The economic burden of influenza is a significant issue within healthcare system, related to higher medical costs particularly among the elderly. Yet, influenza vaccination rates in the elderly in Malaysia were considerably low as it is not part of Malaysia’s national immunization program, with substantial mortality and morbidity consequences. Therefore, we conducted a cost-effectiveness analysis of quadrivalent influenza vaccine (QIV) for the elderly in Malaysia compared with the current no-vaccination policy. A static cost-utility model, with a lifetime horizon based on age, was used for the analysis to assess the cost-effectiveness and health outcomes associated with QIV. Univariate and probabilistic sensitivity analyses were performed to test the effects of variations in the parameters. The use of QIV in Malaysia’s elderly population would prevent 66,326 potential influenza cases and 888 potential deaths among the elderly, leading to 10,048 potential quality-adjusted life years (QALYs) gained. The QIV would also save over USD 4.4 million currently spent on influenza-related hospitalizations and reduce productivity losses by approximately USD 21.6 million. The ICER per QALY gained from a third-party payer’s perspective would be USD 2216, which is lower than the country’s gross domestic product per capita. A QIV-based vaccination program in the elderly was found to be highly cost-effective, therefore would reduce the financial burden of managing influenza and reduce pre-mature death related to this disease.

Background Influenza is a contagious respiratory illness that can cause life-threatening complications among high-risk groups. Estimating the economic burden of influenza is essential to guide policy-making on influenza vaccination programmes, especially in resource-limited settings. This study aimed to estimate the economic burden of influenza on older adults (those aged 60 years) in Malaysia from the provider’s perspective. Methods The main data source in this study was the MY-DRG Casemix database of a teaching hospital in Malaysia. Cases with principal and secondary diagnoses coded in the International Classification of Diseases version 10 (ICD-10) as J09, J10.0, J10.1, J10.8, J11.0, J11.1, J11.8, J12.8, and J12.9, which represent influenza and its complications, were included in the study. The direct cost of influenza at all severity levels was calculated from the casemix data and guided by a clinical pathway developed by experts. The effect of the variations in costs and incidence rate of influenza for both the casemix and clinical pathway costing approaches was assessed with sensitivity analysis. Results A total of 1,599 inpatient and 407 outpatient influenza cases were identified from the MYDRG Casemix database. Most hospitalised cases were aged <18 years (90.6%), while 77 cases (4.8%) involved older people. Mild, moderate, and severe cases comprised 56.5%, 35.1%, and 8.4% of cases, respectively. The estimated average annual direct costs for managing mild, moderate, and severe influenza were RM2,435 (USD579), RM6,504 (USD1,549), and RM13,282 (USD3,163), respectively. The estimated total annual economic burden of influenza on older adults in Malaysia was RM3.28 billion (USD782 million), which was equivalent to 10.7% of the Ministry of Health Malaysia budget for 2020. The sensitivity analysis indicated that the influenza incidence rate and cost of managing severe influenza were the most important factors influencing the total economic burden. Conclusions Overall, our results demonstrated that influenza imposes a substantial economic burden on the older Malaysian population. The high cost of influenza suggested that further efforts are required to implement a preventive programme, such as immunisation for older people, to reduce the disease and economic burdens.