MATERIALS AND METHODS: The cross-sectional validation study utilized a convenience sampling method. Initially, a pre-test was conducted with 25 patients. The MARS-5 was then forward and backward translated following the EORTC QLG translation procedure. The final translated version was reviewed by experts and subjected to a second pre-test. Construct validity was assessed through principal component analysis, and internal consistency was measured using Cronbach's alpha coefficient. Inter-rater reliability was evaluated using the Intra-Class Correlation coefficient (ICC).

RESULTS: The study included 204 cancer patients (ages 18-86, 55% female). The Nepalese version of the MARS-5 was translated without significant issues and underwent pre-testing with participants. Participants discussed the scale during these pre-tests, providing feedback on its clarity and comprehensibility. While formal assessment tools were not employed, the iterative nature of the pre-testing process allowed for the refinement of the translation based on participant feedback, indicating a robust understanding of the scale among participants. The ICC of test-retest reliability was found to be 0.860. The Kaiser Meyer Olkin's value was 0.690, and Cronbach's alpha was 0.72, indicating good construct validity and high internal consistency. The medication non-adherence rate was 11.3%.