Growth and Adaptation of Newly Graduated Nurses Based on Duchscher’s Stages of Transition Theory and Transition Shock Model: A Longitudinal Quantitative Study

<b>Background:</b> The transition from student to registered nurse is a vulnerable period characterised by emotional strain, role ambiguity, and transition shock. Although Graduate Nurse Transition Programs (GNTPs) aim to strengthen early practice readiness, few evaluations use longitudinal, theory-informed approaches or validated tools. <b>Aim:</b> To examine the professional role development of new graduate nurses (NGNs) across three transition stages within a major Australian health service. <b>Design and Methods:</b> A longitudinal quantitative study guided by Duchscher's Stages of Transition Theory and the Transition Shock Model. A customised 75-item questionnaire-adapted from the Professional Role Transition Risk Assessment Instrument and the Professional and Graduate Capability Framework-was administered at three transition points (March 2020-March 2021). Four domains were assessed: Responsibilities, Role Orientation, Relationships, and Knowledge and Confidence. Descriptive statistics, Principal Component Analysis (PCA), chi-square tests, and multinomial logistic regression identified developmental patterns and predictors of transition stage. <b>Results:</b> PCA supported a four-factor structure consistent with the theoretical domains, explaining 62% of variance. Significant stage-based improvements were found in clinical decision-making (RS6, <i>p</i> = 0.005), managing pressure (RS11, <i>p</i> = 0.003), leadership perception (RO5, <i>p</i> = 0.001), and emotional regulation (RL20, <i>p</i> < 0.001). Regression analysis identified role confusion (RS7, χ² = 18.112, <i>p</i> = 0.001), leadership potential (RL1, χ² = 25.590, <i>p</i> < 0.001), workplace support (RL16, χ² = 12.760, <i>p</i> = 0.013), and critical thinking confidence (KN13, χ² = 10.858, <i>p</i> = 0.028) as strong predictors of transition stage. By Stage 3, most NGNs demonstrated increased autonomy, confidence, and professional integration. A coordinator-to-graduate ratio of 1:12 facilitated personalised mentorship. <b>Conclusions:</b> Findings provide robust evidence for theoretically grounded GNTPs. Tailored interventions-such as early mentorship, mid-stage stress support, and late-stage leadership development-can enhance role clarity, confidence, and workforce sustainability.