Source:http://linkedlifedata.com/resource/umls/id/C0016441
MSH: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.,NCI: Study in which persons exposed to risk or given a designated preventive or therapeutic regimen are observed over a period or at intervals to determine the outcome of the exposure or regimen. (On-line Medical Dictionary)