Comparison of peak inspiratory flow rate via the Breezhaler®, Ellipta® and HandiHaler® dry powder inhalers in patients with moderate to very severe COPD: a randomized cross-over trial

Table 3 Comparison of mean PIF and pressure drop values based on severity of COPD

Severity	Variable	Breezhaler®	Ellipta®	HandiHaler®
Severity	R (cmH₂O^0.5[L/min]^− 1)^a	0.060	0.090	0.163
Moderate	n	49	44	49
	PIF (L/min)	109 ± 26	78 ± 15	50 ± 10
	Range (Min–Max)	54–152	45–102	22–68
	Pressure drop at PIF (cmH₂O)	45 ± 20	52 ± 19	68 ± 25
	ΔPIF vs Breezhaler® (L/min); 95% CI	–	31; 26 to 34	59; 54 to 64
	P-value		< 0.0001	< 0.0001
Severe	n	38	37	38
	PIF (L/min)	110 ± 22	79 ± 15	49 ± 8
	Range (Min–Max)	71–156	48–109	31–70
	Pressure drop at PIF (cmH₂O)	45 ± 17	53 ± 19	67 ± 22
	ΔPIF vs Breezhaler® (L/min); 95% CI	–	31; 26 to 33	61; 55 to 65
	P-value	–	< 0.0001	< 0.0001
Very severe	n	10	10	10
	PIF (L/min)	99 ± 14	71 ± 13	46 ± 7
	Range (Min–Max)	77–128	52–102	33–59
	Pressure drop at PIF (cmH₂O)	36 ± 10	42 ± 17	58 ± 17
	ΔPIF vs Breezhaler® (L/min); 95% CI	–	28; 24 to 32	53; 46 to 60
	P-value	–	< 0.0001	< 0.0001

Data are presented as mean ± standard deviation unless stated otherwise. P-values for subgroup analysis are exploratory in nature
Poor quality (flat-line) inhalational profiles with erroneous PIF values were not considered in the analysis
CI confidence interval, n number of patients, ΔPIF difference in mean PIF values, PIF peak inspiratory flow rate, R intrinsic airflow resistance of the inhaler
^aData published previously [19, 20]

ISSN: 1471-2466