Direct Medical Costs of Hospitalized Dengue Fever in Muscat Governorate, Oman (2022-2023): A Retrospective Cross-Sectional Cost-of-Illness Study

Objectives: Dengue fever (DF) is a re-emerging mosquito-borne viral infection posing a major public health concern in tropical and subtropical regions, including Oman. While the clinical burden is well documented, data on its economic impact remain limited, particularly direct medical costs of hospitalized cases. This study estimated direct medical costs of managing admitted DF cases in two tertiary hospitals in Muscat Governorate, Oman, during 2022–2023 from provider perspective. Methods: A retrospective, cross-sectional cost-of-illness study used national surveillance and hospital electronic records. Laboratory-confirmed dengue patients admitted during 2022–2023 were included. Costs were estimated using a bottom-up micro-costing approach. Results: Among 345 hospitalized patients (98.6% locally acquired), total direct medical costs were OMR 113,097 (~ INT$ 628,316 using 2024 World Bank PPP conversion factor for private consumption), Mean per-patient costs increased from OMR 173 in 2022 to OMR 301 in 2023. Laboratory investigations (53%) and hospitalization (34%) dominated costs, and hospital stay accounted for most of the total costs. Costs were substantially higher in severe dengue (Group C), patients with complications, and those aged ≥ 50 years. Cluster analysis revealed five patient profiles, with the highest costs in older age with severe disease and complications. Conclusions: Hospitalized dengue imposes a substantial and increasing economic burden on Oman's healthcare system. Early diagnosis, outpatient management of mild cases, and targeted prevention for high-risk groups could help reduce avoidable hospitalizations and costs, informing resource allocation and policy.