Objective: The present study summarized research on skill-mix models for nurses and nursing assistants and provided evidence-based recommendations for developing efficient integrated inpatient care services in healthcare institutions. Methods: This study systematically searched the literature in electronic databases for articles published for articles published in the past five years (since 2020). Studies examining skill-mix models involving both nurses and nursing assistants were included in the review. Results: Eight studies met the inclusion criteria. These studies revealed that skill-mix models can reduce nurse workloads, which vary across patient conditions, medical departments, and hospital sizes. The influence of staff composition on nurse workload was particularly pronounced among those caring for older patients with cognitive impairments. Additionally, although higher nursing assistant/nurse ratios were correlated with enhanced patient satisfaction, staff ratios with more nursing assistants than nurses were associated with increased patient mortality. Conclusion: Implementing integrated inpatient care services requires a clear consensus on nursing roles and responsibilities. Because skill-mix models and the number of nurses available influence patient perceptions of care quality, standardized staff ratios must be carefully evaluated.