It's time to choose the study design!: net benefit analysis of alternative study designs to acquire information for evaluation of health technologies.

Uncertainty in the decision-making process for reimbursement of health technologies could be reduced if additional information were available. Although methods to evaluate the monetary value of the uncertainty have been previously described, an economic evaluation of alternative methods to acquire additional information has not yet been thoroughly explored. Should resources be allocated to a retrospective study design or to a randomised controlled trial (RCT) when additional information is deemed justified? We propose an approach for cost-effectiveness analysis of designs of future studies that are required to evaluate health technologies for reimbursement. Biases inherent in study designs are the main factor that differentiates the ability of the studies to predict the technology's benefit. By quantifying this inherent-bias effect, the incremental effectiveness of future studies can be evaluated. Economic consequences of decisions regarding prioritization of the technologies, along with the expected costs incurred by the study's execution, account for the cost component of the equation. Deducting the result retrieved for the retrospective design from that of the RCT design gives the net information benefit.