Incremental healthcare costs among patients experiencing adverse events on oral antipsychotics: a real-world analysis of U.S. Medicare beneficiaries with schizophrenia.

Objective: Continuous antipsychotic treatment is fundamental to successful management of schizophrenia. However, many oral antipsychotics are associated with adverse effects (AEs). While prior research has shown antipsychotic AEs to negatively impact patient adherence, no study has examined the incremental costs associated with AEs, especially among Medicare beneficiaries who constitute approximately half of all patients with schizophrenia in the U.S. This study aimed to compare incremental healthcare costs among Medicare beneficiaries with schizophrenia treated with oral antipsychotics who did and did not experience adverse events (AEs).

Methods: All fee-for-service Medicare beneficiaries with schizophrenia who initiated a new OAP between 01/01/2017 and 12/31/2019 were included in the sample (index date = date of new OAP prescription). All-cause and schizophrenia-related costs were measured while a patient was receiving treatment and were converted into monthly measures given differential follow-up periods. Generalized linear models were used to generate adjusted cost estimates.

Results: In our final sample of 46,452 Medicare beneficiaries with schizophrenia, movement disorders such as tardive dyskinesia and extrapyramidal symptoms were observed in 10.0% of beneficiaries. Metabolic side effects included hyperlipidemia (33.6%), diabetes (33.1%), and hypotension (6.8%). Patients who experienced adverse events consistently had significantly higher all-cause monthly healthcare costs compared to patients who did not experience adverse events. This was true for beneficiaries experiencing movement disorders ($5,281 vs. $4,851, Δ = $430, p = 0.0766), hyperlipidemia ($5,123 vs. $4,768, Δ = $355, p = 0.0179), diabetes ($5,249 vs. $4,698, Δ = $551, p = 0.0049), and hypotension ($6,631 vs. $4,685, Δ = $1,946, p < 0.001). A similar pattern was observed for monthly schizophrenia-related costs.

Conclusions: Our findings underscore the additional healthcare cost burden associated with adverse events in patients receiving oral antipsychotic treatment. Efforts should be directed towards selecting agents that minimize side effects and/or developing new therapeutic alternatives with improved tolerability profiles.