Clinical Burden of Chronic Obstructive Pulmonary Disease in Patients with Suboptimal Peak Inspiratory Flow

Table 2

Summary of dyspnea measures, health status, and pulmonary function test in participants with oPIF and sPIF against the medium-low resistance DPIs.

	oPIF	sPIF	value
mMRC score, mean (95% CI [n])	1.6 (1.4–1.7 [250])	2.1 (2.0–2.2 [273])	<0.001
BDI, mean (95% CI [n])	6.1 (5.8–6.3 [234])	5.1 (4.9–5.4 [272])	<0.001
Total CAT score, mean (95% CI [n])	19.5 (18.6–20.4 [250])	21.5 (19.7–23.3 [68])	0.05
SGRQ score, mean (95% CI [n])	50.0 (47.9–52.1 [250])	52.8 (48.8–56.8 [68])	0.22
Post-IPR percent predicted FEV1, mean (95% CI [n])	54.7 (52.9–56.5 [252])	39.8 (37.9–41.8 [273])	<0.001
Post-IPR percent predicted FVC, mean (95% CI [n])	75.9 (74.1–77.7 [252])	66.2 (64.4–68.0 [273])	<0.001

oPIF was defined as PIF >60 L/min and sPIF as PIF ≤60 L/min. BDI = baseline dyspnea index; CAT = COPD Assessment Test; CI = confidence interval; DPI = dry powder inhaler; FEV₁ = forced expiratory volume in 1 second; FVC = forced vital capacity; IPR = ipratropium; mMRC = modified Medical Research Council; oPIF = optimal PIF; PIF = peak inspiratory flow; SGRQ = St. George’s Respiratory Questionnaire; sPIF = suboptimal PIF.