Cross-cultural validation and psychometric evaluation of the Self-Medication Assessment Tool (SMAT) for assessing and optimizing medication therapy management of older people

Background, rationale and objectives: The assessment of medication management ability in the elderly can be performed using specific tools, such as the Self-Medication Assessment Tool, which considers real and simulated regimens. The objective of this study was to perform the linguistic and cultural adaptation of the Self-Medication Assessment Tool to European Portuguese and determine its psychometric properties. Methods: The adaptation commenced with the translation/back translation cycle completed by 4 independent bilingual experts. The cultural component was accomplished through an external expert meeting and a longitudinal screening of concepts and construct. The pilot study was carried out in a sample of 150 Portuguese community-dwelling elders. Descriptive data, correlations, internal reliability, response consistency and exploratory factor analysis was conducted using SPSS Statistics (v22). Results: The pilot study was carried out in a sample of 150 community-dwelling elders: 112 (74.7%) participants were women; mean age was 74.73 ± 6.43 years. The Self-Medication Assessment Tool (Portuguese version) standard regimen (simulated medication regimen) mean scores were 20.92 ± 6.83 in functional ability and 38.75 ± 5.92 in cognitive ability; the real regimen (medication taken by the elderly) mean scores were 83.74 ± 15.86 in medication recall, 96.96 ± 11.39 in adherence self-report and 4.82 ± 10.1 in intentional non-adherence. Cronbach's α were 0.87 (functional ability), 0.84 (cognitive ability), 0.57 (medication recall), 0.94 (adherence self-report) and 0.79 (intentional non-adherence). The response consistency between test and re-test was verified. Conclusions: We have developed the European Portuguese version of the Self-Medication Assessment Tool with acceptable psychometric properties which can now be employed in the study of the elderly in clinical and research contexts