title: Chronic disease medication use in managed care and indemnity insurance plans.
abstract: OBJECTIVE
  To evaluate the impact of managed care on the use of chronic disease medications.
  
  
  METHODS
  Claims data from 1997 from two indemnity and three independent practice association (IPA) model managed care insurance plans.
  
  
  METHODS
  Cross-sectional analysis of claims data.
  
  
  METHODS
  Adult patients with diabetes mellitus (DM, n = 26,444), congestive heart failure (CHF, n = 7,978), and asthma (n = 9,850) were identified by ICD-9 codes. Chronic disease medication use was defined through pharmacy claims for patients receiving one or more prescriptions for drugs used in treating these conditions. Using multiple logistic regression we adjusted for patient case mix and the number of primary care visits.
  
  
  RESULTS
  With few exceptions, managed care patients were more likely to use chronic disease medications than indemnity patients. In DM, managed care patients were more likely to use sulfonylureas (43 percent versus 39 percent for indemnity), metformin (26 percent versus 18 percent), and troglitazone (8.8 percent versus 6.4 percent), but not insulin. For CHF patients, managed care patients were more likely to use loop diuretics (45 percent versus 41 percent), ACE inhibitors or angiotensin receptor blockers (50 percent versus 41 percent), and beta-blockers (23 percent versus 16 percent), but we found no differences in digoxin use. In asthma, managed care patients were more likely to use inhaled corticosteroids (34 percent versus 30 percent), systemic corticosteroids (18 percent versus 16 percent), short-acting beta-agonists (42 percent versus 33 percent), long-acting beta-agonists (9.9 percent versus 8.6 percent), and leukotriene modifiers (5.4 percent versus 4.1 percent), but not cromolyn or methylxanthines. Statistically significant differences remained after multivariate analysis that controlled for age, gender, and severity.
  
  
  CONCLUSIONS
  Chronic disease patients in these managed care plans are more likely to receive both inexpensive and expensive medications. Exceptions included older medications partly supplanted by newer therapies. Differences may be explained by the fact that patients in indemnity plans face higher out-of-pocket costs and managed care plans promote more aggressive medication use. The relatively low likelihood of condition-specific medications in both plan types is a matter of concern, however.
authors.affiliation: Stanford Center for Research in Disease Prevention, Stanford University of Medicine, Palo Alto, CA 94306, USA.
authors.forename: Randall S
authors.initials: RS
authors.lastname: Stafford
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Davidson
authors.forename: Harriet
authors.initials: H
authors.lastname: Davidson
authors.forename: Heidi
authors.initials: H
authors.lastname: Miracle-McMahill
authors.forename: Sybil L
authors.initials: SL
authors.lastname: Crawford
authors.forename: David
authors.initials: D
authors.lastname: Blumenthal
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy*; D002908:Chronic Disease / Q000145:classification / Q000188:drug therapy; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000188:drug therapy*; D017723:Drug Utilization Review; D018588:Fee-for-Service Plans / Q000458:organization & administration*; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D007193:Independent Practice Associations / Q000458:organization & administration; D007345:Insurance Claim Review; D016015:Logistic Models; D008297:Male; D008329:Managed Care Programs / Q000458:organization & administration*; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D014481:United States