The integration of retrieval-augmented generation (RAG) into healthcare systems represents a transformative approach to enhancing the reliability, interpretability, and safety of artificial intelligence (AI)-driven clinical analytics. By combining large language models (LLMs) with external knowledge retrieval mechanisms, RAG mitigates hallucinations inherent in standalone generative models, ensuring outputs are grounded in verifiable evidence from electronic health records (EHRs), clinical guidelines, and peer-reviewed literature. This narrative review synthesizes recent advancements in RAG applications for healthcare, focusing on evidence-grounded strategies, tailored evaluation metrics, and robust safety controls to facilitate trustworthy deployment in high-stakes medical environments. Evidence grounded in RAG frameworks involves dynamic retrieval of contextually relevant information to inform generative responses, thereby improving factual accuracy in tasks such as clinical summarization, decision support, and patient education. Studies demonstrate that RAG-enhanced LLMs outperform traditional models in extracting key clinical insights from EHRs, with applications spanning orthopedic patient education, neurosurgical consultations, and precision oncology treatment matching. For instance, integrating vector databases with LLMs enables real-time querying of molecular data to align therapeutic recommendations with patient-specific profiles, reducing errors in evidence-based practice. However, the efficacy of grounding depends on the quality of retrieved sources, necessitating hybrid retrieval techniques that balance semantic similarity and domain-specific relevance. Evaluation metrics for RAG in healthcare extend beyond conventional natural language processing benchmarks to incorporate clinical validity, coherence with medical knowledge, and user-centric outcomes. Metrics such as faithfulness scores, which assess alignment between generated content and retrieved evidence, have been adapted for biomedical contexts, revealing improvements in accuracy for tasks like fitness assessments and diabetes education. Safety controls are paramount, encompassing bias mitigation through multi-agent conversational frameworks, privacy-preserving retrieval in federated systems, and hallucination detection via uncertainty quantification. Regulatory perspectives emphasize the need for standardized safety benchmarks to prevent misinformation in patient-facing tools. This review highlights systems-level insights, including closed-loop architectures where RAG facilitates iterative feedback between data ingestion, inference, and clinical intervention. Challenges in scalability, such as computational overhead in resource-constrained settings, are addressed through optimized retrieval pipelines. We propose an original interpretive framework for RAG deployment, emphasizing interoperability with existing healthcare infrastructures to enhance analytics workflows. Ultimately, RAG holds promise for democratizing AI in healthcare, provided rigorous evaluation and safety protocols are embedded from design to implementation, paving the way for equitable, evidence-driven clinical intelligence.