Source:http://linkedlifedata.com/resource/umls/id/C0023981
MSH: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.,NCI: In medicine, a study or clinical trial in which participants are identified and then followed forward in time.,NCI: Investigation in which data are collected from a number of subjects over a long period of time (a well-known example is the Framingham Study).,NCI: A chronological study in which participants are studied over time, with data being collected at multiple intervals.