Inhaler Technique Errors and Their Association with Asthma Control among Adult Patients: A Cross-Sectional Study

Abstract

Background: Incorrect inhaler technique can reduce pulmonary drug deposition and contribute to persistent symptoms despite appropriate prescribing. This study assessed the frequency and pattern of inhaler technique errors and examined their association with Asthma Control Test (ACT) scores among adults with asthma.

Methods: In this cross-sectional study, 100 adults using a pressurised metered-dose inhaler (pMDI), dry-powder inhaler (DPI), or pMDI with spacer demonstrated their usual technique. Device-relevant errors were recorded with a predefined checklist. Asthma was classified as controlled (ACT 20-25), partly controlled (ACT 16-19), or uncontrolled (ACT 5-15). Chi-square, Spearman rank correlation, and Mann-Whitney U tests were used as appropriate.

Results: The mean age was 48.06±13.46 years. At least one technique error was observed in 87 patients (87.0%), and the mean error count was 3.10±2.17. Failure to hold the breath after inhalation was the most frequent error (n=79). Mean ACT score was 18.19±4.97; 44 patients had controlled asthma, 20 partly controlled asthma, and 36 uncontrolled asthma. Error count had a strong inverse correlation with ACT score (rho=-0.991, p<0.001). Asthma-control distribution differed significantly across error categories (chi-square=119.00, p<0.001). Patients with prior inhaler education had fewer errors and higher ACT scores than those without prior education (both p<0.001).

Conclusion: Inhaler technique errors were frequent and closely associated with poorer ACT-based asthma control. Direct observation, correction of device-specific errors, and repeated teach-back education should form part of every asthma review.