Cultural adaptation and psychometric evaluation of the Persian version of the Nursing Nutritional Care Behaviors Scale (NNCB- Scale) in Iranian nurses

Nurses’ nutritional care behaviors are essential for preventing malnutrition and improving health outcomes, particularly among hospitalized older adults. However, despite the growing need to evaluate these behaviors in Iranian healthcare settings, no culturally adapted and psychometrically validated Persian instrument is available for this purpose. This study aimed to culturally adapt and evaluate the psychometric properties of the Persian version of the Nursing Nutritional Care Behaviors Scale (NNCB-Scale) among Iranian nurses. This methodological study was conducted in Iran in 2025. The cultural adaptation process followed the seven-step guideline proposed by Sousa and Rojjanasrirat. Both qualitative and quantitative face and content validity were assessed by the target group and an expert panel. A total of 716 clinical nurses were recruited using stratified random sampling and were randomly divided into two subsamples for Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). EFA was performed using Principal Axis Factoring with oblique rotation, and Exploratory Graph Analysis (EGA) was also applied to further explore the dimensional structure. CFA was conducted to evaluate the model fit. Convergent and discriminant validity were assessed using Composite Reliability (CR) and Average Variance Extracted (AVE), respectively. Reliability was examined through Cronbach’s alpha (α), McDonald’s omega (ω), and test–retest reliability using the Intraclass Correlation Coefficient (ICC). In addition, measurement invariance across gender was examined using multi‑group CFA, and a Random Forest model (RFM) was applied to determine the relative importance of dimensions and individual items. Assessment and Planning, Nutrition Care Implementation and Support, and Assessment and Calculation Skills, explaining 52.85% of the total variance. Exploratory graph analysis confirmed the stability of the identified structure, and confirmatory factor analysis supported good model fit. The Persian NNCB-Scale demonstrated satisfactory internal consistency, test–retest reliability, and convergent and discriminant validity. Measurement invariance across gender was established, indicating comparable performance in male and female nurses. Random Forest analysis identified Nutrition Care Assessment and Planning as the most influential dimension, with items R11 and R17 showing the highest relative importance. The Persian version of the NNCB-Scale demonstrated satisfactory validity and reliability, with a stable three-factor structure, supporting its use as a psychometrically sound instrument for assessing nurses’ nutritional care behaviors. This culturally adapted instrument provides nurse educators, researchers, and healthcare managers with a standardized tool to identify educational needs, evaluate the effectiveness of nutrition-related interventions, and support quality improvement initiatives aimed at enhancing nutritional care for hospitalized older adults.