Health care utilization and costs among patients treated for bipolar disorder in an insured population

Objective: The study examined health care utilization and costs among patie nts treated for bipolar-spectrum disorders in an insured population. Method s: Computerized data on prescriptions and on outpatient and inpatient diagn oses from a large health plan were used to identify patients treated for cy clothymia, bipolar disorder, or schizoaffective disorder. Three age- and se x-matched comparison groups consisting of general medical outpatients, pati ents treated for depression, and patients treated for diabetes were selecte d from health plan members. Utilization and cost of health services for the four groups over a six-month period were assessed using computerized accou nting 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 perc ent of patients accounted for approximately 40 percent of costs for special ty mental health and substance abuse services, 90 percent of inpatient cost s for specialty mental health and substance abuse services, and 95 percent of out-of-pocket costs for inpatient care. In the bipolar disorder group, p arity coverage of inpatient mental health and substance abuse services woul d 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 abus e treatment costs account for this difference. Costs to the insurer and cos ts borne by patients are accounted for by a small proportion of patients. E limination of discriminatory mental health coverage would have a small effe ct on overall health cafe costs.