Influence of inhaler technique on asthma and COPD control: a multicenter experience

Figures & data

Table 1 Sociodemographic and disease-related characteristics of the patients observed in nine clinical centers/hospitals

Variable	Total patients 312 (100%)
	Asthma	COPD	P-value*
Number of patients, n (%)	231 (74)	81 (26)	<0.001
Duration of disease in years (mean ± SD)	5.2±1.7	6.5±3.4	ns
Duration of any kind of therapy in years (mean ± SD)	5.4±1.9	5.5±2.3	ns
Duration of therapy with inhaler device in years (mean ± SD)	1.3±0.7	1.1±0.8	ns
M:F ratio	1:1.54
Age in years (mean ± SD)	51.8±17.3

Notes:

* Cities: Belgrade (five centers), Novi Sad (one center), Niš (one center), Kragujevac (one center), Sombor (one center). Mann–Whitney U-test.

Abbreviations: COPD, chronic obstructive pulmonary disease; M:F, male to female ratio; ns, nonsignificant difference; SD, standard deviation.

Table 2 Comorbidities of the study population

Disease	n (%)
Allergic rhinitis	16 (5.1)
Cardiovascular disease	17 (5.4)
Hypertension	63 (20.2)
Diabetes mellitus	12 (3.8)
Gastrointestinal disease	5 (1.6)
Neurological disease	1 (0.3)
Other	2 (0.6)
Without comorbidity	181 (58.0)

Table 3 Risk factors for development of respiratory diseases in the study population

Risk factors	n (%)
Current smoker	48 (15.4)
Ex-smoker	133 (42.6)
Family history for asthma or COPD	103 (33.0)
Allergic rhinitis	16 (5.1)
Exposure to fumes	39 (12.5)
Other	17 (5.4)

Abbreviation: COPD, chronic obstructive pulmonary disease.

Figure 1 Different modalities of patients’ practical education on inhaler device usage during three visits.

Table 4 Correctness of patients’ usage of DPI device in COPD or asthma patients

No of step	Seven steps of inhalation technique	Total no of patients who correctly used DPI device, n (%)			P-value*
		Visit 1	Visit 2	Visit 3
1	Unscrew and lift off the cover, n (%)	307 (98.4)	283 (99.3)	303 (100)	0.066
2	Holding the inhaler upright, n (%)	270 (86.5)	264 (92.6)	296 (97.7)	<0.001
3	Turning the red grip as far as it will go to the right, then turning it as far as it will go to the left. A “click” sound is heard, n (%)	247 (79.4)	266 (93.3)	291 (96)	<0.001
4	Breathing out gently to the end and far from inhaler mouthpiece, n (%)	235 (75.3)	252 (88.4)	288 (95)	<0.001
5	Placing the mouthpiece gently between the teeth, deep breath, n (%)	269 (86.2)	275 (96.5)	297 (98)	<0.001
6	Removing the inhaler from the mouth. Holding breath for about 10 sec. Breathing out, n (%)	244 (78.2)	267 (93.7)	293 (96.7)	<0.001
7	Replacing the cover tightly after use, n (%)	306 (98.1)	282 (98.9)	301 (99.3)	0.236
	Total number of patients per visit	312 (100)	285 (100)	303 (100)

Note:

* Cochran’s Q test.

Abbreviations: COPD, chronic obstructive pulmonary disease; DPI, dry powder inhaler.

Figure 2 Comparison of mean values of inhaler device usage score between visit 1 and visit 2, and visit 1 and visit 3.

Notes: ***Visit 1 versus visit 2, P<0.001, Student’s t-test; ^###visit 1 versus visit 3, P<0.001, t-test.

Abbreviation: CI, confidence interval.

Figure 3 Comparison of global assessment of disease control between visit 1 and visit 2, and visit 1 and visit 3.

Note: ***Visit 1 versus visit 2, P<0.001; ^###Visit 1 versus visit 3, P<0.001, Wilcoxon signed-rank test.

Figure 4 Patients’ questionnaire regarding respiratory disease symptoms (wheezing, coughing, and shortness of breath).

Notes: (A) During the night, (B) during the day, (C) disturbance of everyday activities (percentage of patients and frequency of symptoms in every visit). (A) χ²=10.1, P<0.05; (B) χ²=18.1, P<0.01; (C) χ²=7.8, P=0.096.

Figure 5 Comparison of quality of life score between visit 1 and visit 2, and visit 1 and visit 3.

Notes: ***Visit 1 versus visit 2, P<0.001, Student’s t-test; ^###visit 1 versus visit 3, P<0.001, Student’s t-test.