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 2 Comparison of mean PIF and pressure drop values in overall population

Variable	Breezhaler®	Ellipta®	HandiHaler®
n	97	91	97
R (cmH₂O^0.5[L/min]⁻¹)^a	0.060	0.090	0.163
PIF (L/min)	108 ± 23	78 ± 15	49 ± 9
Range (Min-Max)	54–156	45–109	22–70
Pressure drop at PIF (cmH₂O)	44 ± 18	51 ± 19	67 ± 23
ΔPIF vs Breezhaler® (L/min); 95% CI	–	30; 27 to 32	59; 56 to 62
P-value		< 0.0001	< 0.0001

Data are presented as mean ± standard deviation unless stated otherwise. P-values generated from a paired t-test on comparison of PIF values
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