Device use errors with soft mist inhalers: A global systematic literature review and meta-analysis

Inhaled bronchodilators are the cornerstone of treatment for chronic obstructive pulmonary disease (COPD). Soft mist inhalers (SMIs) are devices that deliver bronchodilators. Although correct device use is paramount to successful medication delivery, patient errors are common. This global systematic literature review and meta-analysis examined device use errors with SMIs among patients with obstructive lung diseases. PubMed, EMBASE, PsycINFO, Cochrane, and Google Scholar were searched to identify studies published between 2010 and 2019 that met the following inclusion criteria: (a) English language; (b) a diagnosis of COPD, bronchitis, or emphysema; and (c) reported device use errors among adults receiving long-acting bronchodilator treatment with Respimat® SMI (i.e. Spiriva®, Stiolto®, Spiolto®, and Striverdi®). Descriptive statistics examined sociodemographics, clinical characteristics, and device use errors. Meta-analysis techniques were employed with random-effects models to generate pooled mean effect sizes and 95% confidence intervals (CIs) for overall and step-by-step errors. The I² statistic measured heterogeneity. Twelve studies (n = 1288 patients) were included in this meta-analysis. Eighty-eight percent of patients had COPD, and most had moderate/very severe airflow limitation (Global Initiative for Chronic Obstructive Lung Disease spirometric stages II to IV). Aggregate results revealed that 58.9% (95% CI: 42.4-75.5; I² = 92.8%) of patients made ≥1 device use errors. Among 11 studies with step-by-step data, the most common errors were failure to (1) exhale completely and away from the device (47.8% (95% CI: 33.6-62.0)); (2) hold breath for up to 10 seconds (30.6% (95% CI: 17.5-43.7)); (3) take a slow, deep breath while pressing the dose release button (27.9% (95% CI: 14.5-41.2)); (4) hold the inhaler upright (22.6% (95% CI: 6.2-39.0)); and (5) turn the base toward the arrows until it clicked (17.6% (95% CI: 3.0-32.2)). Device use errors occurred in about 6 of 10 patients who used SMIs. An individualized approach to inhalation device selection and ongoing training and monitoring of device use are important in optimizing bronchodilator treatment.