Validation of the 'Test of the Adherence to Inhalers' (TAI) for Asthma and COPD Patients

Altres ajuts: This study was funded by the Integrated Research Asthma Program (PII Asthma) together with the Integrated Research COPD Program (PII COPD) of the Spanish Respiratory Society (SEPAR). Unconditional funding was provided by Chiesi, who did not participate in data collection, interpretation of the results, or writing of the manuscript.Background: To validate the 'Test of Adherence to Inhalers' (TAI), a 12-item questionnaire designed to assess the adherence to inhalers in patients with COPD or asthma. Methods: A total of 1009 patients with asthma or COPD participated in a cross-sectional multicenter study. Patients with electronic adherence ≥80% were defined as adherents. Construct validity, internal validity, and criterion validity were evaluated. Self-reported adherence was compared with the Morisky-Green questionnaire. Results: Factor analysis study demonstrated two factors, factor 1 was coincident with TAI patient domain (items 1 to 10) and factor 2 with TAI health-care professional domain (items 11 and 12). The Cronbach's alpha was 0.860 and the test-retest reliability 0.883. TAI scores correlated with electronic adherence (ρ=0.293, p =0.01). According to the best cut-off for 10 items (score 50, area under the ROC curve 0.7), 569 (62.5%) patients were classified as non-adherents. The non-adherence behavior pattern was: erratic 527 (57.9%), deliberate 375 (41.2%), and unwitting 242 (26.6%) patients. As compared to Morisky-Green test, TAI showed better psychometric properties. Conclusions: The TAI is a reliable and homogeneous questionnaire to identify easily non-adherence and to classify from a clinical perspective the barriers related to the use of inhalers in asthma and COPD