Development and validation of nutrition knowledge questionnaire for cancer-related anorexia and cachexia syndrome in Taiwanese patients with cancer

Cancer remains a leading cause of mortality worldwide, with over half of patients dying from cancer-related anorexia–cachexia syndrome (CACS). CACS is characterized by progressive weight loss and reductions in muscle and/or fat mass and considerably affects quality of life, prognosis, treatment tolerance, and length of hospitalization. Nutritional consultation or education is a key strategy for managing cancer-related cachexia. However, its effectiveness is determined by several factors, such as patients' nutritional knowledge. To date, no standardized tool has been developed for assessing the nutrition knowledge of patients with cancer specific to CACS. This study developed and validated the Cancer-Related Anorexia and Cachexia Syndrome Nutrition Knowledge Questionnaire (CACSNKQ) to assess patients' understanding of nutrition in the context of cachexia. The initial version of the CACSNKQ comprised 35 items. The validation process involved content validity assessment, item analysis, reliability testing by using the Kuder–Richardson Formula 20 (KR-20), and the criterion-groups technique. Exploratory factor analysis was conducted to identify underlying factors and refine the questionnaire by eliminating items with low factor loadings or cross loadings. The CACSNKQ was validated in a sample of 203 participants. The content validity analysis revealed that item-level content validity indices exceeded 0.80, and internal consistency was strong, with the KR-20 coefficient being >0.80. The exploratory factor analysis yielded a Kaiser–Meyer–Olkin coefficient of 0.869. Following the analysis, the questionnaire was refined to include 21 items, with higher scores indicating greater knowledge of cachexia-related nutrition. The CACSNKQ is a valid and reliable instrument for assessing cachexia-related nutrition knowledge. In clinical practice, this tool can enhance awareness among patients and health-care providers regarding the importance of nutritional knowledge in managing CACS. In academic and research contexts, it can serve as a valuable tool for evaluating the effectiveness of nutrition education programs.