Place of care and costs associated with acute episodes and remission in bipolar I disorder

To our knowledge, literature describing the place of care and associated costs during acute bipolar I disorder (BP-I) episodes is limited. We conducted a claims-based retrospective study to address this gap. Adults with BP-I were identified via IBM MarketScan Commercial and Medicare Supplemental databases. The acute episode index date was defined by ≥1 inpatient BP-I claim(s) or ≥1 outpatient or ≥3 outpatient BP-I claims (depending on visit type) in a 2-week (manic/mixed) or 4-week (depressive) period. Likely acute episodes were defined as 3- and 6-week periods for manic/mixed and depressive episodes, respectively; total mental health-related medical costs (health plan + patient) were collected during these intervals and stratified by setting (inpatient versus outpatient). Initial and subsequent episodes were captured; data were reported in subgroups without and with clozapine use, a proxy for disease severity. The remission index date was the earliest outpatient claim with a bipolar remission diagnosis with no acute episode or treatment. Remission costs were collected over a 3-month period. All results were analyzed descriptively. A total of 41,516 patients with 130,221 acute manic/mixed episodes and 47,763 patients with 149,207 acute depressive episodes met study criteria. Over 84% of acute episodes were treated in outpatient settings. Mental health-related medical costs for manic/mixed episodes were $15,444 for inpatient and $1,577 for outpatient settings; inpatient and outpatient costs for depressive episodes were $17,376 and $2,154, respectively. Health plans covered approximately 78% of medical costs for both episode types with and without prior clozapine use. A total of 8,143 patients met remission criteria; total 3-month outpatient costs were $1,225. Most BP-I acute manic/mixed or depressive episodes were treated in the outpatient setting. Episodes with inpatient care were 8–10 times more costly than outpatient-only episodes. Health plans covered most medical costs, but additional patient-incurred out-of-pocket costs remained.