Trends in the cost of illness for asthma in the United States, 1985-1994

Background: During the past decade, there have been notable changes in asth ma prevalence, morbidity, and mortality. In this same time period, there ha ve also been important national efforts to increase asthma awareness and im prove asthma care. Objective: The purpose of this study was to examine the changes in US cost of illness for asthma during the 10-year period from 1985-1994. Methods: The study was a two-period (1985 and 1994), cross-sectional, cost- of-illness analysis. Cost estimates were based on US population and health care survey data available from the National Center for Health Statistics. Results: The total US costs of asthma for 1994 were $10.7 billion. On the b asis of 1985 estimates adjusted to 1994 dollars, total asthma costs increas ed by 54.1% and direct medical expenditures increased by 20.4% during the 1 0-year period. In 1985, hospital inpatient care represented the largest com ponent cost of direct medical expenditures (44.6%). Hospital inpatient cost s decreased to 29.5% of direct medical expenditures in 1994, primarily beca use of shorter lengths of stay, as opposed to a decrease in the total numbe r of admissions. In 1994, medications represented the largest component cos t of direct medical expenditures (40.1%, up from 30.0% in 1985), The larges t component increase in indirect costs was due to loss of work. On the basi s of adjusted dollars, estimated costs per affected person with asthma decl ined by 3.4% (decrease of 15.5% for children and an increase of 2.9% for pe rsons 18 years and older) during this time period. Conclusion: Although the US costs of asthma increased during the 1985-1994 time period, estimated costs per person with asthma demonstrated a modest d ecline. These findings may represent a combination of reductions in hospita l lengths of stay and increasing prevalence of persons with low consumption of asthma-related health care resources. In examining the component costs, it is unclear whether these changes can be attributed to the many local, r egional, and national efforts aimed at controlling untoward asthma outcomes during the 1985-1994 time period.