease; AE, acute exacerbation.

Table 2 Percentages of mistakes per step, total percentages of patients with incorrect inhalation technique per controller device, and multivariate analysis per device

Essential steps	pMDI n=44	pMDI + spacer, n=33	Accuhaler^® n=83	Handihaler^® n=40
Shake inhaler thoroughly	52.3	39.4	NA	NA
Remove the cap and keep inhaler in upright position	11.4	NA	NA	NA
Slide the outer case away until it clicks	NA	NA	4.8	NA
Slide the lever away until it clicks	NA	NA	8.4	NA
Remove cap and insert inhaler correctly into spacer	NA	12.1	NA	NA
Place capsule in the device and turn back mouthpiece	NA	NA	NA	4.9
Push the buttons once	NA	NA	NA	7.3
Breathe out gently to residual volume	54.5	33.3	38.8	17.1
Close lips on inhaler or spacer mouthpiece	0.0	0.0	0.0	0.0
Press the canister at beginning of inhalation	40.9	NA	NA	NA
Hold spacer level and press down firmly on canister once	NA	21.2	NA	NA
Inhale slowly and deeply	27.3	30.3	NA	NA
Inhale forcefully and deeply	NA	NA	36.1	14.6
Hold breath for at least 10 seconds	38.6	24.2	30.1	24.4
Breathe in and out through mouthpiece at least three times	NA	42.4	NA	NA
Patients performing incorrect inhalation techniques	77.3	69.7	63.9	42.5
Odds ratio	4.6	3.1	2.4	1.0
95% confidence interval	1.8–11.8	1.2–8.2	1.1–5.2
P-value	0.001	0.020	0.025

Abbreviations: pMDI, pressurized meter-dose inhaler; NA, not applicable to the device.

Table 3 Risk factors for incorrect inhalation techniques by univariable analysis (n=103)

Variables		n	Incorrect (%)	Crude OR (95% CI)	P-value
Sex	Female	37	83.8	2.2 (0.8–6.2)	0.114
	Male (Ref)	66	69.7
Age	≥70 years	58	81.0	2.1 (0.9–5.3)	0.096
	<0 years (Ref)	45	66.7
Education	Low (≤6 years)	85	80.0	4.0 (1.4–11.6)	0.008
	High (>6 years) (Ref)	18	50.0
Percent predicted of FEV1a	<50	53	77.4	1.4 (0.5–3.3)	0.492
	≥50 years (Ref)	49	71.4
mMRC scoreb	≥2	67	77.6	1.6 (0.7–4.2)	0.279
	<2 (Ref)	34	67.6
CAT scoreb	≥10	54	81.5	2.3 (0.9–5.7)	0.075
	<10 (Ref)	47	66.0
Frequent AE in the previous year (≥2 times/year)	Yes	23	73.9	0.9 (0.3–2.7)	0.916
	No (Ref)	80	75.0
Treatment by a pulmonologist in the previous 2 years	Yes	46	76.1	1.1 (0.5–2.8)	0.780
	No (Ref)	57	73.7
Inhaler device	Multiple	72	77.8	1.7 (0.6–4.2)	0.282
	Single (Ref)	31	67.7

Note: Data are shown as n (%) or the mean ± standard deviation,

a n=102,

b n=101.

Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 second; mMRC, modified Medical Research Council; CAT, COPD Assessment Test; AE, acute exacerbation; OR, odds ratio; ref, reference.

Table 4 Risk factors for incorrect inhalation techniques by multivariable analysis (n=103)

Variables		Adjusted OR (95% CI)	P-value
Sex	Female	1.5 (0.5–4.6)	0.485
	Male (Ref)
Age	≥70 years	1.9 (0.8–5.3)	0.166
	<70 years (Ref)
Education	Low (≤6 years)	4.1 (1.2–13.4)	0.022
	High (>6 years) (Ref)
CAT scorea	≥10	2.3 (0.8–6.3)	0.107
	<10 (Ref)

Note: Data are shown as n (%) or the mean ± standard deviation,

a n=101.

Abbreviations: CAT, COPD Assessment Test; CI, confidence interval; COPD, chronic obstructive pulmonary disease; OR, odds ratio; Ref, reference.

Figure 1 Comparison of incorrect techniques between a routine visit and 1 month after correct use of controller devices in 69 COPD patients (138 devices).

Abbreviations: COPD, chronic obstructive pulmonary disease; pMDI, pressurized meter-dose inhaler; NA, not applicable to the device.