With this supplemental request, in DPPOS AD/ADRD during 2022-2027, we propose to extend our previous analyses to evaluate the longer-term cost-utility and cost-effectiveness of the three original DPP interventions by incorporating additional data on resource utilization, costs, health states/status, health utilities, and mortality. To support these economic analyses, we will continue to collect information on resource utilization and costs associated with the interventions and with medical care outside the study, and information on health outcomes, health utilities, and survival. Based on the resource utilization and cost data collected during DPP/DPPOS, we will summarize the total healthcare costs associated with each of the three original DPP randomized interventions. As recommended by the Second Panel on Cost-Effectiveness in Health and Medicine (3), healthcare costs will include costs in the formal healthcare sector (e.g., costs associated with implementing and maintaining the DPP/DPPOS interventions, and costs of medical care outside the study), those in the informal healthcare sector (e.g., costs of time spent by participants on exercising and costs of time spent by caregivers), and those in the non-healthcare sector (e.g., costs arising from lost productivity). We will estimate the mean per capita healthcare costs associated with each of the three original DPP randomized interventions over the time course of DPP/DPPOS, and calculate the incremental healthcare costs of the ILS and MET interventions relative to placebo and each other from a healthcare sector perspective and a societal perspective.