Background: We aimed to translate, cross-culturally adapt, and validate the General Medication Adherence Scale (GMAS) into Vietnamese. Methods: We followed the guidelines of Beaton et al. during the translation and adaptation process. In Stage I, two translators translated the GMAS to Vietnamese. Stage II involved synthesizing the two translations. Stage III featured a back translation. Stage IV included an expert committee review and the creation of the pre-final version of the GMAS, and in stage V, pilot testing was conducted on 42 Vietnamese patients with type 2 diabetes. The psychometric validation process evaluated the reliability and validity of the questionnaire. The internal consistency and test–retest reliability were assessed by Cronbach’s alpha and Spearman’s correlation coefficients. The construct validity was determined by an association examination between the levels of adherence and patient characteristics. The content validity was based on the opinion and assessment score by the expert committee. The Vietnamese version of the GMAS was created, including 11 items divided into three domains. There was a good equivalence between the English and the Vietnamese versions of the GMAS in all four criteria. Results: One hundred and seventy-seven patients were participating in the psychometric validation process. Cronbach’s alpha was acceptable for all questionnaire items (0.817). Spearman’s correlation coefficient of the test–retest reliability was acceptable for the GMAS (0.879). There are significant correlations between medication adherence levels and occupation, income, and the Beliefs about Medicines Questionnaire (BMQ) score regarding construct validity. Conclusions: The Vietnamese version of GMAS can be considered a reliable and valid tool for assessing medication adherence in Vietnamese patients.

Background: Asthma is a common chronic respiratory disease, reducing the quality of life and increasing the mortality risk of patients. Medication adherence and proper inhaler technique play an important role in asthma control. Objective: To investigate medication adherence, inhaler use, asthma control level, and its related factors among asthma outpatients treated at a specialized tertiary respiratory hospital. Methods: A descriptive cross-sectional study was conducted on asthma outpatients treated at the specialized respiratory hospital (April 1, 2022-June 30, 2022). Medication adherence, inhaler use, and asthma control were assessed using the General Medication Adherence Scale, content-validated checklists, and the asthma control test. Data were analyzed using SPSS software, P value of < 0.05 was considered statistically significant. Results: There were 184 patients included (mean age 48.86 ± 13.28, females 53.8%). More than half of the patients had at least one comorbidity (mainly allergic rhinitis). All patients were prescribed inhaled corticosteroid (ICS) and long-acting beta agonist (LABA) as controller medications, and the most prescribed combination was ICS-LABA + leukotriene receptor antagonist (66.8%). The rates of patients with high medication adherence, proper inhaler technique, and good asthma control were 89.6%, 67.4%, and 75.0%, respectively. The higher medication adherence was associated with better asthma control (odds ratio = 4.584, 95% confidence interval 1.633-12.870, P = 0.004). Small sample size and single-center study may limit the generalizability of the results. Conclusions: Medication adherence was generally high, whereas inhaler technique errors remained common. Despite overall favorable asthma control, ongoing inhaler technique counseling and sustained medication adherence remain essential.