Medicare utilization in the United States: PSRO and regional impacts.

Patterns of hospital use, both in general and under the Medicare program, are known to vary significantly among the census regions of the United States. In trying to explain what accounts for these variants, researchers have examined a host of socio-economic, demographic, hospital-level, an other characteristics of the health care delivery system. Their explanations, however, are often divergent, temporally based, and equivocal in nature. In this article the authors measure some of the more important differentials in Medicare admissions, lengths of stay, and days of care, with data taken from between 1974 and 1977, and we illustrate the importance of "geographic forces" in accounting for variations in use. A review and comparative analysis of explanations offered by other researchers is used to help us both identify what these geographic forces are comprised of and suggest several new methodological strategies for studying the uneven use phenomenon.