Asthma: an analysis of high-cost patients.

Objective: To examine characteristics of asthma patients who accounted for 80 percent of national expenditures in 1994 dollars.

Study design: Data were extracted from a comprehensive data source, the 1987 National Medical Expenditure Survey (NMES) of approximately 35,000 individuals.

Patients and methods: Persons of interest were identified using any occurrence of the ICD-9 code 493 or subcategories. Population weighting factors were used to estimate the population in the United States who sought care for the treatment of asthma. Two groups were identified: a high-cost group, which accounted for 80 percent of the direct medical expenditures, and a low-cost group, which represented 20 percent of expenditures. All analyses were performed using SUDAAN software, which takes into account the complex sampling design used in NMES.

Results: Individuals who rated their health as poor or fair were more likely to be in the high-cost group, as compared with those who rated their health as good or excellent (p < .0009). Persons who reported having Medicare, other government, or private insurance were more likely to be in the high-cost group as compared to those with Medicaid and self-pay (p = .01). A person was more likely to be in the high-cost group if he or she used four or more different medications to treat asthma (p < .0001).

Conclusions: Persons with asthma are more likely to have greater medical expenditures if they use four or more medications and have deteriorated health status. Managed care organizations and public programs may find these characteristics useful in targeting asthma prevention and management programs.