Characteristics and hospital utilization of the Oklahoma Medicare population: 1994-1996

Epidemiologic surveillance reports that focus on hospital utilization are limited in number. The objective of this study was to provide a current profile of the demographic characteristics of the Oklahoma Medicare population and to profile trends in hospital utilization.

Using the Medicare enrollment files and discharge claims data sets for 1994 through 1996, demographic characteristics and surveillance measures were calculated for enrollees based on age, sex, race/ethnicity, principal diagnosis, and primary procedure. In addition, average hospital charge and average reimbursement were evaluated by diagnosis-related group.

The Oklahoma Medicare population has grown by 2.5% from 1994 through 1996. The majority (87.5%) of the enrollees are aged 65 or greater. Of those less than 65 years of age, most are enrolled in the program because of disability. Less than 5% of the Medicare population was enrolled in a managed care plan during 1996. The overall length of stay, in-hospital mortality, and 30-day mortality rates have declined for all age groups and principal diagnoses profiled. More than one fifth of all of the Medicare discharge claims were related to heart disease.

The Medicare discharge claims files represent a useful source of data from which to conduct surveillance on this population. The declining rates of mortality and length of stay that were demonstrated for all Medicare age groups must be taken into account in any evaluation of health care services that seeks to address the impact of quality improvement or utilization management strategies over time.