[Development and reliability and validity testing of the Medication Literacy Scale for patients with chronic heart...

Chronic heart failure (CHF) is characterized by high prevalence, high mortality, and high readmission rates. Optimized combination pharmacotherapy is the main approach to controlling clinical symptoms and reducing mortality and readmission rates. Ensuring medication safety is a top priority in disease management for patients with CHF, and adequate medication literacy is essential for medication safety. At present, there is a lack of disease-specific tools for assessing medication literacy in patients with CHF. This study aims to develop a Medication Literacy Scale for patients with CHF and to test its reliability and validity, thereby providing a reference for medication use in patients with CHF.

An initial item pool was established through literature analysis and group discussion. Items were optimized using qualitative methods, including Delphi expert consultation and cognitive interviews, and quantitative methods, including item analysis and exploratory factor analysis. Reliability was then evaluated using the Kuder-Richardson formula 20 (KR-20), split-half reliability, and test-retest reliability. Validity was assessed in terms of content validity, criterion-related validity, and construct validity.

The Medication Literacy Scale for patients with CHF consisted of 4 dimensions and 13 items, including 4 items for functional literacy and 3 items each for communicative literacy, critical literacy, and numeracy. A dichotomous scoring method was used, with a total score of 13; higher scores indicated higher levels of medication literacy among patients with CHF. The KR-20 coefficient of the total scale was 0.794, the split-half reliability was 0.701, and the test-retest reliability was 0.842. The item-level content validity index ranged from 0.90 to 1.00, the scale-level content validity index was 0.92, and the criterion-related validity coefficient was 0.739. The chi-square/degrees of freedom ratio was 1.472, the root mean square residual was 0.009, the root mean square error of approximation was 0.049, the goodness-of-fit index was 0.942, the adjusted goodness-of-fit index was 0.908, and both the comparative fit index and incremental fit index approached 0.9.

The Medication Literacy Scale for patients with CHF has a scientific theoretical basis, a standardized development process, and good reliability and validity. It can be used to assess medication literacy in patients with CHF. Clinical practitioners may use this scale to evaluate the overall level of medication literacy and the levels of each dimension among patients with CHF, thereby providing targeted medication guidance and ensuring medication safety in this population.