Budget constraint and vaccine dosing: A mathematical modelling exercise

BACKGROUND: Increasing the number of vaccine doses may potentially improve overall efficacy. Decision-makers need information about choosing the most efficient dose schedule to maximise the total health gain of a population when operating under a constrained budget. The objective of this study is to identify the most efficient vaccine dosing schedule within a fixed vaccination budget from a healthcare payer perspective. METHODS: An optimisation model is developed in which maximizing the disease reduction is the functional objective and the constraint is the vaccination budget. The model allows variation in vaccination dosing numbers, in cost difference per dose, in vaccine coverage rate, and in vaccine efficacy. We apply the model using the monovalent rotavirus vaccine as an example. RESULTS: With a fixed budget, a 2-dose schedule for vaccination against rotavirus infection with the monovalent vaccine results in a larger reduction in disease episodes than a 3-dose scheme with the same vaccine under most circumstances. A 3-dose schedule would only be better under certain conditions: a cost reduction of >26% per dose, combined with vaccine efficacy improvement of ≥5% and a target coverage rate of 75%. Substantial interaction is observed between cost reduction per dose, vaccine coverage rate, and increased vaccine efficacy. Sensitivity analysis shows that the conditions required for a 3-dose strategy to be better than a 2-dose strategy may seldom occur when the budget is fixed. The model does not consider vaccine herd effect, precise timing for additional doses, or the effect of natural immunity development. CONCLUSIONS: Under budget constraint, optimisation modelling is a helpful tool for a decision-maker selecting the most efficient vaccination dosing schedule. The low dosing scheme could be the optimal option to consider under the many scenarios tested. The model can be applied under many different circumstances of changing dosing schemes with single or multiple vaccines

Estimating the money flow in the economy attributed to rotavirus disease and vaccination in the Netherlands using a Social Accounting Matrix (SAM) framework

Background: The economics of rotavirus gastroenteritis in infants <5 years old is well-known within healthcare. The financial consequences for families, employers and authorities are not so well explored. The present study evaluates how vaccine prevention changes money flows among e involved in the management of disease, and its consequences. Methods: A Social Accounting Matrix (SAM) framework has been developed reflecting the distribution of income and spending at equilibrium affected by rotavirus disease among all those concerned for 1 year. The data came from official sources and published literature. A comparison of the financial equilibrium between with and without a national rotavirus immunization program has been conducted, along with sensitivity analysis for the results. Results: The total financial cost difference at equilibrium between presence and absence of rotavirus vaccination was +euro26.758 million over one year as a net economic surplus. The payment of vaccination (euro19.194 million) by the government was offset by the increase in tax revenue (euro14.561 million) and by the lower spending in treatment care (euro7.998 million). Conclusion: Studying the financial flows between different transacting agents can demonstrate the financial burden of a disease and the benefits of its prevention on agents' income and spending

Comparing the Analysis and Results of a Modified Social Accounting Matrix Framework with Conventional Methods of Reporting Indirect Non-Medical Costs

Background Assessing the societal perspective in economic evaluations of new interventions requires estimates of indirect non-medical costs caused by the disease. Different methods exist for measuring the labor input function as a surrogate for these costs. They rarely specify the effect of health on labor and who gains and who loses money. Social accounting matrix (SAM) is an established framework that evaluates public policies with multiple perspectives that could help. Objectives We evaluated the use of a modified SAM to assess money flows between different economic agents resulting in economic transactions following policy changes of medical interventions. Methods We compared conventional methods of measuring indirect non-medical costs related to rotavirus vaccination in the Netherlands with a modified SAM framework. To compare the outcome of each method, we calculated returns on investment (ROI) as the net amount of money per euro invested in the vaccine. One-way and probabilistic sensitivity analyses were carried out for each method, focusing on critical variables with the largest impact on indirect cost estimates. Results The ROI was higher for the modified SAM (1.33) than for the conventional methods assessing income calculations (range - 0.178 to 1.22). Probabilistic sensitivity analyses showed wide distributions in the ROI estimates, with variation in the variable impact on the indirect cost results per method selected. Conclusions In contrast to conventional methods, the SAM approach provides detailed and comprehensive assessments of the impact of new interventions on the indirect non-medical costs and the financial interactions between agents, disclosing useful information for different stakeholders.</p

Vaccine impact: Benefits for human health

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A generally applicable cost-effectiveness model for the evaluation of vaccines against cervical cancer

OBJECTIVE: This study aimed at evaluating the cost-effectiveness of human papillomavirus virus (HPV) vaccination in France, using a generally applicable succinct cohort model. METHODS: A lifetime Markov cohort model, adapted to the French setting, simulate the natural history of oncogenic HPV infection towards cervical cancer (CC). Additional modules account for the effects of screening and vaccination. The girls’ cohort is vaccinated at age 12 and follows current screening. Costs and outcomes (discounted at 3 and 1.5%, respectively) were compared with a cohort receiving screening alone. RESULTS: The model results agreed well with real-life data. Vaccination in addition to screening would substantially reduce the incidence of and mortality from CC, compared with screening alone, at an estimated cost-effectiveness of €9,706 per quality-adjusted-life-year. Sensitivity analysis showed that the discount rate and the parameters related to the disease history have the largest impact on the results. CONCLUSION: This succinct cohort model indicated that HPV vaccination would be a cost-effective policy option in France. It uses readily available data and should be generally applicable to the evaluation of HPV vaccination in a variety of countries and settings

Informing decision makers seeking to improve vaccination programs:case-study Serbia

Background: The optimisation of vaccine policies before their implementation is beholden upon public health decision makers, seeking to maximise population health. In this case study in Serbia, the childhood vaccines under consideration included pneumococcal conjugate vaccination (PCV), rotavirus (RV) vaccination and varicella zoster virus (VZV) vaccination.Objective: The objective of this study is to define the optimal order of introduction of vaccines to minimise deaths, quality adjusted life years (QALYs) lost, or hospitalisation days, under budget and vaccine coverage constraints.Methods: A constrained optimisation model was developed including a static multi-cohort decision-tree model for the three infectious diseases. Budget and vaccine coverage were constrained, and to rank the vaccines, the optimal solution to the linear programming problem was based upon the ratio of the outcome (deaths, QALYs or hospitalisation days) per unit of budget. A probabilistic decision analysis Monte Carlo simulation technique was used to test the robustness of the rankings.Results: PCV was the vaccine ranked first to minimise deaths, VZV vaccination for QALY loss minimisation and RV vaccination for hospitalisation day reduction. Sensitivity analysis demonstrated the most robust ranking was that for PCV minimizing deaths.Conclusion: Constrained optimisation modelling, whilst considering all potential interventions currently, provided a comprehensive and rational approach to decision making. (Figure presented.).</p

Informing decision makers seeking to improve vaccination programs:case-study Serbia

Background: The optimisation of vaccine policies before their implementation is beholden upon public health decision makers, seeking to maximise population health. In this case study in Serbia, the childhood vaccines under consideration included pneumococcal conjugate vaccination (PCV), rotavirus (RV) vaccination and varicella zoster virus (VZV) vaccination.Objective: The objective of this study is to define the optimal order of introduction of vaccines to minimise deaths, quality adjusted life years (QALYs) lost, or hospitalisation days, under budget and vaccine coverage constraints.Methods: A constrained optimisation model was developed including a static multi-cohort decision-tree model for the three infectious diseases. Budget and vaccine coverage were constrained, and to rank the vaccines, the optimal solution to the linear programming problem was based upon the ratio of the outcome (deaths, QALYs or hospitalisation days) per unit of budget. A probabilistic decision analysis Monte Carlo simulation technique was used to test the robustness of the rankings.Results: PCV was the vaccine ranked first to minimise deaths, VZV vaccination for QALY loss minimisation and RV vaccination for hospitalisation day reduction. Sensitivity analysis demonstrated the most robust ranking was that for PCV minimizing deaths.Conclusion: Constrained optimisation modelling, whilst considering all potential interventions currently, provided a comprehensive and rational approach to decision making. (Figure presented.).</p