The incidence and economic burden of extrapyramidal symptoms in patients with schizophrenia treated with second generation antipsychotics in a Medicaid population

Abstract

Background Extrapyramidal symptoms (EPS) are common side-effects of second-generation antipsychotics (SGA), that can negatively impact patient quality-of-life, and are associated with increased morbidity and mortality. This study examined the incidence and burden of EPS in patients with schizophrenia initiating SGAs. Methods Patients with schizophrenia initiating SGAs were identified in the MarketScan Multi-state Medicaid database from 1 January 2012 to 31 December 2018. Incidence of EPS (identified via ICD-9/ICD-10 diagnoses and medications) was assessed during the 12-months following SGA initiation. Cohorts with and without EPS were defined. Multivariate models were used to examine all-cause and schizophrenia-related hospitalizations and total costs in the 12 months following the first EPS claim (EPS) or randomly assigned index date (Non-EPS) while controlling for multiple baseline covariates. Logistic regression was used for hospitalization and two-part models were used for skewed cost data. Results A total of 11,642 patients with schizophrenia filled a prescription for an SGA; of which, 2,468 (21.2%) experienced EPS in the first year. The age- and gender-matched EPS group and non-EPS group included 2,295 and 5,607 patients, respectively. Multivariate analyses confirmed that EPS patients had 25% higher odds of all-cause (OR = 1.25; 95% CI = 1.11–1.40) and 75% increased odds of schizophrenia-related (OR = 1.75; 95% CI = 1.53–2.00) inpatient admissions compared to non-EPS patients. Multivariate adjustment of post-period costs between groups also found significant differences in both all-cause (EPS: $27,408 vs. non-EPS: $22,489, p < 0.001) and schizophrenia-related (EPS:$12,833 vs. non-EPS:$8,077, p < 0.0001) costs between the EPS and non-EPS cohorts. Conclusions Over one-fifth of patients initiating treatment with atypical antipsychotics in this study developed EPS in the 12 months following SGA initiation. Extrapyramidal side-effects associated with atypical antipsychotics increase the risk of hospitalization and contribute to higher healthcare costs. For patients with schizophrenia, treatment options that minimize the risk of EPS may reduce the economic burden associated with the disease.