Abstract
BACKGROUND: Holistic Nursing Competence (HNC) is a key dimension of professional nursing care, requiring precise and valid assessment tools. This study aimed to translate, culturally adapt, and evaluate the psychometric properties of the Holistic Nursing Competence Scale (HNCS) for use in the Iranian nursing context. METHODS: A methodological and cross-sectional study was conducted between 20 July 2024 to 15 January 2025 202, involving 697 nurses from diverse healthcare settings in Iran. The translation process followed established guidelines, and face and content validity were confirmed by an expert panel. Psychometric validation included Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), Exploratory Graph Analysis (EGA), and Random Forest Model (RFM) analysis. Convergent and discriminant validity were examined using Fornell–Larcker criteria, while reliability was assessed via Cronbach’s alpha, McDonald’s omega, composite reliability (CR), and intraclass correlation coefficient (ICC). Measurement invariance across genders was also tested. This methodological and cross-sectional study employed SPSS, AMOS, and R software to perform EFA, CFA, EGA, and Random Forest analyses. RESULTS: The EFA results confirmed the five-dimensional structure of the instrument, comprising: Staff education and management, Ethically-oriented practice, General aptitude, Nursing care in a team, and Professional development. Factor loadings for all items were above 0.40. The CFA results supported the appropriate fit of the five-factor model of the HNCS. Fit indices, including PCFI = 0.818, PNFI = 0.782, CMIN/DF = 3.17, RMSEA = 0.079, IFI = 0.909, CFI = 0.909, and GFI = 0.901, were all within the acceptable and, in some cases, desirable range, indicating that the proposed factor structure is consistent with the empirical data of the present study. Convergent and discriminant validity were confirmed (CR > 0.7; AVE > MSV). Reliability indices were reported at satisfactory levels (α and Ω > 0.9; ICC > 0.8). EGA also corroborated the five-dimensional structure. The RFM indicated ‘General Aptitude’ contributed most (41%) to predicting HNC. Measurement invariance confirmed structural stability across genders. CONCLUSION: The Persian version of the HNCS was identified as a valid and reliable instrument for assessing holistic nursing competence in the Iranian context. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12912-025-03951-8.