Detailing Healthcare Claims Data Evidence of Extrapyramidal Symptoms in Medicaid Patients with Schizophrenia after Second-Generation Antipsychotic Medication Initiation

Researchers have used elements of administrative healthcare claims data (e.g., diagnosis codes and medications) to calculate rates of extrapyramidal symptoms (EPS) in patients with schizophrenia who utilize second-generation antipsychotics (SGAs). However, a detailed description of claims-based EPS evidence has not been previously provided, which is the objective of the current study. This descriptive study, using 2016-2020 de-identified multi-state Medicaid administrative claims data, followed patients diagnosed with schizophrenia for 12 months after initiation of SGA therapy to identify and describe the first evidence of EPS. Time to EPS evidence was calculated and continuously-eligible patients were followed for an additional 12 months to examine EPS medication utilization and costs. Following SGA initiation, 13.6% (n = 2,288) of patients had evidence of EPS during the 12-month follow-up period. Mean time to first evidence of EPS after SGA initiation was 103.7 days (sd = 112.2, median = 58). For a majority of patients (n = 1,636, 71.5%), an EPS medication claim was the initial evidence of EPS, rather than an EPS diagnostic claim. Additionally, a quarter of patients (25.3%) in the EPS evidence cohort had a claim for an EPS medication on the same date as SGA initiation, possibly indicating prophylactic prescribing to prevent EPS development. Nearly 93% of those with EPS medication claims were treated with benztropine, while less than 2% received deutetrabenazine or valbenazine (indicated for tardive dyskinesia (TD)). Annual per patient EPS medication expenditures were $804 (sd = 7,080) overall, but only $40 (sd = 104) when excluding the higher-cost TD medications. Nearly 14% of Medicaid patients with schizophrenia who initiated SGA treatment had evidence of EPS based on claims data. The majority of the time, this evidence was derived from a prescription claim for a medication to treat EPS, rather than an EPS diagnostic claim. Prophylactic prescribing for EPS occurred more often than expected and should be explored more fully. While the cost of traditional EPS medications minimally contributes to the overall cost of care in schizophrenia, use of newer TD drugs can substantially increase spending.