Patient-Level Health Economic Modeling in Excel Without VBA: A Tutorial

Cohort-level models in Microsoft Excel^® remain the standard for cost-effectiveness modeling to inform health technology assessment (HTA), despite calls and rationale for more flexible approaches. Their limited ability to capture patient-level characteristics can, in the presence of patient heterogeneity or the need to track patient characteristics to accurately capture a technology's implications, introduce bias. Their continued prevalence is explained by key stakeholders' familiarity with spreadsheet software, and the lower computational burden of cohort-level versus patient-level models. However, contemporary Excel functions have opened up possibilities for calculations within native Excel that enable more flexible, patient-level approaches to be implemented in familiar spreadsheet-based software, without use of any Visual Basic for Applications (VBA) code. Therefore, this tutorial aims to provide step-by-step guidance on how to implement a previously published and freely available individual-level discrete event simulation (DES) in Excel, using contemporary Excel functions and without any VBA code.