Development and validation of a short form of the medication literacy scale for Chinese College Students

Medication literacy is integral to health literacy, pivotal for medication safety and adherence. It denotes an individual's capacity to discern, comprehend, and convey medication-related information. Existing scales, however, are time-consuming and predominantly cater to patients and community dwellers, necessitating a more succinct instrument. This study presents the development of a brief Medication Literacy Scale (MLS-14) utilizing classical test theory (CTT) and item response theory (IRT), targeting a college student demographic. The MLS-14's abbreviated version, a 6-item scale (MLS-SF), was distilled through CTT and IRT methodologies, engaging 2431 Chinese college students to scrutinize its psychometric properties. The MLS-SF demonstrated a Cronbach's {\alpha} of 0.765, with three extracted factors via exploratory factor analysis, accounting for 66% of the cumulative variance. All items exhibited factor loadings above 0.5. The scale's three-factor structure was substantiated through confirmatory factor analysis with satisfactory fit indices (chi2/df=5.11, RMSEA=0.063, GFI=0.990, AGFI=0.966, NFI=0.984, IFI=0.987, CFI=0.987). IRT modeling confirmed reasonable discrimination and location parameters for all items, free of differential item functioning (DIF) by gender. Except for items 4 and 10, the remaining items were informative at medium theta levels, indicating their utility in assessing medication literacy efficiently. The developed 6-item Medication Literacy Short Form (MLS-SF) proves to be a reliable and valid instrument for the expedited evaluation of college students' medication literacy, offering a valuable addition to the arsenal of health literacy assessment tools.