Abstract
PURPOSE: Despite increasing awareness, chronic obstructive pulmonary disease (COPD) exacerbations are often unrecognized, not reported or not treated. Assisting patients and caregivers to better identify deteriorations in COPD can help improve care. This study was designed to collect usage and inhalation parameters from albuterol Digihaler devices and its associated Digihaler dashboard, to identify potential inhalation parameters and alerts that might predict worsening COPD. PATIENTS AND METHODS: Real-time rescue albuterol Digihaler (albuterol sulfate) results for peak inspiratory flow (PIF), rescue inhaler usage and inhalation volume (InV) were assessed in 20 COPD patients over 6 months. Alert thresholds from device measurements were analyzed for 14 days prior to all COPD deteriorations defined by a COPD exacerbation or an acute worsening in COPD assessment test (CAT) score. RESULTS: Eleven subjects experienced 22 COPD exacerbations, and 16 subjects experienced 40 CAT score worsening over 6 months' time. No demographic or physiologic differences were identified comparing patients with or without exacerbations or CAT score worsening. Falls in PIF and increases in rescue inhaler usage were weak predictors of impending exacerbations, while a higher percentage (36%) of subjects had a fall in InV prior to an exacerbation. No notable changes in inhaler parameters were associated with deteriorating CAT scores, and no changes in lung function were observed over the study. A combination of 3 alert thresholds was present in 59% of patients within the 2 weeks prior to a COPD exacerbation. CONCLUSION: Our study suggests that alert thresholds based on Digihaler device-measured physiologic parameters may have value in a predictive model for clinical deterioration in COPD.