A decision-theoretic framework for the application of cost-effectiveness analysis in regulatory processes

A Guide to an Iterative Approach to Model-Based Decision Making in Health and Medicine: An Iterative Decision-Making Framework

Decision makers frequently face decisions about optimal resource allocation. A model-based economic evaluation can be used to guide decision makers in their choices by systematically evaluating the magnitude of expected health effects and costs of decision options and by making trade-offs explicit. We provide a guide to an iterative approach to the medical decision-making process by following a coherent framework, and outline the overarching iterative steps of model-based decision making. We systematized the framework by performing three steps. First, we compiled the existing guidelines provided by the ISPOR-SMDM Modeling Good Research Practices Task Force, and the ISPOR Value of Information Task Force. Second, we identified other previous work related to frameworks and guidelines for model-based decision analyses through a literature search in PubMed. Third, we assessed the role of the evidence and iterative process in decision making and formalized key steps in a model-based decision-making framework. We provide guidance on an iterative approach to medical decision making by applying the compiled iterative model-based decision-making framework. The framework formally combines the decision problem conceptualization (Part I), the model conceptualization and development (Part II), and the process of model-based decision analysis (Part III). Following the overarching steps of the framework ensures compliance to the principles of evidence-based medicine and regular updates of the evidence, given that value of information analysis represents an essential component of model-based decision analysis in the framework. Following the provided guide and the steps outlined in the framework can help inform various health care decisions, and therefore it has the potential to improve decision making.

Impact of small study bias on cost-effectiveness acceptability curves and value of information analyses

It is well known that small, randomized, controlled trials (RCTs) have limited validity. When comparing the results of meta-analyses with those of later large trials or with those of large trials removed from the meta-analyses, discrepancies were reported. This paper addresses two issues: (1) how measures of the uncertainty in cost-effectiveness, i.e., cost-effectiveness acceptability curves (CEACs), and the expected value of perfect information (EVPI) are affected by the limited validity of small trials and (2) how to deal with this bias. To this end, the paper adopts a Bayesian approach. Using empirical estimates for the validity of small RCTs compared to larger RCTs, the probability of cost-effectiveness drops by almost 10 %, while the EVPI is three times higher. In conclusion, traditional CEACs and EVPI analyses based on (small) RCTs may need careful appraisal. Ignoring prior evidence on the validity of small-size trials leads to an underestimation of uncertainty in cost-effectiveness. For future economic analyses, it is important to incorporate aspects of uncertainty which are caused by flawed data on effectiveness .

A systematic and critical review of the evolving methods and applications of value of information in academia and practice

OBJECTIVE

This article provides a systematic and critical review of the evolving methods and applications of value of information (VOI) in academia and practice and discusses where future research needs to be directed.

METHODS

Published VOI studies were identified by conducting a computerized search on Scopus and ISI Web of Science from 1980 until December 2011 using pre-specified search terms. Only full-text papers that outlined and discussed VOI methods for medical decision making, and studies that applied VOI and explicitly discussed the results with a view to informing healthcare decision makers, were included. The included papers were divided into methodological and applied papers, based on the aim of the study.

RESULTS

A total of 118 papers were included of which 50 % (n = 59) are methodological. A rapidly accumulating literature base on VOI from 1999 onwards for methodological papers and from 2005 onwards for applied papers is observed. Expected value of sample information (EVSI) is the preferred method of VOI to inform decision making regarding specific future studies, but real-life applications of EVSI remain scarce. Methodological challenges to VOI are numerous and include the high computational demands, dealing with non-linear models and interdependency between parameters, estimations of effective time horizons and patient populations, and structural uncertainties.

CONCLUSION

VOI analysis receives increasing attention in both the methodological and the applied literature bases, but challenges to applying VOI in real-life decision making remain. For many technical and methodological challenges to VOI analytic solutions have been proposed in the literature, including leaner methods for VOI. Further research should also focus on the needs of decision makers regarding VOI.

Probabilistic sensitivity analysis in health economics

Health economic evaluations have recently become an important part of the clinical and medical research process and have built upon more advanced statistical decision-theoretic foundations. In some contexts, it is officially required that uncertainty about both parameters and observable variables be properly taken into account, increasingly often by means of Bayesian methods. Among these, probabilistic sensitivity analysis has assumed a predominant role. The objective of this article is to review the problem of health economic assessment from the standpoint of Bayesian statistical decision theory with particular attention to the philosophy underlying the procedures for sensitivity analysis.

Time to market and patient access to new oncology products in Italy: a multistep pathway from European context to regional health care providers

AIM

The main purpose of this study was to identify each sequential phase followed by an oncology product, from European assessment until to patient access in each Italian region (IR).

METHODS

A panel of oncology products approved by the European Medicines Agency (EMA) in the period 2006-2008 was considered. The explored sequential phases included the times to market for: the EMA; pharmaceutical companies; the Italian Medicines Agency (Agenzia Italiana del Farmaco, AIFA); and IRs as final providers of health care. The IR's time to market was also analyzed by a Cox regression model.

RESULTS

The overall mean time required before patients access was 2.3 years. EMA accounted for the greater proportion of time (31.8%), followed by AIFA (28.2%). However, the duration for both pharmaceutical companies and IRs was associated with the highest variability. An oncology product authorized with a risk-sharing agreement showed an early access in the IRs. On the contrary, the introduction in IRs having a compulsory formulary was delayed. Both a high forecast of economic impact and a high oncology product price can also delay the patient access.

CONCLUSION

The process before patient access to an oncology product is time and cost consuming. This study identifies the main predictors that affect the missing overlap between market and patient access in Italy.