BACKGROUND: Addiction is a context specific but common and devastating condition. Though several evidence-based treatments are available, many of them remain under-utilized, among others due to the lack of adequate training in addiction medicine (AM). AM Training needs may differ across countries because of difference in discipline and level of prior AM training or contextual factors like epidemiology and availability of treatment. For appropriate testing of training needs, reliability and validity are key issues. The aim of this study was to evaluate the psychometric properties of the AM-TNA Scale: an instrument specifically designed to develop the competence-based curriculum of the Indonesian AM course.

METHOD: In a cross-sectional study in Indonesia, Ireland, Lithuania and the Netherlands the AM-TNA was distributed among a convenience sample of health professionals working in addiction care in The Netherlands, Lithuania, Indonesia and General Practitioners in-training in Ireland. 428 respondents completed the AM-TNA scale. To assess the factor structure, we used explorative factor analysis. Reliability was tested using Cronbach's Alpha, ANOVA determined the discriminative validity.

RESULTS: Validity: factor analysis revealed a two-factor structure: One on providing direct patient treatment and care (Factor 1: clinical) and one factor on facilitating/supporting direct patient treatment and care (Factor 2: non-clinical) AM competencies and a cumulative 76% explained variance. Reliability: Factor 1 α = 0.983 and Factor 2: α = 0.956, while overall reliability was (α = 0.986). The AM-TNA was able to differentiate training needs across groups of AM professionals on all 30 addiction medicine competencies (P = .001).

CONCLUSIONS: In our study the AM-TNA scale had a strong two-factor structure and proofed to be a reliable and valid instrument. The next step should be the testing external validity, strengthening discriminant validity and assessing the re-test effect and measuring changes over time.