RESUMO
BACKGROUND: Low medication literacy is prevalent among older adults and is associated with adverse drug events. The Medication Literacy Test for Older Adults (TELUMI) was developed and content validated in a previously published study. AIM: To evaluate the psychometric properties and provide norms for TELUMI scores. METHOD: This was a cross-sectional methodological study with older adults selected from the community and from two outpatient services. Descriptive item-analysis, exploratory factor analysis (EFA), item response theory (IRT), reliability, and validity analysis with schooling and health literacy were performed to test the psychometric properties of the TELUMI. The classification of the TELUMI scores was performed using percentile norms. RESULTS: A total of 344 participants, with a mean age of 68.7 years (standard deviation = 6.7), were included; most were female (66.6%), black/brown (61.8%), had low schooling level (60.2%) and low income (55.2%). The EFA pointed to the one-dimensional structure of TELUMI. A three-parameter logistic model was adopted for IRT. All items had an adequate difficulty index. One item had discrimination < 0.65, and three items had an unacceptable guessing index (< 0.35) and were excluded. The 29-item version of TELUMI had excellent internal consistency (KR20 = 0.89). There was a positive and strong association between TELUMI scores and health literacy and education level. The scores were classified as inadequate medication literacy (≤ 10.0 points), medium medication literacy (11-20 points), and adequate medication literacy (≥ 21 points). CONCLUSION: The results suggest that the 29-item version of TELUMI is psychometrically adequate for measuring medication literacy in older adults.
RESUMO
OBJECTIVES: Medication literacy comprises the skills needed to access, understand, and act on medication information. Low medication literacy is frequent among older adults, making them more susceptible to negative health outcomes. The aim of this study was to develop and evaluate the content validity of an instrument to measure medication literacy in this population. METHOD: Multistage methodological study. Items were generated according to a conceptual model and a literature review. The instrument was submitted to a panel of experts to assess item's relevance, clarity, and theoretical classification. Subsequently, the instrument was applied to the target population to assess its comprehensibility. RESULTS: Content Validity Index results indicated excellent agreement among experts on the instrument's relevance (0.98) and clarity (0.91). Overall agreement between experts regarding the theoretical subdimensions was moderate [Fleiss' kappa=0.57 (p = 0.00)]. Items were reported to be fully understood by most representatives of the target population. The final version of the instrument had 33 items divided into eight scenarios of medication use. CONCLUSION: The instrument seems to have adequate content validity and good suitability for the target population. Therefore, it can help health professionals to identify older adults with low medication literacy, aiming to improve their medication use skills.