Abstract
BACKGROUND: Cognitive impairment represents a significant global health challenge, necessitating early identification through reliable self-report questionnaires. The 26-item Cognitive Difficulties Scale (CDS-26) assesses subjective cognitive complaints but lacks validation in diverse linguistic contexts. In the present research, we systematically conducted the translation, cultural adaptation, and preliminary psychometric evaluation of the CDS-26 for the Persian-speaking elderly population in Iran. METHODS: Utilizing a methodological, cross-sectional design, the CDS-26 was translated into Persian following the International Quality of Life Assessment (IQOLA) protocol, including forward/back translation, expert committee review, and pilot testing. Psychometric evaluation involved 138 community-dwelling elderly participants (age ≥60 years). Construct validity was investigated using confirmatory factor analysis. The reliability of the scale was determined by analyzing its internal consistency through Cronbach's alpha and evaluating temporal stability via the intraclass correlation coefficient in a subgroup of 30 participants. RESULTS: Satisfactory face and content validity were confirmed (CVR ≥0.62, overall CVI = 0.89). Confirmatory Factor Analysis demonstrated excellent to good model fit (CFI = 0.977, RMSEA = 0.066, SRMR = 0.063), supporting the scale's multidimensional structure. The full scale exhibited excellent internal consistency (α=0.954) and test-retest reliability (ICC = 0.993). While age, gender, education, and marital status were not significant predictors, economic status was a crucial determinant: higher income groups reported significantly lower CDS scores (medium income: β=-7.97, P=0.005; high income: β=-16.00, P=0.018). CONCLUSION: The Persian CDS-26 is a valid, reliable, and culturally appropriate instrument for assessing subjective cognitive difficulties in Iranian elderly. This tool is valuable for early identification and monitoring cognitive health in clinical and community settings, highlighting the significant impact of socioeconomic factors on perceived cognitive function.