The costs of membership aging in a Blue Cross and Blue Shield plan.

One explanation for the tremendous increases in health care costs over the last several years is that an increasingly older population is using a more intense and complex mix of health care services with increased frequency. In this study of Blue Cross and Blue Shield of Michigan membership during the period 1977-1982, age adjustment cost indices were used to quantify the benefit payments attributable to the changes in the average age of the membership during that period. The more thorough understanding of the components of health care cost increases made possible through this method of analysis should promote improved premium arrangements and health care delivery configurations.