Hospitals seek to compare performance on operational metrics and quality indicators, but sharing granular patient-level, unit-level, or institution-level data raises privacy, legal, reputational, and competitive concerns. Privacy-preserving analytics has therefore become increasingly relevant for health systems that need collective insight without centralized pooling of sensitive data. This systematic review examines privacy-preserving models used for operational benchmarking, quality monitoring, resource planning, and multi-institutional performance comparison in healthcare. The review focuses on federated analytics, federated learning, secure multi-party computation, differential privacy, homomorphic encryption, and secure aggregation. A PRISMA 2020-compliant search was designed for PubMed, Scopus, IEEE Xplore, and Web of Science covering studies published from 2017 to 2025. Records were screened by two reviewers, and eligible studies were synthesized narratively by application domain, privacy-preserving method, implementation maturity, and operational relevance. Federated learning and secure aggregation dominated the literature, with more recent work increasingly combining federated workflows with differential privacy, homomorphic encryption, or governance frameworks. Most studies addressed clinical prediction or biomedical analytics, while fewer directly examined operational benchmarking, capacity planning, or routine multi-hospital performance comparison. The technical foundations for privacy-preserving federated analytics are increasingly mature, but their translation into routine healthcare operations remains early. Evidence is strongest for multi-site clinical modeling and weakest for sustained operational benchmarking, resource planning, and governance-tested deployment.
Accurate prediction of demand for emergency, imaging, pharmacy, laboratory, and inpatient services is critical for hospital planning. However, forecasting models are typically built separately by department or institution, which limits their ability to learn from shared demand patterns. Hospitals generate rich operational demand streams, but patient-level data cannot usually be pooled across organizations. This creates a need for collaborative forecasting methods that preserve institutional control over sensitive operational records. This article proposes a federated multi-task learning framework for predicting service demand across multiple hospital units. The framework trains a shared predictive model across hospitals while each institution contributes only protected model updates. The framework includes local data adapters, a shared temporal learning backbone, task-specific forecasting heads, a federated aggregation layer, differential privacy mechanisms, and site-specific personalization modules. Together, these components support collaborative forecasting without transferring patient-level operational data. The framework could improve demand prediction by learning common temporal patterns across hospitals and service lines. It would also support local adaptation, reduce duplicated model development, and preserve data confidentiality. A privacy-preserving, collaborative approach to hospital demand forecasting could become a core infrastructure for multi-site operational coordination. Federated multi-task learning offers a practical conceptual foundation for such a system.