Patterns of care and costs of switching oral antipsychotic medications in patients with schizophrenia initiating monotherapy treatment: A US claims analysis.

BACKGROUND: Antipsychotic medications are the mainstay of schizophrenia therapy but may need to be changed over the course of a patient's illness to achieve the desired therapeutic goals or minimize medication side effects. Investigations of real-world treatment patterns and economic consequences associated with antipsychotic changes, including switching, are limited.

OBJECTIVE: To describe treatment patterns among patients with schizophrenia who initiated oral antipsychotic medication (OAM) monotherapy and assess switching-related health care resource utilization (HCRU) and costs in US Medicare Advantage and commercially insured patients.

METHODS: Adults with at least 2 claims with a schizophrenia diagnosis who initiated (or reinitiated after ≥6 months) OAM monotherapy between January 1, 2015, and June 30, 2021, were identified in the Optum Research Database. A claims-based algorithm using timing of therapies and treatment gaps identified medication changes, specifically OAM monotherapy switches, among OAM initiators over a period of up to 7 years. Patients who switched from their initial OAM monotherapy to a second OAM monotherapy (initial OAM switchers) were matched based on clinical and demographic characteristics to OAM initiators who had not switched OAMs; switch-related HCRU and costs (incurred up to 3 months before and 3 months after the initial OAM switch) were compared between matched initial OAM switchers and nonswitchers.

RESULTS: Among 6,425 OAM monotherapy initiators, 1,505 (23.4%) had at least 1 OAM monotherapy switch at any time during follow-up, with a mean (SD) time to first switch of 209 (333) days (median, 67 days), a rate of 0.65 switches per person-year of follow-up, and 56% of first switches occurring within 3 months of OAM initiation. Of all OAM initiators, 947 (14.7%) were initial OAM switchers. Compared with 865 matched nonswitchers, 865 initial OAM switchers had greater mean counts of all-cause medical visits and greater mean counts of schizophrenia-related emergency and inpatient visits and longer inpatient stays per patient per month. Mean (SD) total schizophrenia-related costs per patient per month were $1,252 ($2,602) for switchers compared with $402 ($2,027) for nonswitchers ( P < 0.001).

CONCLUSIONS: Changes to antipsychotic therapy in our sample of patients with schizophrenia were common, with nearly one-fourth switching OAMs, the majority within the first 3 months of therapy. Initial OAM switchers experienced greater HCRU and costs than nonswitchers. These findings highlight the importance of initiating OAM monotherapy that effectively maintains symptom control and minimizes tolerability issues, which would limit the need to switch OAMs and therefore prevent excess HCRU and treatment costs.