Incurring greater health care costs: risk stratification of employees with bipolar disorder.

PURPOSE: To compare the costs of employees with bipolar disorder with other employee cohorts and to assess cost differences among employees with bipolar disorder of varying severity.
METHODS: Retrospective data analysis comparing employees with bipolar disorder (cohort 1) with employees without bipolar disorder (cohort 2), employees with other mental disorders (cohort 3), and employees with no mental disorders (cohort 4). Sick leave, short-term disability, long-term disability, and workers' compensation data were used to compare annual lost time and work-absence costs from January 1, 2001, through December 31, 2002. For bipolar disorder severity and risk stratification, quintiles were identified based on total medical and prescription drug costs and analyzed for many health benefits cost categories.
RESULTS: Cohort 1 was the most costly in nearly every health benefits cost category. All comparisons between cohort 1 and cohorts 2, 3, and 4 yielded significant (p ≤ .05) differences except for sick leave costs in cohorts 1 and 3. The aggregate health benefits costs for the highest-cost cohort 1 quintile were $70,616, or 21 times greater than the health benefits costs for the lowest-cost quintile ($3385). Medical comorbidity costs accounted for most of this difference ($51,495; p ≤ .05).
CONCLUSION: Employees with bipolar disorder are the most costly in nearly every health benefits category, with a small minority (2.4%) accounting for 20% of the costs. Employers need to identify and target high-risk ("high cost") employees with bipolar disorder and coexisting conditions that use resources more frequently for appropriate interventions that may include early screening and diagnosis, appropriate treatment, and/or behavioral strategies for improved adherence. These strategies have the potential to improve quality of patient care and reduce costs.