  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.
