1. A system for producing structured clinical information from patient records, the system comprising: at least one data source having patient information, at least some of the patient information being unstructured and at least some of the patient information being structured; a data miner operable to (a) search for multiple pieces of information from both structured and unstructured data of the patient information and (b) combine the multiple pieces of information into a value of a variable, the value being a function of the multiple pieces; wherein one or both of (a) and (b) are performed as a function of domain-specific criteria.