Neonatal nurses’ developmental support care for preterm infants in South Korea: Path analysis based on the theory of planned behavior

Purpose This study aimed to test a path model explaining neonatal intensive care unit (NICU) nurses' performance of developmental support care (DSC) for preterm infants based on the theory of planned behavior (TPB), incorporating competence and knowledge as additional factors. Background DSC promotes growth and neurodevelopment in preterm infants, yet its implementation among NICU nurses varies. Identifying the mechanisms influencing DSC performance can inform interventions to improve care quality. Methods A cross-sectional survey was conducted with 188 NICU nurses from six university hospitals in South Korea. Validated instruments measured DSC-related knowledge, attitudes, subjective norms, perceived behavioral control, intention, competence, and performance. Path analysis was conducted to examine the hypothesized relationships among variables. Based on modification indices and theoretical considerations, the model was refined by adding a path from intention to competence. Results The final model explained 62.5% of the variance in DSC performance and 46.5% of the variance in competence. The modified model showed suboptimal global fit (RMSEA = .17, TLI = .80), while explaining a substantial proportion of variance in DSC performance. Competence showed the strongest direct association with performance, whereas attitudes, subjective norms, and perceived behavioral control were associated with performance through intention. Knowledge was not significantly associated with competence or performance. Conclusions The model suggested that competence may function as a mediating mechanism between TPB-related determinants and DSC performance, consistent with theory-based intervention approaches. These findings suggest that strategies to support DSC implementation may include strengthening competence through experiential learning (e.g., simulation-based training) and enhancing intention by fostering positive attitudes and a supportive team culture. Future research should replicate this model across settings to develop and evaluate DSC promotion programs.