Before revision:  Hidden Markov models (HMMs) and its variants are a class of models that both discover these states and make predictions concerning future states for new patients. HMMs can be trained using longitudinal observations of subjects from large-scale cohort studies, clinical trials, and electronic health records.
After revision:  Hidden Markov models (HMMs) and its variants are a class of models that both discover these states and make inferences of health states for patients.