Treatment costs related to bipolar disorder and comorbid conditions among Medicaid patients with bipolar disorder.
OBJECTIVE
This study assessed costs among patients with bipolar disorder for treatment related to bipolar disorder and to comorbid conditions. Risk factors associated with costs were also assessed.


METHODS
Data (January 1998 to December 2002) were from a seven-state Medicaid managed care claims database for 13,471 patients who had received a diagnosis of bipolar disorder, most of whom received medications. Each medical claims cost was adjusted by the medical component of the Consumer Price Index as the dollar value in 2002. In a Poisson regression analysis, treatment costs per enrollment month were regressed on patient's age, gender, medications, and clinical comorbidities.


RESULTS
Bipolar disorder treatment accounted for 30% of costs and comorbid disorders for 70%. Key cost components were inpatient care (35%), outpatient care (16%), prescriptions (13%), and physician encounters (11%). Patients with bipolar disorder received a variety of medications: lithium, 13%; anticonvulsants, 35%; second-generation antipsychotics, 24%; first-generation antipsychotics, 22%; and antidepressants, 42%. Compared with the costs for patients receiving antidepressants alone or no medication, the high costs for bipolar disorder treatment and overall treatment were associated with use of second-generation antipsychotics (rate ratio [RR]=1.71, 95% confidence interval [CI]=1.58-1.86 and RR=1.26, CI=1.18-1.34, respectively) and use of anticonvulsants (RR=1.37, CI=1.26-1.48 and RR=1.06, CI=1.00-1.12). Higher costs were significantly associated with key comorbidities, such as drug abuse (RR=1.58, CI=1.47-1.70), cerebral-vascular disease (RR=1.72, CI=1.51-1.94), ischemic heart disease (RR=1.47, CI=1.30-1.66), and hypertension (RR=1.44, CI=1.33-1.56).


CONCLUSIONS
Cost-containment efforts may need to manage or prevent key comorbidities among patients with bipolar disorder and to evaluate the association between antipsychotic use and treatment outcomes and hospital services.
Division of Pharmacy Practice and Administrative Sciences, College of Pharmacy and the Institute for the Study of Health, University of Cincinnati Academic Health Center, 3225 Eden Avenue, Cincinnati, OH 45267-0004, USA. jeff.guo@uc.edu
Jeff J
JJ
Guo
Paul E
PE
Keck
Hong
H
Li
Nick C
NC
Patel
D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000191:economics; D018692:Antimanic Agents / Q000191:economics / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000191:economics* / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D015897:Comorbidity; D003365:Costs and Cost Analysis; D016527:Drug Costs / Q000706:statistics & numerical data; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D008329:Managed Care Programs / Q000191:economics; D008484:Medicaid / Q000191:economics*; D001523:Mental Disorders / Q000191:economics / Q000453:epidemiology; D008875:Middle Aged; D012189:Retrospective Studies; D014481:United States
D018692:Antimanic Agents