Hospital Utilization and Expenditures in a Medicaid Population

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Hospital utilization and expenditures in a Medicaid population

Introduction

There have been many studies of hospital utilization and expenditures for the general population but few studies of hospital utilization and expenditures for Medicaid enrollees. Rarely, in studies for either the general or the Medicaid population, are individual-level demographic, attitudinal, health status, diagnostic, source-of-payment, and expenditure data linked to permit multivariate analysis of hospital utilization and expenditures.

In this article, regression analysis is used to examine the determinants of the probability of a hospital visit, the number of hospitalizations, and the total inpatient hospital expenditures for Medicaid enrollees in the States of California, Michigan, New York, and Texas who were continuously enrolled throughout 1980. The data source for this study, the State Medicaid household sample portion of the National Medical Care Utilization and Expenditure Survey, is one of the few data bases containing representative samples of Medicaid enrollees in different States and self-reports of utilization and expenditures validated with Medicaid claims data.

The abundance of demographic, health status, income, source-of-payment, and employment information accompanying the data on medical care expenditures and utilization presents the opportunity for a detailed cross-sectional evaluation of the determinants of utilization and expenditures for Medicaid enrollees across four State Medicaid populations. These results can be compared with findings obtained for the general population (e.g., Mauskopf, Rodgers, and Dobson, 1985) as well as for State Medicaid populations (e.g., Kasper, 1986).

Recently, several comparative studies of State Medicaid populations have been based on data from the Tape-to-Tape project, which includes enrollment, claims, and provider data from the Medicaid Management Information Systems of five States: California, Georgia, Michigan, New York, and Tennessee. Hospital utilization and expenditures by condition (Pine, Howell, and Buczko, 1987); long-term care (McMillan et al., 1987; Ray et al., 1987; Burwell et al., 1987); and health care for children covered by Medicaid (Rymer and Adler, 1987) have been examined in these studies. In other studies, aggregate data from Form 2082 submitted to the Health Care Financing Administration have been used to determine the impact of State Medicaid program characteristics on reimbursement, number of recipients, and State program expenditures (McDevitt and Buczko, 1985; Zuckerman, 1987).

Hospital utilization and

expenditure studies

Inpatient utilization of hospitals varies across sex and age groups. In the 1980 National Hospital Discharge Survey, it was found that females had more hospitalizations and shorter lengths of stay than males had (Haupt, 1982). If hospitalizations for deliveries are not considered, hospitalization rates, length of stay, and prevalence of diagnoses were nearly equal for both sexes.

Persons 65 years of age or over are more likely to be hospitalized and have longer stay lengths and higher hospital expenses than younger persons, regardless of sex. Cromwell et al. (1982) found that aged and disabled Supplemental Security Income enrollees had the highest rates of hospitalization and lengths of stay among Medicaid enrollees in Tennessee.

According to the 1980 National Hospital Discharge Survey data (Haupt, 1982), diseases of the circulatory system were a major cause of hospitalization for all adult age groups and were especially prevalent among those 65 years of age or over, accounting for 29 percent of hospitalizations for persons in this age group. Diseases of the digestive system, malignant tumors, and respiratory diseases were also more prevalent as age increased (McCarthy, 1983; Haupt, 1982; Garnick and Short, 1985) and were often associated with the most expensive hospitalizations among the elderly (Hodgson and Kopstein, 1984). …