title: Changes in health care expenditure associated with gaining or losing health insurance.
abstract: BACKGROUND
  Cross-sectional data suggest that changes in health insurance status are associated with expenditures. No national longitudinal analysis has examined this relationship.
  
  
  OBJECTIVE
  To evaluate the association between changes in health insurance status and expenditures.
  
  
  METHODS
  Cohort analyses using the 2000 to 2003 Medical Expenditure Panel Surveys.
  
  
  METHODS
  U.S. civilian noninstitutionalized population.
  
  
  METHODS
  Three 2-year cohorts that included 20,848 adults age 21 to 64 years who were stratified by insurance type (private, public, military, or none): 17,130 participants were insured in both years, 342 participants were insured in year 1 and were uninsured in year 2, 385 participants were uninsured in year 1 and were insured in year 2, and 2991 participants were uninsured in both years. Persons who were insured for longer than 2 months but less than 10 months or who switched insurance type were excluded (n = 4039).
  
  
  METHODS
  Annual health care expenditures (any or none; amount, contingent on any expenditure; and the difference between year 1 and year 2).
  
  
  RESULTS
  Adjusted expenditure probabilities were similar among all participant groups while insured and were higher than those for all participant groups while uninsured: 92.1% (95% CI, 91.4% to 92.7%) in year 1 and 91.8% (CI, 90.9% to 92.5%) in year 2 for persons insured in both years, 74.2% (CI, 71.7% to 76.5%) in year 1 and 74.8% (CI, 72.1% to 77.4%) in year 2 for persons uninsured in both years, and 90.7% (CI, 87.1% to 93.4%) for persons insured in year 1 and 74.6% (CI, 69.4% to 79.2%) for persons uninsured in year 2. The pattern was also consistent for the group that was uninsured in year 1 but insured in year 2. Adjusted annual expenditures among all participant groups with insurance were similar; expenditures among participant groups without insurance were similar but were lower than those among participants with insurance. Consistent differences in expenditures between year 1 and year 2 were observed for all groups.
  
  
  CONCLUSIONS
  Few participants changed insurance status.
  
  
  CONCLUSIONS
  Changing insurance status is associated with changes in expenditures to levels that are similar to those for persons who are continuously insured or uninsured.
authors.affiliation: Department of Family and Community Medicine, University of California, San Francisco, San Francisco, California 94110, USA. lward@fcm.ucsf.edu
authors.forename: Lisa
authors.initials: L
authors.lastname: Ward
authors.forename: Peter
authors.initials: P
authors.lastname: Franks
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005102:Health Expenditures; D006801:Humans; D019458:Insurance Coverage / Q000191:economics*; D007348:Insurance, Health / Q000191:economics*; D016015:Logistic Models; D017057:Medically Uninsured; D008875:Middle Aged; D014481:United States