Development and validation of the core competencies of nephrology specialist nurses questionnaire

Competency assessment is important for training, professional development, and care quality improvement in nephrology nursing, yet standardized and validated assessment tools remain limited. This study aims to develop and validate the self-report Core Competencies of Nephrology Specialist Nurses (CCNSN) questionnaire. A cross-sectional instrument development and validation study is conducted based on classical test theory. The questionnaire is developed through literature review, expert consultation, and cognitive interviews. Nephrology nurses from general tertiary or secondary hospitals in China are recruited in two independent phases, with 407 nurses included for exploratory factor analysis (EFA) and 203 for confirmatory factor analysis (CFA) after outlier removal. Validity and reliability are then evaluated. The final CCNSN includes 19 items across four domains: Nephrology Nursing Expertise, Holistic Care Coordination, Research and Evidence-Based Practice, and Digital Health Integration. The four-factor structure explains 60.95% of the total variance and shows acceptable model fit in confirmatory factor analysis (χ²/df = 1.872, CFI = 0.949, RMSEA = 0.066). Convergent validity is supported by composite reliability values of 0.868–0.909 and average variance extracted values of 0.615–0.646, while discriminant validity is generally acceptable. The total Cronbach’s α is 0.93, and test-retest reliability ranges from 0.71 to 0.82. The CCNSN questionnaire shows satisfactory validity and reliability. It can support self-evaluation, targeted training, professional development, and quality improvement in nephrology nursing, and may provide a useful reference for competency-based workforce development in renal care settings.