Assessing the Impact of Censoring of Costs and Effects on Health-Care Decision-Making: an Example Using the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Study

OBJECTIVES: Losses to follow-up and administrative censoring can cloud the interpretation of trial-based economic evaluations. A number of investigators have examined the impact of different levels of adjustment for censoring, including nonadjustment, adjustment of effects only, and adjustment for both costs and effects. Nevertheless, there is a lack of research on the impact of censoring on decision-making. The objective of this study was to estimate the impact of adjustment for censoring on the interpretation of cost-effectiveness results and expected value of perfect information (EVPI), using a trial-based analysis that compared rate- and rhythm-control treatments for persons with atrial fibrillation. METHODS: Three different levels of adjustment for censoring were examined: no censoring of cost and effects, censoring of effects only, and censoring of both costs and effects. In each case, bootstrapping was used to estimate the uncertainty incosts and effects, and the EVPI was calculated to determine the potential worth of further research. RESULTS: Censoring did not impact the adoption decision. Nevertheless, this was not the case for the decision uncertainty or the EVPI. For a threshold of $50,000 per life-year, the EVPI varied between $626,000 (partial censoring) to $117 million (full censoring) for the eligible US population. CONCLUSIONS: The level of adjustment for censoring in trial-based cost-effectiveness analyses can impact on the decisions to fund a new technology and to devote resources for further research. Only when censoring is taken into account for both costs and effects are these decisions appropriately addressed.