Development of the Nursing Nutritional Care Behaviors Scale (B-NNC) in Italian and Psychometric Validation of Its German Translation in Austria

<b>Background/Objectives</b>: Malnutrition among older adults remains a significant healthcare issue, yet existing questionnaires primarily measure knowledge and attitudes rather than actual behaviors. This study aimed to develop the Nursing Nutritional Care Behaviors Scale (B-NNC Scale) in its original Italian version, translate it into German, and evaluate its psychometric properties in registered nurses and nurse assistants in Austria. <b>Methods</b>: This study followed a two-phase, multi-method design. In Phase 1 (Development Phase), the scale was developed in Italian through a scoping review, expert focus group, and content validation involving 18 clinical nutrition experts using the Content Validity Ratio (CVR). In Phase 2 (Validation Phase), the scale was translated into German through a cross-cultural adaptation process, pilot-tested, and psychometrically validated in a sample of 1072 nurses and nurse assistants working in Austrian hospitals across various clinical settings. Exploratory and confirmatory factor analyses (EFA and CFA) were performed to assess construct validity, measurement invariance between professional roles was tested, and internal consistency was measured using McDonald's Omega. <b>Results</b>: Content validity was confirmed with a mean CVR of 0.634. EFA suggested a three-factor solution-(1) Nutritional Assessment and Calculation Skills, (2) Nutritional Evaluation and Care Planning, and (3) Nutritional Support and Care Implementation-leading to the retention of 19 items. CFA supported this structure, and McDonald's Omega indicated high internal consistency across subgroups. Partial measurement invariance revealed some differences in response patterns between registered nurses and nurse assistants. <b>Conclusions</b>: The B-NNC Scale demonstrated robust validity and reliability in measuring self-reported nursing behaviors related to nutritional care in older adults. It addresses a notable gap in existing instruments and may serve as a valuable tool for research and practice to improve malnutrition management.