ADVISHE: A new tool to report validation of health-economic decision models

Background: Modelers and reimbursement decision makers could both profit from a more systematic reporting of the efforts to validate health-economic (HE) models. Objectives: Development of a tool to systematically report validation efforts of HE decision models and their outcomes. Methods: A gross list of model validation techniques was collected using a literature review, including sources outside the HE field. A panel then selected the most important items. Based on the Delphi method, the panel members could score items in three e-mail rounds. Participants were HE modelling experts, covering various nationalities and work environments. They could comment on relevance, feasibility and formulation of the items and received feedback on comments from others. This resulted in a draft tool of selected items, which was tested and improved in two further rounds. In addition, the Dutch National Health Care Institute commented on usefulness for decision makers, while a separate group of 50 HE experts could comment during a workshop at ISPOR Montreal 2014. Results: 35 Validation techniques were identified and grouped into four categories: conceptual model validation, computerized model validation, data validation and operational validation. Around 30 HE experts commented in each of the first three Delphi rounds, resulting in a 15 item draft tool. The Dutch health care advisory institute suggested to add one more item. Participants from the ISPOR workshop delivered 19 filled-in questionnaires. A fourth round resulted in 17 responses. This led to a refined version containing 16 items, which is currently sent out for a final, fifth round. Conclusions: When filled out by the modellers, AdVISHE (Assessment of the ValIdation Status of Health- Economic decision models) supports model users in assessing the validation status of a model It will be useful as part of reimbursement dossiers, by providing systematic and transparent insight into the validation efforts performed and their results