Clinical and cost-effectiveness of an acute medical unit model in Singapore: protocol for a pilot prospective cohort study.

Abstract

Healthcare systems face increasing strain from population ageing, multimorbidity and rising emergency department (ED) attendances. Acute medical units (AMUs) have been adopted internationally to improve patient flow and reduce hospital length of stay, but prospective evidence on their clinical and economic effectiveness remains limited, particularly in Singapore. This study aims to evaluate the clinical outcomes and cost-effectiveness of an AMU model compared with usual care in the general ward at a Singapore tertiary hospital. This is an ongoing single-centre prospective observational cohort study conducted at the National University Hospital, Singapore. Adults admitted non-electively under medical services, whose first admission ward is either the AMU or a general ward, will be recruited and followed for 6 months after index discharge. Recruitment commenced in September 2024 and will continue through December 2025, with final follow-up expected in July 2026. The primary endpoint is total acute-care bed-days within 6 months of index admission, including bed-days accrued during the index admission and any subsequent non-elective acute-care admissions within 6 months of the index admission date. Secondary endpoints include ED reattendance, unplanned readmission, mortality, patient-reported outcomes (EuroQol Five-Dimension Five-Level, WHO-Five Well-being Index, Patient Activation Measure-13, Patient Health Questionnaire-9, Barthel Index and Rapid Estimate of Adult Literacy in Medicine-Short Form), healthcare utilisation and healthcare costs. Because allocation to AMU or general ward care is determined by routine service processes rather than randomisation, comparative analyses will use propensity score inverse probability weighting to reduce measured confounding. Repeated patient-reported outcomes will be analysed using mixed-effects models. The economic evaluation will estimate incremental costs and quality-adjusted life years associated with AMU care compared with usual care over a 6-month period. Ethics approval has been granted by the National Healthcare Group Domain Specific Review Board, Singapore (Reference: 2023/00590). Written informed consent will be obtained from participants or their legally authorised representatives. Findings will be disseminated through peer-reviewed publications, conference presentations and stakeholder engagement and will inform the design of a future multicentre evaluation. NCT07536035.