Testimony on the need for building an information base on the changing demographics of an aging society in order to make intelligent policy decisions is presented in this Senate committee hearing. Opening statements by Senators Charles Grassley and John Glenn are provided. Jacob A. Brody, dean of the School of Public Health, University of Illinois at Chicago testified on population changes and the need to monitor health and disease in the older population segments. T. Franklin Williams (Director, National Institute on Aging), John G. Keane (Director, Bureau of the Census), Manning Feinleib (Director, National Center for Health Statistics), and Jane Ross (Director, Office of Research, Statistics, and International Policy, Social Security Administration) all testified on coordination among federal agencies on a statistical policy for the aging population and the relevant activities of their agencies. Sam Shapiro (Chairman, Panel on Statistical Requirements for Policy in an Aging Society and Professor Emeritus of Health Policy and Management at the School of Hygiene and Public Health of Johns Hopkins University) and Jack Cornman (Executive Director, Gerontological Society of America) testified on the need for statistical collection by the federal government and submitted written statements and recommendations for a statistical policy. Included in material submitted for the record is a 420-page entry entitled "Inventory of Data Sets Related to the Health of the Elderly" by the National Research Council. (ABL)