Translation, cross-cultural adaptation, and validation of the Caregiver Indirect and Informal Care Cost Assessment Questionnaire for end-of-life care into Spanish

Abstract Objective This study aims to adapt and validate a Spanish (Argentina) version of the Caregiver Indirect and Informal Care Cost Assessment Questionnaire (CIIQ) to enable the measurement of informal care-related costs in the Argentine context, addressing the current lack of Spanish-language tools for assessing indirect costs. Method The CIIQ was translated, cross-culturally adapted, and validated for the Spanish–Argentine language and culture. Psychometric properties were evaluated in a purposive sample of relatives of patients with advanced chronic disease and limited life expectancy in Argentina. Missing data and internal consistency (Cronbach’s α ) were assessed, along with discriminant capacity, content, and construct validity. Construct validity was examined through principal component analysis (PCA) and confirmatory factor analysis (CFA). Results The translation and cultural adaptation process was completed without major difficulties. A total of 154 caregivers completed the baseline questionnaire and 90 completed the follow-up assessment, with missing data remaining below 10% across items. Internal consistency was high for the overall instrument ( α = 0.802) and for the unpaid care cost domain ( α = 0.866). The productivity loss domain showed moderate reliability ( α = 0.362). Low correlations with unrelated domains ( ρ < 0.2) supported adequate discriminant validity. PCA identified 2 components – informal care costs (51.5% of explained variance) and productivity loss costs (20.3%) – which were further supported by CFA. Significance of results The Spanish–Argentine version of the CIIQ is a reliable and culturally appropriate instrument for assessing the economic burden of informal care in Argentina. While the unpaid care items demonstrated strong psychometric performance, productivity-related items may require refinement to improve reliability in future applications.