Adherence, health care utilization, and costs between long-acting injectable and oral antipsychotic medications in South Carolina Medicaid beneficiaries with schizophrenia
Chao Cai, Chris M Kozma, Charmi Patel, Carmela Benson, Ismaeel Yunusa, Pujing Zhao, Gene Reeder, Meera Narasimhan, Robert L. Bank
Abstract
BACKGROUND: Schizophrenia and schizoaffective disorder require long-term antipsychotic treatment with antipsychotic medications, but poor medication adherence can lead to increased health care utilization and costs. Long-acting injectable antipsychotics (LAIs) offer potential therapeutic advantages in that they require less frequent dosing and improved medication adherence. South Carolina has the highest adoption of LAIs among US states, making it an ideal population for comparing the effectiveness of LAIs vs oral antipsychotics (OAPs) in treating schizophrenia or schizoaffective disorder. OBJECTIVE: To evaluate the effect of LAIs compared with OAPs on medication adherence, health care resource utilization, and costs among South Carolina Medicaid beneficiaries with schizophrenia or schizoaffective disorder. METHODS: South Carolina Medicaid beneficiaries with at least 1 claim for an LAI or OAP between January 1, 2015, and December 31, 2018, aged 18 to 65, with at least 2 claims with diagnoses of schizophrenia or schizoaffective disorder were included. Propensity scores (PSs) were calculated using logistic regression adjusting for confounders and predictors of the outcome. We estimated the "average treatment effect on the treated" by employing PS-weighted t-tests and chi-square tests. RESULTS: < 0.0001). CONCLUSIONS: Among South Carolina Medicaid beneficiaries, treatment with LAIs for schizophrenia or schizoaffective disorder was associated with greater medication adherence rates. Patients using LAIs had higher drug costs and total costs, but lower outpatient and total nondrug costs compared with those using OAPs.