The primary purpose of natural history models is to map out the typical progression of a disease. This involves identifying various stages, such as exposure, incubation, symptomatic period, and recovery or chronicity. Understanding these stages helps in estimating the burden of disease, planning healthcare resources, and guiding policy decisions. For instance, during the COVID-19 pandemic, natural history models were essential for projecting the spread of the virus and the impact of different public health measures.
