Reimbursement of Severe Trauma Care Under the SwissDRG Prospective Payment System: 11-Year Evolution of Cost-Reimbursement Adequacy

Background/Objectives: The Swiss Diagnosis-Related Groups (SwissDRG) system, introduced in 2012, aimed to enhance cost transparency and reimbursement efficiency. However, trauma centers treating severely injured patients face financial challenges due to complex care needs and difficulties in estimating appropriate cost weights. This study assessed the adaptability of the SwissDRG prospective payment system since its implementation and identified key drivers of financial deficits in polytrauma care. Methods: We conducted a retrospective cohort study at Lausanne University Hospital, including 382 adult polytrauma patients with an Injury Severity Score ≥ 16, treated from 2012–2019. Reimbursement was evaluated using three methods: MOOS, which grouped the entire population using tariffs from the first three years of SwissDRG implementation; ACTUAL, which compared costs and reimbursements per patient and per year; and RECODED, which simulated updated DRG classifications over an extended 11-year period, up to 2023. Statistical modeling identified the main drivers of financial deficits. Results: The MOOS method showed near-full cost coverage by 2015. The ACTUAL method revealed an average loss of CHF −2751 per patient and a cumulative deficit of CHF −1.05 million over 8 years, with intensive care unit (ICU)-related and polytrauma-specific DRGs as main contributors. In highly complex cases (ISS ≥ 20; 273/382 [71.5%]) mean losses reached CHF −3588. The RECODED method found full cost coverage only in 2021, despite substantial cumulative deficits needing decades of surplus to offset. Conclusions: Current SwissDRG reimbursement remains inadequate for complex trauma care. A more tailored model reflecting ICU costs, outlier penalties, and care complexity is urgently needed to sustain high-quality trauma services in Switzerland.