Microsimulation Model

The model was validated with face validity, internal validation, and external validation. The model included health states for no recurrence, resectable recurrence, unresectable recurrence, and death. The study developed an individual-level microsimulation model in R to represent heterogeneity in costs, outcomes, and intervention impact. The models used monthly cycles and a lifetime horizon while emphasizing five-year recurrence outcomes. The model used annual cycles and followed individuals over a lifetime horizon of 90 years. The model did not simulate stage-by-stage disease progression and instead estimated survival from stage-specific mortality probabilities. The model represented nine mutually exclusive health states including breast cancer stages, breast cancer death, and death from other causes. The Inside CKD study used Monte Carlo microsimulation in C++ to project long-term CKD outcomes. The burden model generated a virtual Belgian population of 20 million individuals for 2021 and projected annual outcomes through 2027. Cost-effectiveness cohorts were followed over a lifetime horizon to age 110, with outcomes projected as far as 2086. The study built separate individual-l…