Persistent inhaler technique errors in asthma and COPD: a systemic barrier to optimal pulmonary drug delivery

• 50–90 % of asthma and COPD patients commit at least one critical inhaler technique error. • Technique errors persist across four decades despite device innovation and education. • Inhaler misuse contributes to poor disease control, exacerbations, and higher healthcare costs. • Lack of standardization and systemic training deficits limit long-term improvement. • Emerging AI-enabled smart inhalers offer potential to minimize technique variability. Inhaled therapies are the cornerstone of asthma and COPD management due to their targeted pulmonary delivery and reduced systemic effects (GINA/GOLDGuidelines,2024). However, the therapeutic benefit of these drugs is highly dependent on correct user technique. Studies consistently show high rates of misuse, with substantial clinical and economic consequences (PMC6805258,2019). This review synthesizes global evidence on the prevalence, classification, and clinical impact of inhaler misuse across four decades of device evolution and training efforts. It uniquely argues that the persistence of high error rates (50–90 %) represents not a failure of the patient (PMC6805258,2019; Usmanietal.,2018), but a systemic and persistent failure of current device design and intervention models. The review highlights the urgent need for a paradigm shift toward technique-independent drug delivery and closed-loop digital solutions. A narrative review approach was applied to studies published between 1980 and 2025 across PubMed, Scopus, and ScienceDirect. Included studies examined inhaler technique, error rates, outcomes, and interventions among asthma and COPD patients. Comparative analysis was conducted by device type, population, and intervention category. Across four decades of research, 50–90 % of users demonstrated at least one critical inhaler error, most commonly poor coordination, inadequate inspiratory flow, or absence of breath-hold. Despite continuous educational initiatives and device evolution, longitudinal data reveal minimal improvement, with error relapse being common. Misuse correlates strongly with poor symptom control, frequent exacerbations, and elevated healthcare utilization (CRITIKALStudy (Priceetal.), 2017; Rocheetal., 2022). The enduring challenge of inhaler technique errors confirms that traditional educational models are ineffective for long-term behavior modification. Future efforts must prioritize device redesign for inherent simplicity and the widespread implementation of smart technologies that provide objective assessment, real-time feedback, and data integration into clinical care pathways.