Prevalence of Low Peak Inspiratory Flow Rate at Discharge in Patients Hospitalized for COPD Exacerbation

Background: Low peak inspiratory flow rate (PIFR) (<60 L/min) among patients with chronic obstructive pulmonary disease (COPD) may result in ineffective medication inhalation, leading to poor bronchodilation. Objective: The objectives of this analysis were to evaluate the prevalence of low PIFR at the time of discharge from a COPD-related hospitalization and to examine the real-world treatment patterns and rehospitalizations by PIFR. Methods: Patients at 7 sites in the United States were screened for enrollment at hospital discharge. PIFR was measured using the InCheck^TM DIAL to simulate resistance of the DISKUS® dry powder inhaler (DPI). An equal number of patients were enrolled into low PIFR (<60 L/min) or normal PIFR (≥60 L/min) cohorts. Demographics, COPD-related clinical characteristics, health status, treatment and rehospitalization data were collected. Results: Mean PIFR was 71±22.12 L/min among 268 screened patients; 31.7% (n=85) of patients had low PIFR. Among all enrolled patients (n=170), the low PIFR cohort was older (66.2±10.04 years versus 62.1±9.41 years, p=0.006) and more likely to be female (61.2% versus 42.4%, p=0.014). There was an increase in DPI use at discharge, compared with admission, in the low PIFR cohort (62.4% versus 70.6%, p=0.020). The incidences of all-cause rehospitalization up to 180 days were similar between the low and normal PIFR cohorts. Conclusions: At discharge following hospitalization for an exacerbation of COPD, approximately one-third of patients had a PIFR <60 L/min. More patients with a low PIFR were discharged with a DPI medication compared with use at admission. There was no difference in the rehospitalization rates by PIFR.