Comment: Current Research in the Epidemiology and Public Health of the Aging -- The Need for More Diverse Strategies.

The article presents various research papers on epidemiology and discusses public health of the aged in the United States. The history of epidemiology and public health is replete with examples of ingenious and brilliant use of available data that were used to answer important questions and that yielded major public health advances. The Davis report on living arrangements is a sophisticated analysis that reveals the limitations of secondary data, albeit more subtle ones, when one are asking complex questions. If the data reflects a national sample, having national data becomes strength of the study. It is important to note that "secondary data" is an imprecise label that covers a great diversity of types and sources of data. The data set has information on some additional variables not previously examined. It becomes important to look at these variables as possible controls or as risk factors.