Injectable Antipsychotics for Medicaid Patients with Schizophrenia

Tampa—Approximately 74% of patients with schizophrenia are nonadherent to oral antipsychotic medications. Even short treatment gaps with oral antipsychotics are associated with increased relapse risk, and 80% of patients with schizophrenia experience relapse following the discontinuation of antipsychotic treatment.

Long-acting injectable antipsychotics were introduced to provide sustained-release drug dosage to patients, and they have shown improved medication adherence and reduced relapse rates, hospitalizations, and hospital-related costs. Despite the adherence benefits, health plans typically encourage the use of generically available first-generation oral antipsychotics rather than the newly introduced second-generation long-acting injectable antipsychotics.

A recent study sought to evaluate the impact of benefit design restrictions on treatment adherence among Medicaid patients with schizophrenia who initiate treatment with long-acting injectable agents. The results of the study were presented at the AMCP meeting during a poster session titled The Impact of Benefit Design Restrictions on Adherence to Long-Acting Injectable Antipsychotics Among Medicaid Patients With Schizophrenia.

The researchers developed a Microsoft Excel-based model to measure the impact of benefit design restrictions on adherence among long-acting injectable agent users. Model input measurements included initial market share of oral and long-acting injectable antipsychotic agents, treatment adherence, and reduced long-acting injectable agent market share caused by benefit design. Model output measurements included the change in the proportion of long-acting injectable agent users with a proportion of days covered (PDC) ≥80% before versus after benefit design restrictions. Data were collected from the Truven Health Analytics MarketScan^® database between January 1, 2010, and December 31, 2011. Adherence was measured as 1-year PDC.

The study found that in terms of benefit restrictions on the market share of long-acting injectable agents, there was a 50% reduction from 5% to 2.5%. In turn, there was an increase in oral antipsychotic agents from 4% to 6.5%. In terms of benefit restrictions on adherence, when the restrictions were applied, the overall proportion of long-acting injectable agent users with PDC ≥80% decreased from 39.8% to 30.9%.

Limitations of the study include that the analysis focused specifically on the long-acting injectable agents, and it is unclear how oral antipsychotic benefit design restrictions would impact overall adherence.

The researchers concluded that these benefit design restrictions could result in suboptimal treatment adherence and lower quality of care for patients with schizophrenia. They suggested that less restrictive policies may help physicians select the most appropriate treatments to manage their patients.

This study was sponsored by Otsuka America Pharmaceutical, Inc., and H. Lundbeck A/S.