title: Drivers of expenditure growth in outpatient care services.
abstract: OBJECTIVE
  To identify and analyze drivers of costs for healthcare services delivered in outpatient settings.
  
  
  METHODS
  We estimated 2 regression models of state-level annual outpatient expenditures. The first model uses data on operating costs for hospital outpatient services from hospital cost reports. The second model uses outpatient claims data from a large, national, group health insurer, and covers all varieties of outpatient providers for a specific insured population.
  
  
  RESULTS
  Several different cost drivers affected the growth of outpatient costs in the late 1990s. Foremost among the drivers is the change associated with demographics and general economic conditions, and economy-wide inflation, which together accounted for 60% of the growth in outpatient costs. Characteristics directly related to the healthcare sector had a smaller, but still significant role in cost growth. The supply of physicians and specialists accounted for 10% of cost growth, whereas supply and structure of outpatient facilities were responsible for an additional 5% of outpatient cost increase. The health status of the population was associated with 8% of expenditure growth; technology and treatment practices accounted for 7% of growth; and provider operating costs, such as wage levels, were linked to 9% of the growth.
  
  
  CONCLUSIONS
  Some level of growth in outpatient care spending may be cost effective, because outpatient services can substitute for more expensive care in other settings. Strategies for limiting growth in the costs of outpatient care will be more effective if focused on enhancing cooperation between payers, providers, and other stakeholders in assuring an appropriate and cost-effective supply of outpatient care resources.
authors.affiliation: The Lewin Group, Falls Church, Va 22042, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Hearle
authors.forename: Lane
authors.initials: L
authors.lastname: Koenig
authors.forename: Robin
authors.initials: R
authors.lastname: Rudowitz
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Siegel
authors.forename: Allen
authors.initials: A
authors.lastname: Dobson
authors.forename: Silver
authors.initials: S
authors.lastname: Ho
mesh_terms: D000553:Ambulatory Care / Q000191:economics* / Q000706:statistics & numerical data; D003710:Demography; D017048:Health Care Costs / Q000706:statistics & numerical data / Q000639:trends*; D005102:Health Expenditures / Q000706:statistics & numerical data / Q000639:trends*; D006302:Health Services Research; D006801:Humans; D014481:United States