Validity and reliability of the strain of care for delirium index in intensive care unit nurses: A psychometric testing study.

Background: Delirium poses a considerable clinical challenge in intensive care units (ICUs), imposing substantial burden on nurses caring for patients with delirium. The Strain of Care for Delirium Index (SCDI) measures nursing burden associated with delirium care.Objectives: This study aimed to translate the SCDI into Korean and evaluate the validity and reliability of the Korean version of the SCDI (K-SCDI).Design: Methodological study.Methods: This study translated and culturally adapted the SCDI into Korean in accordance with the World Health Organization guidelines. Six experts assessed content validity (average scale-level content validity index = 0.92). Data were collected from 234 ICU nurses at tertiary hospitals in Busan and Changwon, South Korea. Construct validity was assessed through confirmatory factor analysis, discriminant validity testing, and known-group validity examination. Reliability was evaluated using Cronbach's α and intraclass correlation coefficients (ICCs).Results: Confirmatory factor analysis supported the original four-factor structure (hypoactive behavior, hypoalert behavior, fluctuating course and psychoneurotic behavior, and hyperactive/hyperalert behavior), achieving acceptable model fit indices (χ2/df = 2.25, Tucker-Lewis index = 0.93, comparative fit index = 0.94, root mean square error of approximation = 0.07). Similarly, discriminant validity was supported, with squared correlations between all factors lower than their respective average variance extracted values. Known-group validity was demonstrated in the hyperactive/hyperalert behavior domain, with nurses with and without delirium care education showing significant differences (t = -2.75, P<.05). Internal consistency reliability was excellent (Cronbach's α = 0.91), and test-retest reliability was strong (ICC = 0.87).Conclusion: The K-SCDI is a valid reliable instrument for measuring strain in ICU nurses caring for patients with delirium. This tool can inform the development of nurse support programs, tailored educational interventions, and workplace improvements based on delirium behavioral subtypes.