title: Health care utilization and costs among patients treated for bipolar disorder in an insured population.
abstract: OBJECTIVE
  The study examined health care utilization and costs among patients treated for bipolar-spectrum disorders in an insured population.
  
  
  METHODS
  Computerized data on prescriptions and on outpatient and inpatient diagnoses from a large health plan were used to identify patients treated for cyclothymia, bipolar disorder, or schizoaffective disorder. Three age- and sex-matched comparison groups consisting of general medical outpatients, patients treated for depression, and patients treated for diabetes were selected from health plan members. Utilization and cost of health services for the four groups over a six-month period were assessed using computerized accounting records.
  
  
  RESULTS
  Total mean+/-SD costs for patients in the bipolar disorder group ($3,416+/-$6,862) were significantly higher than those in any of the comparison groups. Specialty mental health and substance abuse services accounted for 45 percent of total costs in the group with bipolar disorder (mean+/-SD=$1, 566+/-$3,243), compared with 10 percent in the group with depression. Among patients treated for bipolar disorder, 5 percent of patients accounted for approximately 40 percent of costs for specialty mental health and substance abuse services, 90 percent of inpatient costs for specialty mental health and substance abuse services, and 95 percent of out-of-pocket costs for inpatient care. In the bipolar disorder group, parity coverage of inpatient mental health and substance abuse services would increase overall health care costs by 6 percent.
  
  
  CONCLUSIONS
  Health care costs for patients with bipolar disorder exceed those for patients treated for depression or diabetes, and specialty mental health and substance abuse treatment costs account for this difference. Costs to the insurer and costs borne by patients are accounted for by a small proportion of patients. Elimination of discriminatory mental health coverage would have a small effect on overall health care costs.
authors.affiliation: Center for Health Studies of the Group Health Cooperative of Puget Sound, Seattle, Washington 98101, USA. simon.g@ghc.org
authors.forename: G E
authors.initials: GE
authors.lastname: Simon
authors.forename: J
authors.initials: J
authors.lastname: Unützer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001714:Bipolar Disorder / Q000191:economics* / Q000628:therapy*; D003866:Depressive Disorder / Q000191:economics / Q000628:therapy; D003922:Diabetes Mellitus, Type 1 / Q000628:therapy; D001330:Electronic Data Processing; D005069:Evaluation Studies as Topic; D005260:Female; D006279:Health Maintenance Organizations / Q000191:economics*; D006801:Humans; D008297:Male; D008605:Mental Health Services / Q000191:economics* / Q000706:statistics & numerical data*; D008875:Middle Aged; D014861:Washington