Healthcare resource utilization and costs associated with first versus subsequent use of cariprazine for bipolar I disorder

To evaluate the healthcare resource utilization (HRU) and costs of patients who initiated cariprazine as their first versus subsequent atypical antipsychotic (AA) following a bipolar I disorder (BP-I) diagnosis. Adults with a BP-I diagnosis (first claim = index), commercial, Medicare Supplemental, or Medicaid insurance, and ≥1 outpatient cariprazine dispensing were identified from Merative MarketScan database. Cohorts included patients who initiated cariprazine as either their first or subsequent AA after initial BP-I diagnosis. Characteristics were balanced between cohorts using inverse probability of treatment weighting (IPTW). Outcomes evaluated post-index included all-cause and mental health (MH)–related HRU (hospitalizations, emergency department [ED] visits, outpatient visits), total healthcare costs (medical + pharmacy), and treatment patterns. HRU and healthcare costs were reported per patient-year (PPY) and compared between cohorts using rate ratios and 95% CIs estimated using nonparametric bootstrap procedures. Treatment patterns were analyzed descriptively, with standardized differences ≥10% considered important. After IPTW, cohorts included 1,409 patients who initiated cariprazine first and 1,621 patients who initiated cariprazine subsequently; the average (standard deviation, SD) observation period was 678 (373) and 758 (389) days for first and subsequent initiators, respectively. Patients who initiated cariprazine first had 23% fewer all-cause hospitalizations and 28% fewer MH-related hospitalizations PPY (each comparison, <i>p</i> &lt; 0.001). Rates of all-cause and MH-related outpatient visits were significantly lower in patients who initiated cariprazine first versus subsequently (each comparison, <i>p</i> &lt; 0.001), while rates of ED visits were similar. Relative to subsequent initiators, first initiators incurred $2,587 and $2,130 lower all-cause and MH-related total healthcare costs PPY, respectively (each comparison, <i>p</i> &lt; 0.05). Before starting cariprazine, first initiators used fewer BP-I–related medications on average than subsequent initiators (2.6 vs 3.9; standardized difference = 23.9%). Potential coding inaccuracies and residual confounding. In this real-world database analysis, patients with BP-I who initiated cariprazine as their first AA had lower rates of HRU and incurred lower costs than patients who initiated cariprazine as a subsequent AA. Bipolar I disorder is a costly condition. Patients with bipolar I disorder are prone to high healthcare resource use, such as frequent visits to the doctor or hospital. Many atypical antipsychotic drugs, including cariprazine, are used to treat bipolar I. However, the extent to which healthcare resource use and costs vary based on which atypical antipsychotic is prescribed first after diagnosis is unknown. In this study, we used medical insurance claims data to identify adults who received cariprazine as their first atypical antipsychotic, and those with another atypical antipsychotic before starting cariprazine, after being diagnosed with bipolar I. We then compared the number of healthcare visits and medical and drug costs after the initial bipolar I diagnosis between these two groups. Compared to patients who started cariprazine after another atypical antipsychotic, patients who used cariprazine first had fewer visits to the doctor or hospital. The number of visits to the emergency department was similar between the 2 groups. Additionally, medical and drug costs were lower for patients who used cariprazine first compared to those who used other atypical antipsychotics before cariprazine. These results suggest that starting cariprazine as the first atypical antipsychotic for bipolar I disorder may be associated with fewer hospitalizations and doctors visits as well as lower healthcare costs than starting cariprazine after other atypical antipsychotics.