Value of Information Analysis

Value of Information (VOI) analysis, used in health technology assessment, refers to estimating the value, in terms of cost and health outcomes, of collecting additional data on key parameters influencing a decision, such as the reimbursement of a new technology.

Key points about VOI analysis include:

– Purpose: VOI analysis is most useful when the output of an economic evaluation (e.g., incremental cost-effectiveness ratio or ICER) is uncertain and close to a decision threshold (willingness to pay). The analysis helps determine if new information reducing uncertainty in key parameters will likely lead to better decision-making.

– Focus: It is particularly valuable for parameters with high uncertainty that significantly influence the economic evaluation’s outcome. Collecting additional information on these parameters can improve the chances of making the correct decision regarding a healthcare intervention.

– Application: VOI analysis assesses whether conducting further, potentially expensive, studies (e.g., on effectiveness) is likely to yield useful results that justify the investment. It can guide decisions on whether additional research is warranted and where it should be focused.

Common Outputs:

Expected Value of Perfect Information (EVPI): Measures the value of eliminating all uncertainty about a decision by having perfect information. It represents the maximum amount one should be willing to pay for perfect information.

Expected Value of Partially Perfect Information (EVPPI): Estimates the value of eliminating uncertainty in specific key parameters rather than all parameters. It helps identify which parameters are most worth studying further.

Expected Value of Sample Information (EVSI): Evaluates the value of obtaining additional data from a specific sample to reduce uncertainty. It can help determine the optimal design and size of further studies.


– If an ICER is close to the decision threshold and one key parameter (e.g., drug efficacy) is highly uncertain, VOI analysis can estimate the value of conducting a new trial to gather more precise efficacy data. If the EVSI is high, it suggests that the trial could be a worthwhile investment.


– Informed Decision-Making: Helps prioritize research efforts and allocate resources efficiently by identifying the most valuable data to collect.

– Risk Reduction: Reduces the risk of incorrect decisions by quantifying the value of reducing uncertainty in key parameters.

– Cost-Effectiveness: Ensures that investments in additional research provide a return in terms of improved health outcomes and cost savings.


– Complexity: Performing VOI analysis requires sophisticated probabilistic sensitivity analysis and a thorough understanding of the economic model.

– Data Requirements: Requires detailed and high-quality input data to produce reliable estimates of the value of additional information.

VOI analysis is a powerful tool in health technology assessment, guiding decisions on further data collection and research to reduce uncertainty and improve the quality of healthcare decision-making.