Expected Value of Sample Information (EVSI)

The expected value of sample information (EVSI) is a metric used in health economics to estimate the value of collecting additional sample information to reduce uncertainty in a decision-making process. Unlike the expected value of perfect information (EVPI), which assumes the elimination of all uncertainty, EVSI acknowledges that additional research typically only reduces uncertainty rather than eliminating it entirely.

EVSI is calculated to help determine the optimal research design by assessing the potential value of conducting a study with specific parameters, such as:

Study Population: Identifying the characteristics of the population to be studied.

Comparisons to be Tested: Determining the interventions or treatments to be compared.

– Sample Size: Deciding on the number of participants required to achieve meaningful results.

By evaluating these factors, EVSI helps in designing studies that maximize the reduction in uncertainty and provide the greatest value to society. This metric guides decision-makers in allocating resources efficiently to conduct research that will yield the most significant impact on improving healthcare outcomes and cost-effectiveness.

EVSI plays a crucial role in the planning and prioritization of further research, ensuring that the benefits of additional information justify the costs involved. By focusing on the most valuable and feasible studies, EVSI helps enhance the precision of economic evaluations and supports informed healthcare policy and practice decisions.