Costs of physical and mental comorbidities among employees: a comparison of those with and without bipolar disorder

ABSTRACT

Objective: To compare the cost and utilization of health care services for various comorbid conditions among employees with bipolar disorder (BPD) and two other population cohorts: employees without BPD and employees with other mental disorders (OMD).

Methods: Retrospective database analysis on a 2‐year study period, from January 1, 2001, through December 31, 2002 using adjudicated health insurance medical claims on more than 230?000 employees plus their eligible dependents. Study comparisons were performed among employees with BPD (cohort BPD), employees without BPD (cohort NBD), and employees with OMD (cohort OMD). Outcome measures included the cost and utilization of health services for various comorbid conditions as defined by the Agency for Healthcare Research and Quality (AHRQ); using 261 specific categories (SCs) and the 17 Major Diagnostic Categories (MDCs).

Results: Employees in cohort BPD (?n = 761) had greater average annual medical and prescription drug costs than the two other employee cohorts. Costs for cohort BPD were significantly greater (?p ≤ 0.05) than for cohort NBD (?n = 229?145) for six of the 17 MDCs, including the categories of mental disorders ($2036 vs. $65), injury and poisoning ($544 vs. $162), musculoskeletal/connective tissue ($607 vs. $315), other conditions ($274 vs. $134), respiratory system ($217 vs. $104), and nervous system/sensory organs ($225 vs. $119). Similarly, comparisons across AHRQ's 261 SCs found the annual medical costs associated with BPD were greater in 137 (52%) of the 261 categories. Differences between cohort BPD and cohort OMD (?n = 26?776) were significant (?p ≤ 0.05) in three MDCs, with BPD 3.4 times greater than OMD in the mental disorders category: $2036 vs. $596, respectively.

Conclusion: Employees with BPD have greater cost and utilization of services due to various mental and physical comorbidities than either employees without BPD or employees with OMD. The findings are consistent with current literature concerning the comorbidities associated with BPD, and suggest that further longitudinal and observational investigation is necessary to attempt to improve diagnosis and treatment of not only BPD, but also associated targeted diseases commonly found in employees with BPD.