Abstract
<title>Abstract</title> <p>Objective To develop and validate a Family Resilience Scale for intensive care unit (ICU) patients within the Chinese cultural context, enabling assessment of family resilience levels when coping with critical illness. Methods Based on a previously constructed theoretical model of family resilience in ICU patients derived from grounded theory, an initial item pool was generated through literature review and qualitative interviews. Two rounds of Delphi expert consultations (n = 17) were conducted to screen and refine the items. A convenience sample of 300 family members of ICU patients was recruited to complete the questionnaire for reliability and validity testing. Item analysis, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA) were performed to validate and optimize the scale structure. Additionally, average variance extracted (AVE) and composite reliability (CR) were used to assess convergent validity, and the heterotrait-monotrait (HTMT) ratio was applied to evaluate discriminant validity. Item response theory (IRT) with the graded response model (GRM) was employed to further examine item-level measurement properties. Results The final Family Resilience Scale consists of 21 items across three dimensions. The overall scale demonstrated excellent internal consistency, with a Cronbach's α of 0.950, while the subscales showed Cronbach's α values ranging from 0.834 to 0.966. The split-half reliability was 0.581 (Spearman-Brown coefficient = 0.735, Guttman Split-Half coefficient = 0.702). EFA extracted three common factors, accounting for 75.23% of the total variance. CFA indicated a good model fit (χ²/df = 1.18, CFI = 0.993, TLI = 0.992, RMSEA = 0.025, SRMR = 0.037). AVE values for each dimension ranged from 0.52 to 0.61, CR values from 0.86 to 0.92, and HTMT ratios were below 0.90, supporting satisfactory convergent and discriminant validity. IRT analysis demonstrated that the scale is particularly sensitive in identifying families with low-to-moderate resilience levels. Conclusion The newly developed Family Resilience Scale exhibits strong reliability and validity, making it a suitable instrument for assessing family resilience among ICU patients' families. It provides a valuable tool for clinical practitioners to identify vulnerable families and implement targeted supportive interventions.</p>